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Finned copper tube gas boilers & water heaters – Boiler Manual
37
F
F
PROBLEM
POSSIBLE CAUSES
CORRECTIVE ACTION
Unit Sparks But Will Not Fire
Low gas pressure
Check gas supply pressure, adjust as necessary
Pilot valve manual knob closed
Open pilot valve manual knob
Pilot wires disconnected
Reconnect wires
Low pilot pressure
Check pilot pressure, adjust as necessary
Pilot valve malfunctioning
Replace pilot valve
Pilot Lights But Unit Will Not Fire
Bad fl ame sense lead from ignitor to fl ame
Check ground connections, adjust as necessary
sense
module
Manual valve(s) closed
Remove upper front jacket panel, open manual
valve(s)
Low manifold pressure
Check manifold pressure, adjust as necessary
Main valve(s) malfunctioning
Replace main valve(s)
Insuffi cient Heating
Target temperature too low
Increase stage control target temperature
Primary (safety high) limit set too low
Increase limit sett ing
Unit Consistently Shuts Down
Primary (safety high) limit set to low
Increase limit sett ing
On Limit
Bad Combustion
Insuffi cient air
• Check CO, adjust blower inlet damper(s) to
(High CO, Yellow Flames)
increase airfl ow
• Check for plenum air leakage from lower front
jacket panel seams, repair as necessary
Dirty inlet air fi lter
Remove, inspect and clean inlet air fi lter as
necessary
Too much air
Check CO, adjust blower inlet damper(s) to
decrease
airfl
ow
Gas Flow Shuts Down During
Low air (blocked fl ue/inlet) condition
• Check indicator board for low air indication
Operation (Blowers Remain On)
air indication
• If condition exists, check inlet, fl ue, chimney for
blockage
• Check combustion air/ventilation openings in
space
• Check inlet air fi lter, clean/replace as necessary
TROUBLE-SHOOTING
