5.As soon as the pilot gas valve is energized, check for the burner pilot flame through the burner
•Turn the burner switch to “OFF” position for at least one minute to reset the heater.
•Check for 24V between “PV” terminal and “MV/PV” terminal after 45 seconds prepurge cycle (this 24V may only last 15 seconds starting after 45S prepurge). If there’s no 24V at the “PV” terminal ever, and there’s 24V at “24V” terminal, the Honeywell flame control module needs to be replaced.
•If 24V is detected for a period of 15 seconds, check for the changes of gas supply line pressure when the pilot gas valve is energized. If no visible pressure change during the pilot ignition period, check for loose connection of the pilot valve or a defective pilot gas valve.
•Adjust the pilot gas regulator setting during the pilot ignition period (15 seconds). Do not set too much or too little pilot gas. This adjustment should only be performed during the 15 seconds ignition period. A clockwise or
•If still no pilot flame inside the burner, check for the spark ignitor wiring, ignitor tip location and visually check the spark (burner pilot assembly needs to be taken out for the visual check). Refer to the burner manual for detailed spark ignition troubleshooting procedures.
6.Pilot flame established but not detected by the flame control module. Use Micro Amp meter to measure flame signal during the pilot ignition period. Refer to burner manual for testing procedures.
•If pilot flame is confirmed visually through the burner peek hole, and the flame signal is zero, the
•If it’s confirmed that the thermal cutoff switch is damaged
(open), call the State Technical Center to analyze the root cause (too lean combustion) and proper gas/air ratio adjustment. Flashback will cause the thermal cutoff switch broken (open).
•If the flame signal is not zero but below 1µA, relocate flame rod or replace flame rod will be required. Refer to burner manual for detailed procedure of replacing flame rod.
MOTOR RUNS CONTINUOUSLY, BURNER LIGHTS ON MOMENTARILY THEN LOCKS OUT OR EXCESSIVE ON/OFF CYCLE
Under this condition, the burner will start the purge cycle again, then pilot ignition and main flame cycle. If main flame cannot be sustained:
1.Make sure main manual gas valve (right after the Robertshaw gas valve) is fully open;
2.Check for 24V at the Robertshaw gas valve when the main gas light is on. If there’s no 24V at the valve, check loose wire connection.
3.Check for gas supply line pressure. The gas line pressure before the valve should be maintained at minimum 8” w.c. when main flame is “ON”. If the gas line pressure drops below 8” w.c. (2 kPa), the service regulator pressure setting must be increased to keep 8” w.c. (2 kPa) minimum gas pressure. After adjusting the gas regulator setting, turn off the heater, make sure the gas line pressure does not exceed 14” w.c. (3.5 kPa) if it does exceed 14” w.c. (3.5 kPa) static pressure, the gas supply line size must be increased accordingly to avoid gas line pressure exceeding 14” w.c. (3.5 kPa)
4.Check the gas valve manifold pressure (refer to Table 10), see ADJUSTMENT PROCEDURE to adjust the manifold pressure.
5.Check for defective gas valve for failing to open or shut off.
6.Verify that the air supply is adequate. The air inlet screen or blower wheel may be restricted.
7.Check the installation for proper ventilation, see AIR REQUIREMENTS.
8.Verify the air switch setting is not too high.
9.Check the venting system for the correct sizing, excessive or insufficient draft, and proper operation of the barometric draft control, see VENTING.
NOISY BURNER OPERATION
1.Check for flue gas excess O2 or CO2 reading (refer to Table 10). If combustion is too lean (flue gas O2 reads more than 7.5%), the combustion flame front may not be stable, which will cause noisy operation. See ADJUSTMENT.
2.Check the venting system for the correct sizing, excess or insufficient draft, and proper operation of the barometric draft control, see VENTING.
3.If the burner operation is still noisy, then remove the burner, examine the burner diffuser,
GAS FAILS TO SHUT OFF
Check for defective gas valve or thermostat. If operation is incorrect, replace.
REPLACEMENT PARTS
Replacement parts may be ordered through State dealers, unauthorized servicers or distributors. Refer to the Yellow Pages for where to call or contact the State Water Heaters, 500 Lindahl Parkway, Ashland City, TN 37015,
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