Finned copper tube gas boilers & water heaters – Boiler Manual
35
SYMPTOM
CHECK
ACTION
9
Pilot Lights But Main Burners Will Not Fire
1. Bad flame sense lead from ignitor to
flame sense module
2. Defective flame sense module
3. Manual valve(s) in air plenum closed
4. Main valves(s) not wired
5. Low manifold pressure
6. Main valve(s) malfunctioning
1. Check sense lead & ground connections,
adjust as necessary
2. Replace flame sense module
3. Remove upper front jacket panel, open
manual valve(s)
4. Wire main valve(s)
5. Check manifold pressure during ignition
trial, adjust as necessary
6. Replace main valve(s)
10
Insufficient Heating
1. Operating control set too low
1. Increase control temperature setting
11
Unit Consistently Shuts Down
On High Limit
1. High limit set to low
1. Increase high limit setting
12
Bad Combustion
(High CO, Yellow Flames)
1. Insufficient air
2. Dirty inlet air filter
3. Too much air
1. Check CO & CO
2
, adjust blower inlet
damper(s) to increase airflow
Check for plenum air leakage from lower
front jacket panel seams, repair as
necessary
2. Remove, inspect and clean inlet air filter
as necessary
3. Check CO & CO
2
, adjust blower inlet
damper(s) to decrease airflow
13
Gas Flow Shuts Down During
Operation (Blowers Remain On)
1. Low air (blocked flue/inlet) condition
1. If condition exists, check inlet, flue,
chimney for blockage
Check combustion air/ventilation
openings in space
Check inlet air filter, clean/replace as
necessary
Check pressure switch for correct setting
TROUBLE-SHOOTING