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S U F   S E R V I C E   H A N D B O O K

T R O U B L E S H O O T I N G

Technical Training Department

State Water Heaters

STC-077

22

Ashland City, Tennessee © 2004

ECO CHECK (CONTINUED)

STEP 5:

CHECK FOR 24 VAC BETWEEN PIN 1 ON CN3 PLUG AND GROUND.

Condition:

• Reconnect CN3 plug to control board.
• On/Off switch is on.

Insert one meter probe into the back of CN3 plug pin 1, check for 24 VAC between here and ground 
with CN3 plugged in and power on. (See illustration above for pin number locations.)

STEP 5

24 VAC FROM ECO 

IF…

THEN

24 VAC is not present

make sure water temperature in tank is below 160° F, press Set/Reset button on 
display panel, replace upper temperature/ECO probe if tank water temperature is 
below 160 and Step 4 has been performed and results were successful. 

24 VAC is present

continue to Step 6.

Summary of Contents for Utra-Force STC-077

Page 1: ...The Expert s Choice COMMERCIAL...

Page 2: ...Pre Service 18 120 VAC to Control 18 Transformer 19 20 ECO Check 21 22 Temperature Probe 23 Pressure Switch Continuity 24 Troubleshooting continued Blower 25 Pressure Switch Performance 26 27 120 VAC...

Page 3: ...problem not covered in this handbook please contact the State Technical Information Department at 1 800 365 0577 or your local State Represen tative for further assistance This handbook is intended f...

Page 4: ...nual The supply gas pressure is normally measured at the dirt leg or at the inlet gas pressure tap on the gas valve This reading must be measured with flowing gas The manifold gas pressure is measured...

Page 5: ...nch venting terminals provided must be used with the 4 inch venting by adding 4 x 3 reducing coupling at the venting terminals A reducing coupling is also needed immediately after the condensate elbow...

Page 6: ...then the proper cement must be used for all joints including joining the pipe to the Termination Tee PVC Material PVC Materials should use ASTM D 2564 Grade Cement CPVC Material should use ASTM F 493...

Page 7: ...lation manual for complete venting installation instructions This concentric vent termination kit may be used with 3 or 4 in diameter pipe systems When con necting to a 4 in diameter pipe system a 3 x...

Page 8: ...s the exterior clearances for these SUF units when installed as direct vent heaters N O T E 24 inches between inlet and outlet is a MINIMUM Greater distance is recommended In colder climates increasin...

Page 9: ...nits are directly vented through a wall all intake vent terminals must be no lower than the highest exhaust vent terminal CAUTION DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE EX HAUST OR INTAKE W...

Page 10: ...also recommends an additional 2 5 cu ft of excess air This 12 5 cu ft minimum supply air per 1000 BTUH input applies to natural and propane gas mod els The National Fuel Code also specifies minimum m...

Page 11: ...ot less than 1 square inch per 4000 BTUH of the total input of all appliances within the enclosure The lower opening is primarily providing combustion air The upper opening is providing vent dilu tion...

Page 12: ...tal input of all appliances within the enclosure INSUFFICIENT MAKE UP AIR Backdraft Insufficient make up air is a major cause of combustion problems One common example is in a restaurant installation...

Page 13: ...r hydrofluoric acid and other corrosive by products Dust drawn in may build up on the blower or clog the main burner ports Also be certain to examine the exterior area around the air intake of a direc...

Page 14: ...3 STC 077 MULTIPLE UNIT WATER PIPING NOTES APPLY TO ALL SYSTEMS ADD GATE VALVES TO INLET AND OUTLET OF EACH UNIT FOR ISOLATION FLEXIBILITY LOCATE AT THE SAME POINT FROM TEE ADD THERMAL EXPANSION TANK...

Page 15: ...NSATE AND SODA POP The pH of the SUF con densate average 4 5 which is approximately 4 times less concentrated than the limit of 4 3 recom mended by the DMA Any water flow in the drain rapidly dilutes...

Page 16: ...S U F S E R V I C E H A N D B O O K O P E R A T I O N State Water Heaters Technical Training Department Ashland City Tennessee 2004 15 STC 077 OPERATION SEQUENCE OF OPERATION...

Page 17: ...ent Switch LED light on Blower while blower is running LED light on Air Pressure Switch while blower is running LED light on Control Status LED light on Gas Valve during ignition period and heating cy...

Page 18: ...U F S E R V I C E H A N D B O O K O P E R A T I O N State Water Heaters Technical Training Department Ashland City Tennessee 2004 17 STC 077 CIRCUT BOARDS DISPLAY CIRCUIT BOARD IGNITION CIRCUIT BOARD...

Page 19: ...minal white wire on plug STEP 1 120 VAC TO CONTROL BOARD IF THEN 120 VAC is not present check On Off switch turn switch on replace On Off switch if defective restore power to the water heater 120 VAC...

Page 20: ...isconnect CN4 plug from control board On Off switch is on Check for 120 VAC between pin 1 and 2 at CN4 on the control board as illustrated above Perform this test with the CN4 plug disconnected and th...

Page 21: ...AC AT TRANSFORMER CN4 PLUG ON CONTROL BOARD Condition CN4 is plugged into control board On Off switch is on Insert meter probes into back of CN4 plug on pins 3 and 4 blue and yellow wires with CN4 plu...

Page 22: ...ETWEEN PIN 4 ON CONTROL BOARD TERMINAL CN3 AND GROUND Condition Disconnect CN3 plug from control board On Off switch is on Check for 24 VAC between pin 4 of the CN3 terminal on the control board and g...

Page 23: ...is on Insert one meter probe into the back of CN3 plug pin 1 check for 24 VAC between here and ground with CN3 plugged in and power on See illustration above for pin number locations STEP 5 24 VAC FRO...

Page 24: ...r resistance value is off significantly ohm reading does approximately correspond to table at given temperatures continue to Step 7 WATER TEMP OHMS RESISTANCE C F 3 21 40 70 26 435 11 974 37 5 49 100...

Page 25: ...ed inlet switch does not show continuity replace switch blocked inlet switch does show continuity continue blower proving switch does show continuity replace switch blower proving switch does not show...

Page 26: ...IN 1 AND 2 Condition Reconnect all plugs to control board On Off switch is on Call for heat is activated Insert meter probes into back of CN2 plug on pins 1 and 2 with CN2 plugged in power on and a ca...

Page 27: ...tion a negative or positive room air pressure can cause erratic switch operation and the water heater to shut down If you suspect a pressure imbalance between the equipment room and the outdoor atmosp...

Page 28: ...wired together in a series circuit For the water heater to continue to fire and satisfy a call for heat the control board must sense a closed pressure switch circuit STEP 9B PRESSURE SWITCH CONTINUIT...

Page 29: ...VAC TO IGNITOR FROM PIN 1 AND 2 ON CONTROL BOARD TERMINAL CN5 Condition Disconnect CN5 plug from control board On Off switch is on Call for heat is activated Perform test during ignitor warm up perio...

Page 30: ...ECK RESISTANCE BETWEEN TWO WIRE CONNECTS AT CN5 IGNITOR PLUG END Condition On Off switch is off Disconnect CN5 ignitor plug from circuit board Multimeter is set to lowest ohms scale above 300 ohms STE...

Page 31: ...Touch meter probes to wiring terminals on gas valve with wires from control board still connected during the ignitor warm up period STEP 12 24 VAC TO GAS VALVE IF AND THEN 24 VAC is not present to gas...

Page 32: ...tween 5 0 and 14 W C natural gas or 11 0 and 14 W C propane adjust supply gas pressure Recommended supply minimum is 7 0 W C for natural gas models proper supply gas pressure is present continue to St...

Page 33: ...pered end FLAME SENSING ROD PART NUMBER FLAME SENSING CURRENT COMMENTS 192478 0 7 Micro Amp SUF 150 199 240 HOT SURFACE IGNITOR HSI PART NUMBER VOLTAGE AMP OHMS COLD COMMENTS 192638 120 VAC 1 0 50 300...

Page 34: ...S U F S E R V I C E H A N D B O O K C O M P O N E N T I N F O R M A T I O N State Water Heaters Technical Training Department Ashland City Tennessee 2004 33 STC 077 PRESSURE SWTCHES...

Page 35: ...eceded by a plus sign and indicate pressure above atmospheric Model Blocked Inlet Normally Closed Opens on a fall Blower Prover Normally Open Closes on a rise Low Gas Pressure Normally Open Closes on...

Page 36: ...S U F S E R V I C E H A N D B O O K W I R I N G D I A G R A M S State Water Heaters Technical Training Department Ashland City Tennessee 2004 35 STC 077 WIRING DIAGRAMS...

Page 37: ...ence of operation comments on when to push this button 6 If you make a setting change cycle the heater with this new setting to lock it into memory 7 The first items to check on a service call a Corre...

Page 38: ...er inlet and outlet are 4 PVC If venting with a 4 PVC a 4 x 4 PVC coupling field supplied must be cemented to each end of the muffler If venting with 3 PVC a 4 x 3 PVC reducing coupling field supplied...

Page 39: ...ons is hard and 10 5 grains per gallon is very hard An aspirin is about 5 grains One grain is equal to 17 1 parts per million A Deliming should be done when a slight rumbling or popping sound is detec...

Page 40: ...ower Prover Switch operation check normally closed Blocked Outlet Inlet and Low Gas pressure SUF 240 only to ensure they remain closed Check for blocked vent pipe s or if equivalent feet venting limit...

Page 41: ...V WATER PIPING Is the system properly sized yes no Is the system properly installed yes no Are there any water leaks yes no Does the installation have a recirculating system yes no If so is it operat...

Page 42: ...l Training Department Ashland City Tennessee 2004 41 STC 077 SUF SERVICE HANDBOOK PARTS LIST SUF MODELS 100 150 100 199 AND 100 240 STATE WATER HEATERS 500 LINDHAL PARKWAY ASHLAND CITY TN 37015 PHONE...

Page 43: ...6 72 191746 72 10 Direct Vent Kit 193202 193202 193281 193202 193202 11 Elbow 90 Degree 192473 192473 192473 192473 192473 12 Exhaust Terminal 192815 192815 192815 192815 192815 13 Flame Rod Assembly...

Page 44: ...362 193364 193357 193357 193357 3 Blower Proving Switch 193295 193295 193295 193295 193295 6 Cable to Control 192623 192623 192623 192623 192623 7 Control Board 193822 193822 193822 193822 193822 8 Di...

Page 45: ...S U F S E R V I C E H A N D B O O K P A R T S L I S T Technical Training Department State Water Heaters STC 077 44 Ashland City Tennessee 2004 N O T E S...

Page 46: ...The Expert s Choice COMMERCIAL...

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