Model GWC Gas-Fired Water Boilers Boiler Manual • Installation • Maintenance • Startup • Parts This manual must only be used by a qualified heating installer/service technician. BEFORE installing, read all instructions in this manual and all other information shipped with the boiler. Perform steps in the order given. Failure to comply could result in severe personal injury, death or substantial property damage.
GWC gas-fired water boiler — Boiler Manual How it works . . . 1 Integrated boiler control The integrated boiler control (IBC) responds to signals from the room thermostat, air pressure switch, inlet water sensor and boiler limit circuit to operate the circulators, gas valve, igniter and blower. When a room thermostat calls for heat, the IBC starts the system circulator and blower. The IBC runs the blower to purge the boiler flue passages, then turns on the igniter and lets it warm up.
GWC gas-fired water boiler — Boiler Manual GWC Water Boiler Part number 550-142-056/0411 3
GWC gas-fired water boiler — Boiler Manual Contents How it works . . . . . . . . . . . . . 2 DIRECT VENT — Boiler room air openings . . . . . . . . . . . . . . 36 GWC Water Boiler . . . . . . . . . 3 Please read before proceeding . . 5 Prepare boiler location . . . . . . . 6 Installations must follow these codes: . . . 6 High altitude installations . . . . . . . . . 6 Residential garage installation . . . . . . .
GWC gas-fired water boiler — Boiler Manual Please read before proceeding Failure to adhere to the guidelines on this page can result in severe personal injury, death or substantial property damage. Hazard definitions The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product.
GWC gas-fired water boiler — Boiler Manual Prepare boiler location Installations must follow these codes: • • • Local, state, provincial, national codes, laws, regulations and ordinances. National Fuel Gas Code, ANSI Z223.1- latest edition. Standard for Controls and Safety Devices for Automatically Fired Boilers, ANSI/ASME CSD-1, when required. • National Electrical Code. • For Canada only: B149.1 or B149.2 Installation Code and CSA C22.1 Canadian Electrical Code Part 1 and any local codes.
GWC gas-fired water boiler — Boiler Manual Prepare boiler location (continued) Foundation Figure 4 Provide a solid brick or concrete foundation pad if any of the following is possible: • When the floor can become flooded. • When the boiler mounting area is not level. • When a high-profile condensate pump is used, provide a foundation high enough that the GWC condensate connection is at least as high as the condensate pump inlet connection.
GWC gas-fired water boiler — Boiler Manual Prepare the boiler (continued) Check orifice plate — replace if necessary The correct orifice plate must be used. Failure to do so will result in severe personal injury, death or substantial property damage. The boiler is shipped with a natural gas orifice plate. It MUST BE CONVERTED to use propane. Natural gas: For natural gas installations, inspect the silver gas/air orifice plate marking. It must be the same as the boiler size.
GWC gas-fired water boiler — Boiler Manual Prepare the boiler (continued) Install condensate trap Figure 7 Install condensate trap 1. Before placing the boiler in position, install the condensate trap line, shown in Figure 7. Items shown are provided with the boiler. Step 1 Attach the flue drain hose (C) to the in-line flue drain nipple (B). Step 2 Slide a screw driver or pencil through the condensate drain nipple (G).
GWC gas-fired water boiler — Boiler Manual Prepare the boiler (continued) Install high altitude air pressure switch when required (only above 5,500 feet) Figure 8 Air pressure switch mounting 1. For installations at altitude more than 5,500 feet above sea level: a. A special high altitude air pressure switch is required. b. The gas valve outlet pressure setting must be checked, and adjusted if necessary, per the instructions on page 60.
GWC gas-fired water boiler — Boiler Manual Prepare the boiler (continued) Perform hydrostatic pressure test Figure 10 Piping connections for hydrostatic test Pressure test boiler before attaching water or gas piping (except as noted below) or electrical supply. Remove jacket top panel before proceeding. Use two wrenches when tightening water piping at boiler, using one of the wrenches to prevent the boiler interior piping from turning.
GWC gas-fired water boiler — Boiler Manual Install water piping Use two wrenches when tightening water piping at boiler, using one of the wrenches to prevent the boiler interior piping from turning. Failure to support the boiler piping connections to prevent them from turning could cause damage to boiler components. The cast iron heat exchanger return temperature must be kept at or above 140°F during all times of operation to prevent possibility of corrosion due to condensation.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Figure 13 Relief valve installation guidelines To avoid water damage or scalding due to relief valve operation, as per local or state codes: Discharge line must be connected to relief valve outlet and run to a safe place of disposal. Terminate the discharge line in a manner that will prevent possibility of severe burns or property damage should the valve discharge.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Figure 14 Piping to single-zone system using diaphragm- or bladder-type expansion tank. Boiler connections are 1” NPT (supply from 1” tee, return to 1” recuperator flange). Figure 15 Piping closed-type expansion tank Pipe diaphragm- or bladder-type expansion tanks to the bottom of the separator. Pipe closed-type (air in contact with water) tanks to the top of the air separator.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) System water piping methods Most piping methods shown in this manual use primary/secondary connection to the boiler loop. These designs ensure proper flow through the GWC boiler, for the most efficient and reliable operation of the boiler and the heating system. For other piping methods, consult your local WilliamsonThermoflo representative.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Baseboard system piping — CIRCULATOR zoning (primary/secondary) Figure 17 Baseboard system — circulator zoning Apply Figure 17 for circulator zoning on systems using baseboard heaters. The heaters can be any baseboard style, including finned tube or cast iron. Zoning with circulators — The GWC internal system circulator cannot be removed from the boiler for use as one of the zone circulators.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Figure 18 Zone valve zoning — GWC-070, GWC-105 or GWC-140 (DO NOT apply to GWC-175) Legend 1 Isolation valves 4 Zone valve 2 Automatic air vent (with diaphragm-type expansion tank), or connect to tank fitting (closed-type expansion tank). 7 Hose bibb purge valve 8 Boiler pressure/temperature gauge 10 Differential pressure bypass valve 3 Diaphragm- or bladdertype expansion tank, if used.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Radiator system piping Figure 20 Radiator system — zone-valve zoning Apply Figure 20 (zone-valve zoning) or Figure 21 (circulator zoning) to systems using standing cast iron radiators. This applies to gravity water systems and converted steam systems using columnar, tubular or recessed cast iron radiators.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Single-zone radiant heating or heat pump Radiant heating systems and heat pump systems usually require system supply water temperatures below 140°F. But the boiler outlet water temperature will be at least 150°F to 160°F during most operating conditions. So the piping must include a method of reducing the supply water temperature to the system.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Multi-zone radiant heating system Multi-zone systems require automatic regulation of the system supply temperature because of widely varying load conditions. Figure 23 (zone-valve zoning) and Figure 24 (circulator zoning) show suggested piping for these systems.
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Piping snow melt systems or combination snow melt/space heating systems Figure 25 Auto return temp regulation — circulator zoning Combination snow melt/space heating systems can have return water temperature below 60°F, and the return temperature will fluctuate. So these systems require automatic return water temperature as shown in Figure 25 (zone-valve zoning) or Figure 26 (circulator zoning).
GWC gas-fired water boiler — Boiler Manual Install water piping (continued) Water chiller systems Pipe the boiler and water chiller as shown in Figure 27. Install boiler, as shown, so chilled medium is piped in parallel with heating boiler. Use appropriate valves to prevent chilled medium from entering boiler. See Figure 27 for typical installation of balancing valve and check valve.
GWC gas-fired water boiler — Boiler Manual Multiple boiler installations Placing multiple boilers 1. Locate multiple boilers in boiler room according to: a. Figure 28 (side-to-side), or b. Figure 29 (back-to-back). 2. Provide the clearances indicated in the illustrations listed above to provide for access and servicing. If these recommended dimensions are not possible, provide at least the recommended service clearances given on page 6. Also follow local codes. 3.
GWC gas-fired water boiler — Boiler Manual Multiple boiler water piping Secondary header piping installation 1. Main header and secondary header pipe sizing. a. New system — See page 15. b. Replacing boilers in an existing system — Without reducing size, connect system supply and return lines. Install tees or crosses for secondary headers as shown in Figure 30 or Figure 31. Size headers to handle total connected boiler output as shown.
GWC gas-fired water boiler — Boiler Manual Multiple boiler water piping (continued) Figure 32 Piping schematic — typical for multiple GWC boilers, using secondary headers Legend — Figure 32 1 Flow/check valve (each boiler) 2 Isolation valves (when used) 3 Cap 4 Secondary header (supply) — layout and size per page 24 5 Secondary header (return) — layout and size per page 24 6 Primary circulator 7 Expansion tank (diaphragm type) 8 System air eliminator 11 Check valve or backflow preventer
GWC gas-fired water boiler — Boiler Manual Multiple boiler water piping (continued) Figure 33 Piping layout — typical for multiple GWC boilers, using secondary headers (2-boiler system) Legend — Figure 33 1 2 3 4 5 6 7 8 9 16 26 Flow/check valve (each boiler) Isolation valves (when used) Caps Secondary header (supply) — layout and size per page 24 Secondary header (return) — layout and size per page 24 Primary circulator Expansion tank (diaphragm type) System air eliminator System au
GWC gas-fired water boiler — Boiler Manual Multiple boiler water piping (continued) Figure 34 Piping layout — typical for multiple GWC boilers, with DHW storage heaters (4-boiler system) Suggested DHW boiler-side pipe sizing (for max 0.
GWC gas-fired water boiler — Boiler Manual Multiple boiler water piping (continued) Figure 35 Piping layout — typical for multiple GWC boilers, using isolation exchanger Use isolation heat exchanger for: 1. Large volume systems with high mineral content in water. 2. Systems exposed to untreated quantities of makeup water. 3. Old systems severely contaminated with scale and rust buildup inside piping and heat distribution units. 4. Process applications. 5. Commercial service water applications. 6.
GWC gas-fired water boiler — Boiler Manual Venting & air — general GWC boilers must be vented and supplied with combustion and ventilation air using piping and methods described in this manual. Every boiler must have its own vent. DO NOT common vent with any other appliance. Inspect finished vent and air piping thoroughly to ensure all are airtight and comply with the instructions provided and with all requirements of applicable codes.
GWC gas-fired water boiler — Boiler Manual Venting & air — general (continued) Provide combustion air: Combustion air contamination: DIRECT VENT — The installation must provide combustion air piping. In addition, ventilation openings may be required. Ensure that the combustion air will not contain any of the contaminants in Figure 36. DIRECT EXHAUST — The installation must provide combustion air openings to the boiler space.
GWC gas-fired water boiler — Boiler Manual Venting & air — general (continued) Manifolded combustion air option for DIRECT VENT multiple boiler installations Figure 37 Combustion air manifold option (combined air inlet, but individual vents) — must comply with Figure 41, page 35 1. Multiple GWC boilers can use a common combustion air manifold. a. The combustion air inlet must be located in a sidewall (and the vents must terminate on the same side of the building). b.
GWC gas-fired water boiler — Boiler Manual Venting & air — general (cont.) Figure 39 GWC venting and air piping — OPTIONS and PIPING LIMITS Vent length affects boiler input — the boiler automatically derates to compensate for pressure loss through the vent. See the derate values given in Figure 105, page 99. The longer the vent, the more the input is reduced.
GWC gas-fired water boiler — Boiler Manual Venting & air — general (cont.
GWC gas-fired water boiler — Boiler Manual Commonwealth of Massachusetts installations Commonwealth of Massachusetts — When the boiler is installed within the Commonwealth of Massachusetts, the boiler must be installed by a licensed plumber or gas fitter. Read and comply with the instructions below.
GWC gas-fired water boiler — Boiler Manual Vent termination requirements Figure 41 The vent termination must be located to meet all requirements below (also applies to vertical vent terminations). For Canadian installations, defer to the requirements of CSA B149.1 or B149.2 Installation Code.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Boiler room air openings Figure 42 Combustion and ventilation air openings for GWC Direct Vent installations The GWC boiler CANNOT be in the same space with other appliances if clearances around the GWC are less than the recommended service clearances shown in Figure 2, page 6. Air openings GWC boiler WITH other appliances in room The required air opening sizes below are FREE AREA, after reduction for louver obstruction.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Sidewall with separate pipes Allowable vent/air pipe materials & lengths Figure 43 Installation sequence — Separate pipes sidewall Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 1. Locate the termination such that the total air piping and vent piping from the boiler to the termination will not exceed the maximum length given in Figure 39, page 32. Determine termination location 1.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Sidewall with separate pipes (continued) For multiple boiler applications using the manifolded combustion air option, the vent can be terminated in an elbow as in Figure 43, page 37, or in a coupling or sidewall termination plate. The vents must be located following the restrictions in Figure 41, page 35 and Figure 44 Multiple separate pipes sidewall terminations Figure 38, page 31.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Sidewall with 3” concentric Allowable vent/air pipe materials & lengths Figure 46 Installation sequence — Concentric horizontal 1. The 3” concentric termination kit must be purchased separately. Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 2.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Sidewall with 3” concentric (continued) Install termination — concentric pipes 1. Assemble the vent termination as described for concentric terminations, on page 45. If necessary, you can shorten the lengths of the inner and outer pipes for a shorter finished assembly. But you must ensure the pipes butt correctly at both ends.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Vertical with separate pipes Allowable vent/air pipe materials & lengths Figure 49 Separate pipes vertical termination Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 1. Locate the terminations such that the total air piping and vent piping from the boiler to the termination will not exceed the maximum length given in Figure 39, page 32. Determine termination location 1.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Vertical with separate pipes (continued) 3. Space the air and vent holes to provide the minimum spacings shown in Figure 49, page 41. Figure 50 Terminations for multiple boilers 4. Follow all local codes for isolation of vent pipe when passing through floors, ceilings and roofs. 5. Provide flashing and sealing boots sized for the vent pipe and air pipe. Termination and fittings 1.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Vertical with 3” concentric Allowable vent/air pipe materials & lengths Figure 51 Installation sequence — Concentric vertical 1. The 3” concentric termination kit must be purchased separately. Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 2.
GWC gas-fired water boiler — Boiler Manual DIRECT VENT — Vertical with 3” concentric (continued) Mount concentric termination 1. Mount the termination as shown in Figure 53, page 44. 2. Support the concentric vent/air termination at the roof penetration as shown in Figure 53. • The supports/bracing used must support the termination assembly to prevent vertical slippage or sideways movement.
GWC gas-fired water boiler — Boiler Manual Concentric termination assembly Figure 54 3” PVC concentric termination assembly — DO NOT attach the rain cap until the termination has been inserted through the roof or wall and all supports have been installed. (sidewall or vertical) Assembling concentric termination 1. See Figure 54, page 45 for the details of the termination assembly. 2. Prepare the bird screen (two bird screens are supplied with the boiler). Cut the bird screen to size if required.
GWC gas-fired water boiler — Boiler Manual Vent and air piping and boiler connections DIRECT EXHAUST & DIRECT VENT Figure 55 Boiler vent and air connections Follow termination instructions 1. Read and follow all instructions for the termination type used before proceeding with this page. Installing vent and air piping 1. Work from the boiler to vent or air termination. Do not exceed the lengths given in the previous pages for either the air or vent piping. a.
GWC gas-fired water boiler — Boiler Manual DIRECT EXHAUST — Boiler room air openings Combustion air provision Special considerations The GWC boiler can use inside air if no contaminants are present in the boiler space. (If contaminants are likely to be present, install the boiler as a direct vent appliance, using the appropriate vent instructions in this manual.) Tight construction ANSI Z223.
GWC gas-fired water boiler — Boiler Manual DIRECT EXHAUST — Boiler room air openings (cont.) Figure 56 MINIMUM combustion air openings for direct exhaust applications — ALL OPENING SIZES ARE FREE AREA The GWC boiler CANNOT be in the same space with other appliances if clearances around the GWC are less than the recommended service clearances shown in Figure 2, page 6.
GWC gas-fired water boiler — Boiler Manual DIRECT EXHAUST — Sidewall DO NOT sidewall vent DIRECT EXHAUST APPLICATIONS at altitudes Figure 57 Installation sequence — Direct exhaust sidewall above 5,500 feet. Sidewall venting is only allowed for DIRECT VENT applications (ducted combustion air) at altitudes above 5,500 feet. Allowable vent/air pipe materials & lengths Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 1.
GWC gas-fired water boiler — Boiler Manual DIRECT EXHAUST — Sidewall (continued) Where the vent penetrates an outside wall, the annular space around the penetration must be permanently sealed using approved materials to prevent entry of combustion products into the building. Figure 58 DIRECT EXHAUST — Sidewall — termination assembly and termination options — all parts by installer except where shown otherwise 1. Wall penetration: a.
GWC gas-fired water boiler — Boiler Manual DIRECT EXHAUST — Vertical Allowable vent/air pipe materials & lengths Figure 59 Installation sequence — Direct exhaust vertical Use only the vent materials and kits listed in Figure 40, page 33. Provide pipe adapters if specified. 1. Locate the termination such that the total air piping and vent piping from the boiler to the termination will not exceed the maximum length given in Figure 39, page 32. Determine termination location 1.
GWC gas-fired water boiler — Boiler Manual Gas piping Connecting gas supply piping Figure 60 Gas supply connection to GWC boiler gas manifold Do not connect gas supply to boiler or attempt to operate boiler unless the correct orifice plate has been verified or installed in accordance with page 8. Except where otherwise instructed in this manual, do not attempt to measure or adjust the outlet pressure setting of the gas valve.
GWC gas-fired water boiler — Boiler Manual Gas piping (continued) Natural Gas Figure 61 Pipe capacity for 0.60 specific gravity natural gas 1. Refer to Figure 61 for pipe length and diameter. Size gas supply piping for total flow to all connected appliances. For each GWC boiler, provide for the following gas flow (cfh = cubic feet per hour): Boiler model CFH natural gas GWC-070 70 GWC-105 105 GWC-140 140 GWC-175 175 2. Inlet pressure required at gas valve inlet: • maximum 13” w.c.
GWC gas-fired water boiler — Boiler Manual Wiring For your safety, turn off electrical power supply at service entrance panel before making any electrical connections to avoid possible electric shock hazard. Failure to do so can cause severe personal injury or death. Figure 62 Field wiring connections — service switch and thermostat (or end switch) provided by installer Installation must comply with: National Electrical Code and any other national, state, provincial or local codes or regulations.
GWC gas-fired water boiler — Boiler Manual Wiring (continued) Figure 64 Ladder wiring diagram Part number 550-142-056/0411 55
GWC gas-fired water boiler — Boiler Manual Wiring (continued) Figure 65 Schematic wiring diagram 56 Part number 550-142-056/0411
GWC gas-fired water boiler — Boiler Manual Start-up Eliminate all system leaks. Continual fresh makeup water will reduce boiler life. Minerals can build up in sections, reducing heat transfer, overheating cast iron, and causing section failure.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) Check for gas leaks Before starting the boiler, and during initial operation, use a leak detector or smell near the floor and around the boiler for gas odorant or any unusual odor. Remove boiler front door and smell interior of boiler enclosure. Do not proceed with startup if there is any indication of a gas leak. Repair any leak at once.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) 3. Inject all of the inhibitor supplied with the boiler. Allow time for the water to circulate and mix. Then check the inhibitor level. Add additional inhibitor if necessary. 5. Once the external thermostat circuit wiring is checked and corrected if necessary, reconnect the external thermostat circuit wires. Allow the boiler to cycle. Check/verify water chemistry Inspect/fill condensate system 1.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) Final checks before starting boiler Figure 68 Check for igniter glow by looking into observation port on front of blower housing ❏❏ Review the boiler sequence of operation in Figure 71, page 63. ❏❏ Verify that the boiler and system are full of water and all system components are correctly set for operation. ❏❏ High altitude locations (over 5,500 feet) — verify that the high altitude pressure switch is installed per page 10.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) 5. Position and zero manometer per manufacturer’s instructions. The manometer must have at least 6” of tubing above the fluid level or fluid may be drawn into the gas valve. Figure 69 Tools required for gas valve outlet pressure measurement If manometer fluid is drawn into gas valve body, gas valve must be replaced.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) Final checklist Use the checklist following to ensure boiler is operating correctly. Have the following been completed? ❏❏ Is proper orifice plate installed? Refer to page 8 to check size and fuel type. ❏❏ Test additional field-installed controls — If boiler has a low water cutoff, additional high limit or other controls, test for operation as outlined by manufacturer. Burner should be operating and should go off when controls are tested.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) Figure 71 Integrated boiler control (IBC) sequence of operation — status light indications STEPS Call for Heat? POWER TSTAT CIRC LIMIT PRESS SWITCH FLAME Timing (After Step 8, the cycle goes back to Step 1) 1. Standby • Waiting for call for heat NO — 2. Call for heat • Circulator on YES — 3. Limit circuit • Limit controls closed • Block switch contacts closed • Blower on YES — 4.
GWC gas-fired water boiler — Boiler Manual Start-up (continued) Figure 72 Operating instructions 64 Part number 550-142-056/0411
GWC gas-fired water boiler — Boiler Manual Annual start-up and general maintenance schedule Figure 73 Service and maintenance schedules Service technician Owner maintenance (see following pages for instructions) (see following pages for instructions) General: • Address reported problems, page 66. • Inspect boiler area, page 66. • Inspect boiler interior, page 66. • Check boiler area Daily • Check air openings • Check pressure gauge • Inspect condensate drain system, page 66.
GWC gas-fired water boiler — Boiler Manual Annual start-up Annual start-up only by qualified service technician The boiler should be inspected and started annually, at the beginning of the heating season, only by a qualified service technician. In addition, the maintenance and care of the boiler designated in Figure 73, page 65 and explained on the following pages must be performed to assure maximum boiler efficiency and reliability.
GWC gas-fired water boiler — Boiler Manual Annual start-up (continued) Inspect expansion tank 1. Expansion tanks provide space for water to move in and out as the heating system water expands due to temperature increase or contracts as the water cools. Tanks may be open, closed or diaphragm or bladder type. See page 13 of this manual for suggested location of expansion tanks and air eliminators. • Open-type — located above highest radiator or baseboard unit, usually in the attic or closet.
GWC gas-fired water boiler — Boiler Manual Annual start-up (continued) Inspect recuperator Figure 75 Blower motor 1. Follow the procedure on page 71 to inspect the recuperator and clean if necessary. Inspect temperature mixing system 1. Carefully check the temperature of the system return piping as it passes through the boiler jacket and on the return pipe inside the boiler jacket just before it enters the boiler sections.
GWC gas-fired water boiler — Boiler Manual Annual start-up (continued) Inspect boiler relief valve Figure 76 Relief valve 1. Inspect the relief valve (Figure 76) and lift the lever to verify flow as in the following warnings, excerpted from a relief valve manufacturer’s warning label. Before operating any relief valve, ensure that it is piped with its discharge in a safe area to avoid severe scald potential. Read page 12 before proceeding further.
GWC gas-fired water boiler — Boiler Manual Service & maintenance Cleaning boiler heating surfaces Figure 77 Blower housing removal procedure The service procedures in this manual must only be performed by a qualified boiler service technician. Failure to comply could result in severe personal injury, death or substantial property damage. The boiler contains ceramic fiber and fiberglass materials. Use care when handling these materials per instructions on page 103 of this manual.
GWC gas-fired water boiler — Boiler Manual Service & maintenance (continued) To clean the burner Figure 78 Recuperator access and cleaning The burner may contain ceramic fiber particles. Use care when handling these materials per instructions on page 103 of this manual. Failure to comply could result in severe personal injury. 1. Clean the burner ports with a soft brush. 2. Use compressed air to blow out any particulate if necessary. Use caution to avoid particulate being blown into the building.
GWC gas-fired water boiler — Boiler Manual Service & maintenance (continued) Removing/cleaning/re-installing the recuperator Figure 80 Recuperator flueway drain holes Disconnect the vent pipe from the recuperator 1. The vent pipe must be disconnected (at the in-line flue drain, item A in Figure 7, page 9). 2. If the vent piping can be moved enough, loosen the flue pipe clamp on the in-line flue drain. Then lift the flue pipe up and move aside slightly. 3.
GWC gas-fired water boiler — Boiler Manual Troubleshooting VERIFY PROPER OPERATION AFTER SERVICING. Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Figure 81 Connecting a manometer to check air pressure switch. DO NOT use this arrangement to check gas valve Never jumper (bypass) any device except for momentary testing as outlined in Troubleshooting charts. Severe personal injury, death or substantial property damage can result.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Igniter Figure 82 Igniter Wait several minutes until igniter cools down before attempting replacement. Failure to do so will cause severe personal injury. 1. Disconnect igniter (Figure 82) from igniter wiring harness and remove igniter before removing from blower assembly. 2. Replace igniter gasket if original gasket is frayed or damaged OR if room-temperature resistance across igniter is not between 40 and 95 ohms. 3.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) c. Immediately disconnect the return temperature sensor plug from the IBC. d. Measure the resistance of the sensor. Write down the result. e. Let the sensor cool to room temperature and measure the resistance again. Write down the result. f. Compare the sensor resistances at both temperatures to the closest temperatures in Figure 87. g. If the measured values are within 10% of the values listed, the sensor is good.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Figure 89 IBC harness plug receptacle and indicator light locations 76 Part number 550-142-056/0411
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Figure 90 Common causes and possible corrections, part 1 Symptom Common Causes Possible Corrections Rapid cycling — boiler turns on and off frequently Thermostat installed where drafts or heat affect reading Locate thermostat on inner wall away from heat sources or cool drafts. Heat anticipator in thermostat adjusted incorrectly Adjust thermostat per manufacturer’s instructions.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Figure 91 Common causes and possible corrections, part 2 Symptom Common Causes Possible Corrections Popping or percolating noise heard in boiler Mineral deposits in sections due to constant use of makeup water Call qualified service technician to delime boiler, if necessary. In some cases, deposits will be too heavy to remove with de-liming procedures.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Troubleshooting POWER light status CHART 1 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. Is POWER light off? No Yes • Make sure service switch or circuit breaker is on or fuses are good. • Remove 120 VAC IN plug (Figure 89, page 76, Item 1) on IBC.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) TSTAT CIRC & POWER lights flashing CHART 2 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. Is return water temperature sensor clamped securely to the return pipe in the boiler? Yes • Attach sensor to pipe with clamp provided.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) LIMIT & POWER lights flashing CHART 3 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. • This is a LOCKOUT condition.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) PRESS SWITCH & POWER lights flashing CHART 4 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. • Reset boiler control by turning off power at service switch or turning down thermostat for at least 45 seconds. • Thermostat should call for heat and appropriate zone valves open.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) FLAME & POWER lights flashing CHART 5 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. Are manual main shutoff valve and gas valve turned on? No • Open manual gas valve.` • Restart boiler, following Operating instructions on boiler (see Figure 72, page 64).
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) TSTAT CIRC light flashing and POWER light on steady CHART 6 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. • This is NOT a lockout mode.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) LIMIT light flashing and POWER light on steady CHART 7 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. • This is NOT a lockout mode. The IBC should only be signaling that the water temperature sensor is either shorted or there is an open circuit across the sensor terminals.
GWC gas-fired water boiler — Boiler Manual Troubleshooting (continued) Insufficient heat or no heat to system (POWER light on steady) CHART 8 Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow instructions could result in severe personal injury, death or substantial property damage. • Has it been at least 5 minutes since setting thermostat to call for heat? If not, wait 5 minutes.
GWC gas-fired water boiler — Boiler Manual Replacement parts Figure 92 Miscellaneous parts Description Model WilliamsonThermoflo part number Vent termination plate for 3" AL29-4C or 3" PVC pipes (plate includes knockouts to provide larger holes needed for PVC) All 452-100-163WT Vent Termination Bird Screen 3" PVC (1 pc) All 383-500-105WT Termination bag assembly (includes two 2-hole sidewall termination plates and two bird screens, mounting screws and plastic anchors) All 542-200-314WT 3" PVC
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 93 Section assembly Item number Model Williamson-Thermoflo part number 1 Block assembly, includes: Front section, intermediate section, back section, square cut seals — 2”, silicone sealant, tie rods, tie rod nuts, tie rod washers, blower flange gasket, igniter, igniter gasket, screws, lock washers, studs, nuts 070 105 140 175 322-200-304WT 322-200-305WT 322-200-306WT 322-200-307WT 2 Front section replacement kit, inc
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 94 Section assembly Part number 550-142-056/0411 89
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 95 Jacket assembly Item number 90 Description Model Williamson-Thermoflo part number 070 and 105 140 and 175 382-200-700WT 382-200-701WT All 382-200-702WT 1 Jacket panel, top 2 Jacket panel, front 3 Jacket panel, left side, front 070 and 105 140 and 175 382-200-703WT 382-200-704WT 4 Jacket panel, left side, rear 070 and 105 140 and 175 382-200-705WT 382-200-706WT 5 Jacket panel, right side 070 and 105 1
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 96 Jacket assembly Part number 550-142-056/0411 91
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 97 Blower assembly Item number Description 1 Burner replacement kit, includes burner, blower flange gasket, igniter, igniter screws, igniter washers, igniter gasket 2 3 — 4 Blower flange gasket Air pressure switch (0 to 5,500 feet elevation) Air pressure switch (5,500 to 10,000 feet elevation) Blower motor replacement kit, includes blower motor, motor mounting grommets, screws, lock nuts and 9" Allen wrench Blower housin
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 98 Blower assembly Part number 550-142-056/0411 93
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 99 Trim assembly Item number 94 Description WilliamsonThermoflo part number 1 System circulator, Taco 007 511-405-113WT 2 Bypass circulator, Taco 007 511-405-113WT 3 Circulator gasket, Taco 110-339 590-317-543WT 4 Manifold, casting/circulator kit, includes water manifold, circulator gasket (Taco 110-339) (2), square cut seal (manifold to casting) 382-200-720WT 5 Return manifold, recuperator/circulator kit,
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 100 Trim assembly Part number 550-142-056/0411 95
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 101 Interior panel Item number 96 Description Williamson-Thermoflo part number 1 Interior panel see Figure 95, page 90, item 8 2 Integrated boiler control assembly, includes IBC and screws 382-200-448WT 3 Transformer 511-842-370WT 4 Air pressure switch 5 Wiring harness, IBC to junction box (not shown) 591-391-963WT 6 Wiring harness, IBC to hot surface ignitor (not shown) 591-391-819WT 7 Wiring harness,
GWC gas-fired water boiler — Boiler Manual Replacement parts (continued) Figure 102 Interior panel Part number 550-142-056/0411 97
GWC gas-fired water boiler — Boiler Manual Dimensions and ratings Figure 103 Dimension drawing (see Figure 104, page 99 for dimensional table) Item number 98 Description 1 1” NPT Supply 2 1” NPT Return 3 Combination pressure-temperature gauge, 2 ½” short shank 4 ¾” NPT Relief valve outlet 5 Plug dome, 2” black 6 Junction box 7 Inlet air fitting, 3" PVC 8 Flue outlet, 3" PVC 9 ½” Condensate drain 10 ½” NPT Gas supply connection (provided by others) 11 Drip leg (provided by other
GWC gas-fired water boiler — Boiler Manual Dimensions and ratings (continued) Figure 104 Boiler dimensional and physical data (see Figure 103, page 98) Boiler model Supply Return Length L Gas connection size (Note 1) Electrical service required Boiler water content Approx. shipping weight (includes the internal circulators) (inches NPT male) (inches NPT female) (inches) (inches NPT female) (amperes) (gallons) (pounds) GWC-070 1 1 30¾ ½ 15 3.8 313 GWC-105 1 1 30¾ ½ 15 4.
GWC gas-fired water boiler — Boiler Manual Dimensions and ratings (continued) Figure 106 Multiple GWC boilers — ratings and engineering data — maintain the clearances shown on pages 6 and 7 — see Figure 28, page 23 and Figure 29, page 23 for layout options Boilers in system Model GWC 070 105 140 175 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 8 8 8 8 Total CSA input DOE Heating capacity Boiler H.P.
GWC gas-fired water boiler — Boiler Manual Dimensions and ratings (continued) Figure 107 Engineering data — see page 99 for additional technical information Water flow rate per boiler Boiler Model Vent/air pipe size — Provide a separate vent for each boiler GPM @ 20°F rise GPM @ 40°F rise Note 1 GWC-070 6.5 3.3 3” GWC-105 9.7 4.9 3” GWC-140 13.0 6.5 3” GWC-175 16.1 8.1 3” Note 1 All GWC installations require a separate vent pipe and termination for each boiler.
GWC gas-fired water boiler — Boiler Manual NOTES 102 Part number 550-142-056/0411
GWC gas-fired water boiler — Boiler Manual Handling ceramic fiber and fiberglass materials HANDLING CERAMIC FIBER MATERIALS REMOVAL OR INSTALLATION OF FIBERGLASS WOOL Ceramic fibers can be converted to cristobalite in very high temperature applications. The International Agency for Research on Cancer (IARC) has concluded, “Crystalline silica inhaled in the form of quartz or cristobalite from occupational sources is carcinogenic to humans (Group 1).
GWC gas-fired water boiler — Boiler Manual Installation and service certificate Boiler model __________________ Series __________ CP number ___________ Date installed _______________ Measured Btuh input ____________ Installation instructions have been followed. Check-out sequence has been performed. Above information is certified to be correct. Information received and left with owner/maintenance person.
