D E S I G N E D T O L E A D MWC Series Mid Efficiency Gas-Fired Hot Water Direct Vent Condensing Boilers Installation Instructions These instructions must be affixed on or adjacent to the boiler. Models: • MWC116ENT • MWC116ELT • MWC116ENL • MWC116ELL Warning: Improper installation, adjustment, alteration, service or maintenance can cause property damage, injury, or loss of life. For assistance or additional information, consult a qualified installer, service agency or the gas supplier.
Table of Contents I. Product Description 2 II. Specifications 4 III. Before Installing 5 IV. Locating The Boiler 5 V. Mounting The Boiler 7 VI. Air For Ventilation 10 VII. Venting 12 A. Vent System Design 12 B. Removing An Existing Boiler From Common Chimney 19 C. Assembly of Crown 60/100 Concentric Venting 20 D. Assembly of Crown 80/125 Concentric Venting 24 E. Condensate Trap and Drain Line 33 VIII. Gas Piping 34 IX. System Piping 36 X. Domestic Water Piping 43 XI. Wiring 46 XII.
I Product Description The MWC Series are gas fired condensing boilers designed for use in forced hot water heating systems requiring supply water temperatures of 176F or less and return water temperatures greater than 86F. The primary heat exchanger is a copper water tube design. Additional heat is extracted from the flue gas in a stainless steel secondary heat exchanger located down stream of the inducer. These boilers include a built in circulator, expansion tank, and automatic air vent.
Figure 1.
II Specifications Figure 2.1: General Configuration Table 2.2: Ratings MINIMUM INPUT (BTU/ hr) MODEL* MAX. APPLICATION INPUT (BTU/hr) HEATING DHW Output (GPM) DHW D.O.E. HEATING CAPY. (BTU/hr) IBR NET RATING (BTU/hr) AFUE (%) 77F Rise 90F Rise MWC116E*T Combi 116,000 75,000 49,500 102,000 89,000 85.0 2.67 2.25 MWC116E*L Heat Only 116,000 75,000 N/A 102,000 89,000 85.0 N/A N/A * Insert suffix “N” for natural gas and “L” for propane.
III Before Installing 1) Safe, reliable operation of this boiler depends upon installation by a professional heating contractor in strict accordance with this manual and the authority having jurisdiction. • In the absence of an authority having jurisdiction, installation must be in accordance with this manual and the National Fuel Gas Code, ANSI Z223.1. /NFPA 54 and/or CAN/CSA B 149.1 Natural Gas and Propane Installation Code.
Clearance From Hot Water Pipes To Combustibles = 1” Figure 4.
V Mounting The Boiler CAUTION This boiler weighs approximately 110 pounds: • • Two people are required to safely lift this boiler onto the wall mounting hook. Make sure that wall mounting hook is anchored to a structure capable of supporting the weight of the boiler and attached piping when filled with water. Jurisdictions in areas subject to earthquakes may have special requirements for supporting this boiler. These local requirements take precedence over the requirements shown below.
Figure 5.
Figure 5.
VI Air for Ventilation WARNING Outdoor combustion air must be piped to the air intake. Never pipe combustion air from areas containing contaminates such as areas where swimming pool chemicals are stored. Contaminated combustion air will damage the boiler and may cause property damage, personal injury or loss of life. Air for combustion and ventilation, of the National Flue Gas Code, ANSI Z223.1/NFPA 54 CAN/CSA B 149.
Figure 6.1: Boiler Installed In A Confined Space, Ventilation Air From Inside Step 2a (contd.) • • If the total volume of both the boiler room and the room to which the openings connect is less than 50 cubic feet per 1000 BTU/hr of total appliance input, install a pair of identical openings into a third room. Connect additional rooms with openings until the total volume of all rooms is at least 50 cubic feet per 1000 BTU/hr of input.
VII Venting WARNING Failure to vent this boiler in accordance with these instructions could cause flue gas to enter the building resulting in severe property damage, personal injury, or death: • • • Do not attempt to vent this boiler with galvanized, PVC, or any other vent components not listed in Table 7.3. Do not obtain combustion air from within the building. Do not install a barometric damper or drafthood on this boiler. CAUTION Moisture and ice may form on the surfaces around the vent termination.
2 (contd.) Example: A 60/100mm concentric vent system is planned for a horizontally vented MWC116 which has the following components: • • • • 60/100mm Elbow Adaptor (supplied with the boiler) 1 ft Straight Pipe 90 elbow Uncut Terminal Section (supplied with the boiler) The Vent Option #2 column in Table 7.1 describes a horizontal direct vent system using 60/100mm concentric vent pipe. From this column, we see that a MWC116 may have a vent length of up to 8ft10in.
Table 7.1: Summary Of Horizontal Venting Options VENT OPTION # CLASSIFICATION USED IN THIS MANUAL 1 HORIZONTAL CONCENTRIC 2 HORIZONTAL CONCENTRIC 3 HORIZONTAL CONCENTRIC ILLUSTRATED IN FIGURE 7.2 7.2 7.2 VENT PIPE PENETRATION THROUGH STRUCTURE WALL WALL WALL 60/100 mm CONCENTRIC 60/100 mm CONCENTRIC 80/125 mm CONCENTRIC 82mm Not Used MAX. VENT LENGTH 25in 8ft - 10in 27ft - 10in MIN.
Table 7.
Figure 7.4a: Location Of Vent Terminal Relative To Windows, Doors, Grade Figure 7.4b: Location Of Vent Terminal Relative To Meters And Forced Air Inlets Figure 7.
Table 7.5: Vent/ Air Intake Fitting Equivalent Length VENT FITTING EQUIVALENT LENGTH (ft) 60/100mm 90° CONCENTRIC ELBOW 4.5 60/100mm 45° CONCENTRIC ELBOW 4.0 80/125mm 90° CONCENTRIC ELBOW 8.5 80/125mm 90° SWEEP CONCENTRIC ELBOW 5.5 80/125mm 45° CONCENTRIC ELBOW 3.0 80/125mm 90° CONCENTRIC SUPPORT ELBOW 8.5 6) Permitted Terminals for Vertical Venting - Use Crown PN 230532 with the appropriate flashing (Table 7.
Figure 7.
B. Removing an Existing Boiler From a Common Chimney Read this only if the MWC boiler is replacing an existing boiler that is being removed from a common chimney. This section does not apply to the installation of a MWC boiler. In some cases, when an existing boiler is removed from a common chimney, the common venting system may be too large for the remaining appliances.
C. Assembly of Crown 60/100mm Concentric Venting (IMPORTANT - Skip to Section D for 80/125mm Concentric Vent Assembly) WARNING Failure to follow the instructions could result in flue gas leakage into the combustion air or indoor air, resulting in unsafe or unreliable operation. • Do not lubricate concentric gaskets with anything other than water. • Do not attempt to cut any piping except as permitted in this section. When cutting these sections, make sure all cuts are square and allow for proper insertion.
FIGURE 7.20: INSTALLATION OF 60/100 ADAPTORS ON BOILER FIGURE 7.
4) If additional pieces of pipe are used, install them starting at the boiler elbow. Support each section of straight pipe at its female end. 5) Use locking bands provided to join adjacent sections of non-cuttable pipe as well as fittings. The male end of the terminal section and other cuttable sections must be held to the female end of the adjoining pipe with at least three #10 x 1/2” sheet metal screws. Drill a 1/8 hole through both outer pipes to start this screw.
Figure 7.24: Preparing 60/100mm Terminal Section For Installation In The Wall Figure 7.
D. Assembly of Crown 80/125mm Concentric Venting (IMPORTANT - See Section C for 60/100mm Concentric Vent Assembly) WARNING Failure to follow the instructions could result in flue gas leakage into the combustion air or indoor air, resulting in unsafe or unreliable operation. • Do not lubricate concentric gaskets with anything other than water. • Do not attempt to cut any piping except as permitted in this section. When cutting these sections, make sure all cuts are square and allow for proper insertion.
2) Installation of the MWC116 with 80/125mm venting requires the use of the 80/125mm appliance adaptor (Crown PN 340523). This adaptor is installed on top of the boiler as shown in Figure 7.30. For vent options 3 and 5, sandwich the 82mm air inlet orifice between the boiler and the adaptor as shown.
3) (contd.) To cut the straight sections listed above refer to Figure 7.32 and the following instructions: a) Determine the required length of the outer pipe. When doing this allow an additional 1” of length for insertion into the female end of the adjoining pipe. Mark the cut line on the outer pipe. b) Remove the plastic inner pipe by pulling it out from the female end. c) Cut the OUTER PIPE ONLY at the point marked in Step (a) using aviation shears, a hacksaw, or an abrasive wheel cutter.
Figure 7.33a: Joining Cuttable Pipe Figure 7.
5) 80/125mm Horizontal Terminal Installation a) Cut a 5-1/2” diameter hole through the exterior wall at the planned location of the horizontal terminal. b) Measure distance “L” from the outside surface of the exterior wall to the end of the last fitting as shown in Figure 7.34a. c) Add 1-1/4” to distance “L”. Carefully mark this length on the pipe as shown in Figure 7.34b. d) Remove the inner pipe from the terminal, by gently pulling on it from the male end. Set aside.
Figure 7.34c: Cutting Inner Pipe Of 80/125mm Horizontal Terminal Figure 7.
6) Vertical Terminal Installation - In addition to the vertical terminal, either a Flat Roof Flashing (PN 230533) or Sloped Roof Flashing (PN 230535) is required for this installation. a) Determine the center line of the terminal location on the roof. If the roof is flat, cut a 5-1/2” diameter hole for the terminal. If the roof is sloped, cut a hole large enough for the terminal to pass through the roof while remaining plumb.
Figure 7.35b: Cutting Vertical Terminal Figure 7.
WARNING • • Do not attempt to construct a vertical vent system inside a chimney that is used to vent a fireplace or other appliances. Do not attempt to construct a vertical vent system inside a chimney flue adjacent to another flue used by a fireplace or other appliances. Figure 7.
E. Condensate Trap and Drain Line All condensate which forms in the boiler or vent system leaves the boiler through the condensate trap. This trap allows condensate to drain while retaining flue gases in the boiler. This boiler is supplied with a length of drain hose already attached. Route this hose to a drain or other suitable location to dispose of the condensate.
VIII Gas Piping Gas piping to the boiler must be sized to deliver adequate gas for the boiler to fire at the nameplate input at an inlet pressure between the minimum and maximum values shown on the rating plate. For more information on gas line sizing, consult the utility or the National Fuel Gas Code ANSI Z223.1 /NFPA 54 and/or CAN/CSA B 149.1 Natural Gas and Propane Installation Code. The gas line is connected to the boiler using the 3/4” NPT female connection in the tailpiece shown in Figure 8.1.
Figure 8.
IX System Piping CAUTION • • • • • Install boiler so that the gas ignition system components are protected from water (dripping, spraying, rain, etc) during appliance operation and service (circulator replacement, etc). Operation of this boiler with continuous return temperatures below 86F can cause severe heat exchanger corrosion damage. Operation of this boiler in a system having frequent additions of make-up water can cause severe heat exchanger damage.
Figure 9.1: Basic Piping CAUTION Failure to install the throttling valve or flow restrictor described on the boiler supply could result in unreliable boiler operation 4) Expansion Tank (Included & Required) – This boiler is equipped with a built in expansion tank. This tank is suitable for use on systems having a water content of up to 40.6 Gal. This tank is pressurized to approximately 14.7 psi. 5) On systems having water content in excess of 40.6 gallons, a second expansion tank must be provided.
Figure 9.2: Circulator Performance Curve (Adjusted For Pressure Drop Through Boiler) B. Boiler Connections Boiler supply and return connections are located on the bottom of the boiler as shown in Figure 9.4. Copper 3/4” tail pieces are provided in the fitting bag along with gaskets. Sweat the first copper fittings to these tail pieces and then connect the tail pieces to the boiler using the gaskets provided. If required, install the flow restrictor in the supply as shown in Figure 9.4.
Figure 9.4: Supply And Return Tailpiece Installation C. Piping for Special Situations Certain types of heating systems have additional requirements. Some examples follow: 1) Primary-Secondary Piping – Primary-secondary piping is required when circulator zoning is used or when the system flow rate must be greater than 5.5 GPM. In these cases, the piping shown in Figure 9.5 is used so that the flow through the system is completely independent of the flow through the boiler.
Figure 9.5: Primary-Secondary Piping Figure 9.
Figure 9.
Figure 9.
X. Domestic Water Piping CAUTION If the MWC is connected to a water supply having a hardness in excess of 200PPM, scale may prematurely form in the DHW heat exchanger, significantly shortening its life. If necessary, soften the water upstream of the cold water connection to the MWC. If the MWC is equipped for domestic hot water (DHW) production, connect the domestic hot water piping as shown in Figure 10.1. Connections to the boiler are made with 1/2” copper tail pieces as shown in Figure 10.2.
Figure 10.1: DHW Piping Figure 10.
Figure 10.
XI Wiring WARNING All wiring and grounding must be done in accordance with the authority having jurisdiction or, in the absence of such requirements, with the National Electrical Code (ANSI/NFPA 70), and / or, the Canadian Electrical Code Part I ,CSA C22.1,Electrical Code. 1) All electrical connections are line voltage (120 VAC) and are located under the cover on the cover on the top of the control box (Fig 11.1).
Figure 11.1: Accessing Electrical Connections Field Supplied J-Box End Boiler End Figure 11.
Figure 11.3: Location of Terminal Blocks and 7/8 Hole for Whip Figure 11.4: Electrical Connections Inside Control Box.
Figure 11.5: Field Wiring - 120VAC Thermostat Figure 11.
Flue thermostat or Safety thermostat wh Electric supply terminal block Fan Air pressure switch NC Ignition electrodes Flame detection electrode NO rd External controls terminal block L N bn M 3 2 1 COM ~ bn gnye bk bu wh rd bu wh gy gnye bu ye wh bu bk gy rd gnye rd bu bn gnye gnye ye bk wh gy bu rd rd wh or bk rd wh gy bk bk rd bu bu bu bk bk gy gy bn gnyebu gy bu wh rd rd rd gy wh bu bk bk rd rd bu wh bk rd 3 1 M rd bu COM wh t rd 2 ~ bk M bu **D
XII Start-up and Checkout NOTE Safe lighting and other performance criteria were met with the gas train assembly provided on the boiler when the boiler underwent the tests specified in Z21.13. WARNING Never attempt to fill a hot empty boiler Use the following procedure for initial start-up of the boiler: 1) If not already done, flush the system to remove sediment and debris. This should be done with the boiler isolated from the system.
Shaft Screw Cover Figure 12.2: Location of Circulator Shaft Cover WARNING • • Never use a flame to check for gas leaks. Make sure that the area around the boiler is clear and free from combustible materials, gasoline and other flammable vapors and liquids CAUTION Leaks in the hydronic system can result in the addition of excessive amounts of makeup water. This can cause severe damage to the boiler’s heat exchanger from corrosion or calcium deposits. Repair any leaks in the system immediately.
Heating System Knob Lamp 1 Lamp 2 Lamp 3 DHW Thermostat (Combi Only) Flame Reset Button Flame Lockout Lamp Figure 12.3: Control Panel • The burner may not light on the first try. The most likely cause of this problem on a new installation is a gas line that has not been completely purged. Other possibilities include inadequate inlet gas pressure or a boiler that is configured for the wrong fuel. If the boiler does not light on the first try, it will go into a lockout condition.
b) Loosen the screw in the gas inlet tap on the gas valve and connect a manometer (see Figure 12.6). c) Make sure the boiler is at high fire. To do this: • • On heat only boilers, make sure that the heating system knob is rotated fully clockwise and that the supply temperature is less than 150F during the entire conduct of this test.
Figure 12.5: Inner Cover Removal Manifold Pressure Tap Inlet Pressure Tap Modulation Leads Figure 12.6: Gas Pressure Taps High Fire Adjustment (Outer Brass Nut) Low Fire Adjustment (Inner Hex Shaft) Figure 12.
MWC Series Lighting and Operating Instructions FOR YOUR SAFETY READ BEFORE OPERATING WARNING: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life. --- If you cannot reach your gas supplier, call the fire department. A This appliance does not have a pilot. It is equipped with an ignition device which automatically lights the burner. Do not try to light the burner by hand.
9) Remove the monometer and make sure that the inlet and manifold pressure tap screws are closed 10) Check the entire gas train for leaks. Fix any leaks found immediately. 11) Run the gas valve safety shut-down test. With the boiler firing, close the gas cock upstream of the boiler. The gas valve should close as soon as loss of flame is detected (within a few seconds of closing the gas cock). The boiler should then make one attempt to relight before going into a hard lockout.
XIII Operation Heating System Knob Lamp 1 Lamp 2 Lamp 3 DHW Thermostat (Combi Only) Flame Reset Button Flame Lockout Lamp Figure 13.1: Control Panel Figure 13.1 shows the control panel for the MWC boiler. The purpose of the adjustments and lamps on this panel are as follows: 1) Lamps 1, 2, 3 - These lamps show the status of the boiler by lighting and/or flashing in various combinations. Table 13.4 shows lamp codes that will be seen during normal operation.
Target Supply Temp = 100F Off Summer Operation Target Supply Temp = 178F Figure 13.2: Heating System Knob NOTE Since a room thermostat will almost always be used to initiate a call for heat (either directly or through zone controls), it is generally recommended that the Heating System Knob be left at the appropriate Target Supply Temperature year round. 95F Target DHW Temp 131F Target DHW Temp Figure 13.
Sequence of Operation (Also Refer to Figures 9.7, 9.8, 10.3, 11.7) 1) Upon a call for heat from the room thermostat, the circulator is started. 2) If the differential pressure switch connected between the supply and return sees a pressure in excess of 5.1 ft w.c., it closes, allowing the start sequence to continue. If the switch does not see 5.1ft w.c. after 180seconds, the boiler goes into lockout. 3) If the common and normally closed contacts on the air pressure switch are made, the inducer starts.
Table 13.4: Flash Codes During Normal Operation (See Part XV for Error Codes) Lamp Number Meaning 1 2 3 (Short pulse every 4 seconds): Heating System Knob in “Off” position. Boiler will not respond to call for heat or DHW. Frost protection and pump/valve exercise function still active (1 second pulse every 2 seconds): Heating System Knob set to target supply temperature. Boiler will respond to a call for heat.
XIV. Service and Maintenance IMPORTANT Warranty does not cover boiler damage or malfunction if the following steps are not performed at the intervals specified. 1) Continuously: a) Keep the area around the boiler free from combustible materials, gasoline and other flammable vapors and liquids. b) Keep the area around the combustion air inlet terminal free from contaminates . c) Keep the boiler room ventilation openings open and unobstructed.
Figure 14.1: Removing Combustion Chamber Cover WARNING Soot deposits in the flue passages are a sign that the boiler may be operating at high carbon monoxide (CO) levels. After cleaning the boiler of soot deposits, check the CO level in the flue gas to insure that the boiler is operating properly. If it is necessary to check CO, use a combustion analyzer, or other instrument which is designed to measure CO in flue gas (see Start-up section).
Service Notes 1) Orifice Size – Sea level orifice sizes are: Natural Gas – 1.30 mm LP Gas – 0.85 mm Consult your Crown representative for correct orifice sizes for use at altitudes above 2000 ft. Orifice for this boiler cannot be drilled in the field. 2) Operating the Boiler with Inner Cover Removed – For inspection and troubleshooting purposes, this boiler may be started and run with the Inner Cover (Figure 12.5) removed.
Spring Clip Condensate Trap Figure 14.3: Condensate Trap Removal Figure 14.
XV. Troubleshooting WARNING Turn off power to boiler before replacing fuses or working on wiring. Table 15.1: No Error Code Displayed CONDITION POSSIBLE CAUSES Boiler does not run, no lights are on or flashing • No 120VAC Power at boiler. Check breaker and wiring between breaker panel and boiler • Fuse on main PCB is blown (Figure 15.2). Check for short in boiler wiring, then replace with an idenitcal 4.0A fuse. Lamp 1 flashes every two seconds, but boiler does not respond to a call for heat.
Table 15.3: Error Codes Lamp Number 1 2 3 Flame L.O. Lamp Meaning Differential Water Pressure Switch Failed to Close After 180s Failure to Establish Flame or Blocked Condensate Trap or Reversed Line Voltage Polarity (Note: LED #2 will not illuminate until error has been present for 4 minutes) Corrective Action Reset the boiler by turning the Heating System Knob to “0” for a few seconds, then returning it to its original position.
Figure 15.4 Flow Chart for Isolating Limit and APS Errors (See Table 15.3) Push reset button on Flue Temp Limit (Fig 14.4) Reset Boiler Reset Boiler Does Boiler Start? Push reset button on Supply Temp Limit (Fig 14.4) N Does Boiler Start? Y N Y Flue Temp Limit was open and will probably open again. Look for: Supply Temp Limit was open and will probably open again.
XVI Parts The following parts may be obtained from any Crown distributor. To find the closest Crown distributor, consult the area Crown representative or the factory at: Crown Boiler Co. Customer Service P.O. Box 14818 Philadelphia, PA 19134 www.crownboiler.com C.h. return group and d.h.w.
C.h.
C.h. flow and return groups (Model c.h.
Pump and main circuit assembly (Model combi) 37 63 64 7 38 62 38 39 40 39 44 41 42 61 45 48 60 65 46 58 41 40 49 50 43 47 44 59 41 58 7 3 57 7 51 56 53 55 54 72 52
Pump and main circuit assembly (Model c.h.
Gas assembly 78 41 66 7 67 77 68 76 7 69 70 73 75 71 72 7 74 74
Connection pipes 7 10* 7 10* 7 79 80* 81 80* 79 * Not for model c.h.
Control panel and ignition device (Model combi) 72 97 82 72 72 83 96 72 95 94 72 53 93 84 85 92 91 77 90 89 88 87 76 86
Control panel and ignition device (Model c.h.
Wiring (Model combi) 98 113 99 100 101 105 113 113 99 102 77 103 109 104 100 107 105 71 106 107 108 108 112 101 102 103 111 108 110 78 109
Wiring (Model c.h.
Fan, combustion chamber and case panels 114 140 140 141 115 139 138 116 77 77 142 137 117 72 143 136 118 144 135 119 133 120 132 134 131 121 77 130 122 129 77 122 123 77 77 121 77 128 127 126 80 125 124
Key no.
Key no.
Key no. Description Spare part code 93 Screw 3,5x16 mm self tap RPH BI1165 101 94 Electronic control - ignition p.c.b.
Key no. Description Spare part code 141 Flue thermostat BI1262 104 142 Twin flue cover plate BI1366 114 143 Gasket - Air intake twin kit BI1016 101 144 Air restrictor d. 45 mm BI1406 129 145 Return group (Model c.h. only) BI1171 107 146 By-pass pipe (Model c.h. only) BI1171 106 147 Flow group kit (Model c.h. only) BI1171 103 148 Safety valve connection pipe (Model c.h. only) BI1262 140 149 Main exchanger outlet pipe (Model c.h. only) BI1262 141 150 Control panel box (Model c.
2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as required in accordance with the above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified. 3. SIGNAGE. A metal or plastic identification plate shall be permanently mounted to the exterior of the building at a minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment.
11/07 2008 Manufacturer of Hydronic Heating Products P.O. Box 14818 3633 I. Street Philadelphia, PA 19134 Tel: (215) 535-8900 • Fax: (215) 535-9736 • www.crownboiler.