TM Built tough with maximum efficiency MODELS DB/DW-720-1810 NATURAL GAS-FIRED COMMERCIAL CROSS FLOW COPPER BOILERS FOR HYDRONIC HEATING AND HOT WATER SUPPLY WITH ELECTRONIC INTERMITTENT PILOT IGNITION AND INSTALLATIONS • INSTALLATION • OPERATION • MAINTENANCE • LIMITED WARRANTY WARNING: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life.
CONTENTS Page Page FOREWORD ................................................................................ REPLACEMENT PARTS .............................................................. ROUGH-IN DIMENSIONS/CAPACITIES ...................................... Installation Clearances .............................................................. Levelling ................................................................................... FEATURES ...........................................................
CAUTION Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. "Verify proper operation after servicing." ROUGH-IN DIMENSIONS/ CAPACITIES Two inch clearance is allowable from combustible construction for hot water pipes. Sufficient clearance should be provided at one end of the boiler to permit access to heat exchanger tubes for cleaning. Maximum operating water supply pressure 160 psi. Gas supply pressure: 13.8" w.c. max., 5.5" w.c. min.
WARNING Your Dura-Max boiler is not designed to operate with a boiler inlet water temperature of less than 100°F (38°C). Colder inlet water temperatures will result in significant condensation developing on the heat exchanger. This situation can cause a corrosive environment for the heat exchanger, burners and venting resulting in premature damage, which could result in serious personal injury or death.
and pilot gases are cut off during the “OFF” cycle. Pilot gas ignition is proven by the pilot sensor. Main burner ignition will not occur if the pilot sensor does not first sense pilot ignition. FEATURES IMPORTANT Only qualified personnel shall perform the initial firing of the heater. At this time the user should not hesitate to ask the individual any questions regarding the operation and maintenance of the unit. Lighting and Operating instructions are included at the rear of this manual.
AUTOMATIC RESET HIGH TEMPERATURE LIMIT CONTROL The heater operation with above set points will be as follows: 1) When heater temperature rises to LO thermostat setting the main gas valve will close its second stage operator to drop input to approximately 50% of total input. 2) System conditions will determine if temperature rise at LO thermostat sensor location will continue to rise until shut-off by high limit or drop causing heater to go back to full input.
If the boiler is installed above the level of heating system terminal units, a low water cutoff device must be installed in the boiler outlet at the time of installation. INSTALLATION INSTRUCTIONS REQUIRED ABILITY INSTALLATION OR SERVICE OF THIS BOILER REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE REQUIRED. WARNING THE INLET/OUTLET WATER MANIFOLD ON YOUR A. O.
If the confined space is within a building of tight construction, air for combustion, ventilation, and draft hood dilution must be obtained from outdoors. When directly communicating with the outdoors or communicating with the outdoors through vertical ducts, two permanent openings, located in the aforementioned manner, shall be provided. Each opening shall have a free area of not less than one square inch per 4000 Btu/hr (551 mm2 per kw) of the total input of all appliances in the enclosure.
WARNING FAILURE TO CORRECT BACK DRAFTS MAY CAUSE AIR CONTAMINATION AND UNSAFE CONDITIONS. Vent connectors serving appliances vented by natural draft shall not be connected into any portion of mechanical draft systems operating under positive pressure. 3. CONNECTING BOILER TO A COMMON VENT Do not connect the boiler to a common vent or chimney with solid fuel burning equipment.
PURGING Gas line purging is required with new piping or systems in which air has entered. CAUTION PURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED IN THIS TYPE OF GAS SERVICE TO AVOID RISK OF FIRE OR EXPLOSION. PURGE DISCHARGE MUST NOT ENTER CONFINED AREAS OR SPACES WHERE IGNITION CAN OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF IGNITION MUST BE INACTIVATED OR REMOVED. BEFORE PLACING THE BOILER IN OPERATION, CHECK FOR GAS LEAKAGE.
Applications of the gravity factor converts the figures given in table 1 to capacities with another gas of different specific gravity. Such application is accomplished by multiplying the capacities given in table 1 by the multipliers shown in table 5.
IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED WITH THE APPLIANCE, MUST BE REPLACED, IT MUST BE REPLACED WITH TYPE 105°C WIRE OR ITS EQUIVALENT, EXCEPT FOR THE FLAME SENSOR AND IGNITION CABLE WHICH ARE 250°C. SERVICING WIRING AND/OR CONTROL CAUTION Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing.
FIGURE 8 The flow switch shall be mounted in the top opening of the reducing tee and provide adequate paddle length in the flow stream. For example in a 2" pipe installation use a 2" x 2" x 1" reducing tee. For 2" or 3" pipe use the paddle segments as supplied. For other pipe sizes (i.e. 2-1/2") trim the paddle to the proper pipe size, see fig. 8. If a standard tee is used, install a face or hex bushing in the top opening.
Thereafter, during the heating season, lubricate the three oil cups at least once every four months. Combination heating/cooling systems or water heating (Cer-temp) systems should be lubricated every four months year-round. all cases, that the water temperature be set for the lowest temperature which satisfies the user's hot water needs. This will also provide the most energy efficient operation of the water heater and minimize scale formation. Use 2 or 3 teaspoonfuls in bearing oil cups, fig.
A system bypass should be installed as shown in fig. 10 to prevent boiler circulation starvation when the system zones call for reduced flow. This bypass may also be used with multiple boilers manifolded for reverse-return flow. The system bypass would be installed from boiler outlet to suction side of pump. determine if boiler will shut down or if unit will return smoothly to full input.
NOTES: 1. BUILDING TEMPERATURE CONTROLS SUPPLY ELECTRIC POWER TO BUILDING CIRCULATOR. 2. MAIN FLOW SWITCH PROVES MAIN WATER FLOW BEFORE ENERGIZING, SEQUENCING AND RESETTING CONTROLS. 3. OUTDOOR THERMOSTAT REQUIRED IF BUILDING CONTROLS DO NOT PROVIDE AUTOMATIC SHUT-DOWN OF RESET CONTROLS DURING WARM WEATHER.
BYPASS BALANCING With systems where water temperature can be expected to drop appreciably due to long standby periods, or heavy draw down, a bypass pipe of at least 1" size with a balancing cock should be installed between the boiler inlet and outlet (see fig. 10). When the system first starts, the valve should be slowly opened until the condensing ceases. This adjustment remains at a permanent setting to establish required temperature rise across the boiler.
generator type boilers establish temperature rises. The deciding factor in choice of boiler temperature rise relates to the boiler inlet temperature. Boiler outlet, minus system temperature drop, is boiler inlet temperature. THE BOILER TEMPERATURE RISE SHOULD NOT RAISE THE OUTLET TEMPERATURE UP TO THE MAXIMUM 250°F (115°C) SETTING OF THE LIMIT CONTROL.
TABLE 8. NO. SUGGESTED ITEMS FOR INSTALLATION 1. SHORT PIPE NIPPLE AND PAIR OF BOILER LOOP TEES IN PIPING BETWEEN SYSTEM SUPPLY AND RETURN - ONE SET PER EACH BOILER BOILER PIPE LOOP (See Piping Sizing Data Table 3.) BOILER CIRCULATING PUMP (See Piping Sizing Data Table 3.) THERMOMETER PRESSURE GAUGE LOW WATER CUT-OFF (If Required By Local Code.) SAFETY FLOW SWITCH RELIEF VALVE (Furnished with Boiler) BOILER INLET - OUTLET SYSTEM SUPPLY TEMPERATURE THERMOMETER DRAIN OR BLOW-DOWN VALVE 2. 3. 4. 5. 6. 7.
USE ONY TYPE 105°C THERMOPLASTIC OR ITS EQUIVALENT IF ANY OF THE ORIGINAL WIRES AS SUPPLIED MUST BE REPLACED. BOILER CONVENTIONAL SYSTEM FIGURE 15 USE ONY TYPE 105°C THERMOPLASTIC OR ITS EQUIVALENT IF ANY OF THE ORIGINAL WIRES AS SUPPLIED MUST BE REPLACED.
DURA-MAX - SINGLE STAGE FIRING - UNITED STATES MODELS WITH PUMP.
DURA-MAX - DUAL STAGE FIRING - UNITED STATES MODELS WITH PUMP.
DURA-MAX - MODULATED FIRING - UNITED STATES MODELS WITH PUMP.
DURA-MAX - SINGLE STAGE FIRING - UNITED STATES & CANADIAN MODELS WITHOUT PUMP.
DURA-MAX - DUAL STAGE FIRING - UNITED STATES & CANADIAN MODELS WITHOUT PUMP.
DURA-MAX - MODULATED FIRING - UNITED STATES & CANADIAN MODELS WITHOUT PUMP.
Cer-Temp 80 Recovery Systems Where excessive heat exchanger condensation exists due to continued low water inlet temperatures, a bypass balance loop must be installed (see page 15). WATER LINE CONNECTIONS HARD WATER CONDITIONS HOT WATER SUPPLY APPLICATIONS This section provides detailed installation diagrams for typical methods of application for the unit using a Cer-Temp 80 Recovery System (for one temperature water).
ONE DURA-MAX (MODEL DW) COMMERCIAL BOILER WITH HORIZONTAL TANK CAUTION TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100°F (38°C) IMPORTANT SAFETY FLOW SWITCH AS SHOWN TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE. CAUTION PUMP MUST BE RATED FOR SYSTEM OPERATING TEMPERATURES AND PRESSURE. SEE TABLE 7 FOR GUIDE TO PIPE AND PUMP SIZING. INSTALL IN ACCORDANCE WITH ALL LOCAL CODES. SEE PAGE 31 FOR ADDITIONAL PIPING INFORMATION.
TWO DURA-MAX (MODEL DW) HOT WATER SUPPLY BOILERS WITH VERTICAL TANK CAUTION TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100°F (38°C) SEE PAGE 31 FOR ADDITIONAL PIPING INFORMATION. 29 Guide To Pipe and Pump Sizing Two (2) Boiler Systems Common Manifold Pipe Boiler Pipe Size Model Size "A" (Min.) "B" (Min.) and Pump 720, 840 2-1/2" NPT See Table 7 960-1810 3" NPT Pipe and pump capacities for two (2) boiler systems based on 100 equivalent feet (30 meters) heater to tank loop.
TWO DURA-MAX (MODEL DW) HOT WATER SUPPLY BOILERS WITH HORIZONTAL TANK CAUTION TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100°F (38°C) SEE PAGE 31 FOR ADDITIONAL PIPING INFORMATION. IMPORTANT THE INSTALLATION OF SAFETY FLOW SWITCHES AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE. NOTE: THERMOMETERS, RELIEF VALVES, CIRCULATORS, SAFETY FLOW SWITCHES AND TANK CONTROLS ARE AVAILABLE THROUGH A.O.SMITH.
MANIFOLDING OF MODEL TJV-120M & TJV-200M TANKS A.O. SMITH TJV-120M & TJV-200M TANKS WITH: PART NO. 170354 FOR TWO TANK MANIFOLD KIT PART NO. 170355 FOR THREE TANK MANIFOLD KIT NOTE: PIPE SIZES BETWEEN MANIFOLDS AND BOILER(S) TO BE SELECTED FROM THE CER-TEMP 80 DIAGRAM FOR THE HEATER MODEL TO BE INSTALLED. ALL PIPING FROM TEES TO BE EQUIDISTANT TO TANKS. INSTALL IN ACCORDANCE WITH ALL LOCAL CODES. * PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.
TWO HORIZONTAL TANK INSTALLATION THREE HORIZONTAL TANK INSTALLATION FIGURE 25 START-UP AND OPERATING INSTRUCTIONS WARNING After placing boiler into operation, the ignition system safety shutoff device must be tested by the following test method. 1. Reset Manual High Temperature Safety Limit Control (High Limit) to the lowest setting. (See figures 3 or 4, pages 5 or 6). 2. Reset System Controller to maximum setting, causing a call for heat and allowing unit to run until High Limit trips. 3.
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." A. B. C. D. WARNING: HOT WATER CAN PRODUCE 3rd DEGREE BURNS IN 6 SECONDS AT 140° F. (60° C). IN CASE OF POWER FAILURE DO NOT ATTEMPT TO OPERATE BOILER. IMPROPER INSTALLATION, ADJUSTMENT, ALTERATION, SERVICE OR MAINTENANCE CAN CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
INTERNAL CONTAMINANTS The system must be internally cleaned and flushed after a new or replacement unit has been installed to remove contaminants that may have accumulated during installation. This is doubly important when a replacement unit is installed into an existing system where Stop Leak or other boiler additives have been used. All systems should be completely flushed with a grease removing solution to assure trouble-free operation.
1. Remove main burners from unit. 2. Check that burner venturi and ports are free of foreign matter. 3. Clean burners with bristle brush and/or vacuum cleaner 3/4" DO NOT distort burner ports or pilot location. 4. Reinstall burners in unit. Making sure front and rear of burners are installed correctly in burner support brackets. Also check for good flow of combustion and ventilating air to the unit. Maintain a clear area around the boiler at all times.
CHECKING HONEYWELL S8600H OR S8610M (NAT. GAS) INTERMITTENT IGNITION CONTROLS NO SPARK AT PILOT BURNER NO Replace ignition module Is voltage (24 Vac) across the 24 V terrminals on module during “call for heat”? YES Is voltage (24 Vac) across the PV & MV/PV terminals on “call for heat”? NO NOTE: S8610M will automatically reset every five (5) minutes. For S8600H pilot valve will be de-energized if module goes into lockout condition.
SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT Ensure all manual shutoff valves are fully open; All filters are clean; All gas connections are gas tight; Pilot tubing is not damaged, obstructed or kinked; and pilot orifice is unclogged. Check for air in gas line, purge (bleed) line if necessary. NO Attach wires firmly. Are the wires securely attached to the pilot operator on the gas control and to the PV & MV/PV terminals on the ignition module? YES NO Replace gas valve.
PILOT BURNER LIGHTS BUT MAIN BURNER DOES NOT LIGHT Correct the situation by consulting the installation or user’s manual on how to adjust pilot flame. NO Does the pilot flame cover 3/8° to 1/2" (10 mm to 12 mm) of igniter/sensor rod? YES Replace ignition module. NO NO Is voltage (24 Vac) across terminals MV and MV/PV? Does spark stay on for more than 30 seconds after the pilot is “proven” (lit)? YES Attach wires firmly.
GENERAL MAINTENANCE These boilers are designed to give many years of efficient and satisfactory service when properly operated and maintained. To assure continued good performance, the following recommendations are made. The area around the unit should be kept clean and free from lint and debris. Sweeping the floor around the boiler should be done carefully. This will reduce the dust and dirt which may enter the burner and pilot air passages, causing improper combustion and sooting.
The time between cleaning will vary from two to six months depending upon water conditions and usage. A change of approximately 5°F in the normal temperature rise through the boiler is usually an indication that scale should be removed. For long life, copper or brass is recommended for all valves, pipe and fittings used between gate valves “A” and “B” and the boiler, see fig. 29. 12. Close drain cock and open valves "A" and "B". Purge system of air. Restore electric and gas supply.
DURA-MAX LIMITED WARRANTY A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this hydronic boiler: 1. If within TEN years after initial installation of the boiler, the heat exchanger shall prove upon examination by the warrantor to be defective in material or workmanship, the warrantor, at his option will exchange or repair such part or portion.
REPLACEMENT PARTS 5621 W. 115TH STREET, ALSIP, IL 60803 PHONE: 800-433-2545 FAX: 800-433-2515 www.hotwater.com E-Mail: parts@hotwater.