Finned copper tube gas boilers & water heaters – Boiler Manual
37
TROUBLE-SHOOTING
SYMPTOM
CHECK
ACTION
7
Unit Does Not Spark
1. Incorrect spark gap or shorted ignitor lead
2. Bad ground on flame sense module
3. Low air (blocked flue/inlet) condition
4. Spark generator fault
1. Adjust ignitor rod or correct short
2. Check ground connections, adjust as
necessary
3. Check indicator board for low air indication
If condition exists, check inlet, flue,
chimney for blockage
Check combustion air/ventilation
opening in space
Check inlet air filter, clean/replace as
necessary
4. Check spark generator wiring
8
Unit Sparks But Will Not Fire
1. Low gas pressure
2. Pilot valve manual knob closed
3. Pilot wires disconnected
4. Low pilot pressure
5. Pilot valve malfunctioning
1. Check gas supply pressure, adjust as
necessary
2. Open pilot valve manual knob
3. Reconnect wires
4. Check pilot pressure, adjust as necessary
5. Replace pilot valve
9
Pilot Lights But Unit Will Not Fire
1. Bad flame sense lead from ignitor to
flame sense module
2. Manual valve(s) closed
3. Low manifold pressure
4. Main valve(s) malfunctioning
1. Check ground connections, adjust as
necessary
2. Remove upper front jacket panel, open
manual valve(s)
3. Check manifold pressure, adjust as
necessary
4. Replace main valve(s)
10
Insufficient Heating
1. Target temperature too low
2. Primary (safety high) limit set too low
1. Increase stage control target temperature
2. Increase limit setting
11
Unit Consistently Shuts Down
1. Primary (safety high) limit set to low
1. Increase limit setting On Limit
12
Bad Combustion
(High CO, Yellow Flames)
1. Insufficient air
2. Dirty inlet air filter
3. Too much air
1. Check CO, 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, 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. Check indicator board for low air
indication air indication
If condition exists, check inlet, flue,
chimney for blockage
Check combustion air/ventilation
openings in space
Check inlet air filter, clean/replace as
necessary
