EPV SERIES CONDENSING WATER BOILER
34-501 07/13
20
TROUBLESHOOTING SUGGESTIONS
GAS BURNER
1.
BURNER FAILS TO START:
a) Defective on/off switch. Replace switch.
b) Control circuit has open control contact. Check limits, low water cutoff, and others as applicable.
c) Bad fuse or switch opens on incoming power source. Correct as required.
d) Flame safeguard control safety switch tripped out. Reset and determine cause of apparent flame failure.
e) Loose connections or faulty wiring. Tighten all terminal screws and consult wiring diagram furnished with the
heater.
f) Flame safeguard control starting circuit blocked due to flame relay being energized. Possible defective
scanner or flame rod – replace. Possible defective amplifier – replace. Scanner actually sighting flame due to
leaking fuel valve – correct unwanted flame cause. Defective flame safeguard control – replace.
g) Defective blower motor. Check for free rotation of fan wheel. Repair or replace.
h) Air proving switch is not properly adjusted. Adjust per instructions; page 13, paragraph 17.
i) Defective circulation pump. Repair or replace.
j) Regulator vent line(s) plugged. Remove blockage.
2. OCCASIONAL LOCKOUTS FOR NO APPARENT REASON:
a) Gas pilot ignition failure. Check to see that ignition is instant and flame signal readings are stable and above
minimum values. Use an incline manometer to make certain pressure is as recommended.
b) Loose or broken wires. Check all wire nut connections and tighten all terminal screw connections in panel and
elsewhere as appropriate.
c) With flame safeguard controls that incorporate the air flow switch in the non-recycling circuit, ensure that
when main flame lights, the air flow switch is not so critically set as to allow occasional momentary opening of
the air switch contacts.
d) Occasional low supply voltage. Contact local utility to correct. Make certain the burner control circuit
transformer (if supplied) is correct of the voltage and power (AC) being supplied.
e) Occasional
low gas supply pressure. Contact local utility to correct.
f) Regulator vent line(s) plugged. Remove blockage.
g) Excessive flue gas recirculation, causing unreliable or unstable operation. Reduce the orifice size in the FGR
union and readjust the gas regulators to achieve proper excess air in combustion.