MECHANICAL PROBLEM POSSIBLE CAUSE | CORRECTIVE ACTION |
When boiler is turned on nothing happens.
Thermostat in "ON" position causes relay and pump to operate, but boiler does not fire.
Pilot is not lit………………………………
No power to the boiler…………………...
Bad transformer………………………….
Inoperative thermostat…………………..
Inoperative toggle switch………………..
Inoperative relay………………………….
Main gas valve is closed……………….
Plugged bleed line on gas valve or
gas pressure regulator…………………..
Broken pump coupler……………………
Shutdown by low water
caused by air……………………………..
Gas valve defective………………………
Light pilot. (Standing pilot models) Check the circuit breaker, outdoor con- troller, etc., upstream of boiler.
If power to Leads L1 and L2 of trans- former, but no power on 24V side, re- place.
Jumper thermostat. Replace with new if boiler fires.
If power to toggle switch, but not through switch, replace.
If power to relay, but not operating, replace.
Open valve.
Loosen bleed line and clean.
Replace coupler. Inspect bearing as- sembly, and if frozen, lubricate or re- place.
Bleed air from system.
Check for power to gas valve. If valve has power but will not open, check vent tube for blockage. If clear, replace valve.
Continuous shut down of manual reset Temperature setting too low…………….
high limit. | Low water flow…………………………… |
| Interrupted pump operation…………….. |
| Modulating control set too high……….. |
| Mechanical modulating control………… |
Reset high limit to higher temperature. Check system water pumps.
Check pump oil if necessary. Reset modulator to a lower setting. Check and replace if necessary.
Sooting
Air starvation……………………………..
Condensation……………………………..
Toxic fumes which cause a chemical reaction with copper tubes or destroy combustion……………………………….
Improper venting…………………………
Refer to installation instructions regard- ing combustion air requirements.
Set bypass valve to prevent boiler inlet temperature from dropping below 105 °F.
Remove all sources of fumes, such as freon, chloride, or isolate the boiler. Follow recommended vent installation instructions.
Continuous shut down of low water cut- Insufficient system flow………………….
off or flow switch. | Low water due to leaking……………….. |
| Air in system……………………………… |
| Line strainer dirty………………………… |
| Lime in heat exchanger………………… |
Low flame. | Gas supply……………………………….. |
| Insects or debris clogging burners |
| Burner intake ports low gas pressure…. |
| Venting or combustion air………………. |
Outer jacket very hot (blistered paint). Broken refractory…..…………………….
Check pumps and piping. Inspect for leakage and repair. Inspect for leakage and repair. Install an automatic air vent.
Clean. Ream tubes.
Debris in gas line (pipe dope, rocks, etc.). Gas line too small.
Improperly sized gas meter. Gas regulator adjustment. Clean burners.
Adjust gas pressure.
Refer to installation instructions regard- ing combustion air requirement.
Replace refractory panels.
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