EPV SERIES CONDENSING WATER BOILER
34-501 07/13
21
3. BURNER MOTOR RUNS, BUT PILOT DOES NOT LIGHT:
a) Gas supply to burner shut off. Make sure all manual gas supply valves are open. Automatic high-pressure
valve at meter such as "Sentry" type tripped shut due to high gas pressure. Reset valve and correct cause for
trip out.
b) Pilot solenoid valve not opening. Listen and feel for valve actuation. Solenoid valve not being powered. Check
electrical circuitry. Replace coil of entire valve if coil is burned out.
c) Defective gas pilot regulator. Replace.
d) Gas pressure too high or too low at pilot orifice (if supplied). Check orifice size in gas pilot assembly.
Replace if incorrect. Readjust pressure as required.
e) Defective ignition transformer. Replace. Incorrect ignition electrode settings. Readjust as required.
f) Defective component within the flame safeguard control. Replace as required.
g) Airflow switch not making circuit. Check out electrically. Defective airflow switch. Replace. ir switch negative
pressure sensing tube out of position. Reposition as necessary.
h) Regulator vent line(s) plugged. Remove blockage.
4. BURNER MOTOR RUNS AND PILOT LIGHTS, BUT THE MAIN GAS FLAME IS NOT ESTABLISHED:
a) Main shutoff or test cock closed. Check to make certain fully open.
b) Pilot flame signal reading too low to pull in flame safeguard relay. Readjust as required.
c) Defective automatic main or auxiliary gas shutoff valves. Check electrical circuitry to valves. Replace valves
or correct circuitry as required.
d) Main diaphragm shutoff valve opening too slowly. Adjust bleed on valve.
e) Defective flame safeguard control or plug on amplifier. Check and replace as required.
f) Main gas pressure regulator atmospheric vent line obstructed. Correct.
g) Defective main gas pressure regulator. Replace. Misadjusted main gas pressure regulator. Readjust to meet
required operational values.
h) Polarity reversed on incoming power (S89 control only). Correct.
i) Regulator vent line(s) plugged. Remove blockage.
5. CARBON MONOXIDE READINGS ON GAS FIRING:
a) Flame impingement on "cold" heat transfer surfaces caused by excessive firing rate. Reduce firing rate to
correct input volume.
b) Incorrect gas/air ratios. Readjust burner to correct CO
2
/ O
2
levels, eliminates all CO formation.
c) Excessive flue gas recirculation, causing insufficient excess air for complete combustion. Reduce the FGR
orifice size and readjust the gas regulators to achieve proper excess air in combustion.