PB Heat MIH manual Problem Possible Causes Corrective Actions

TROUBLESHOOTING

Table 8.1: Boiler Troubleshooting Guide

PROBLEM

POSSIBLE CAUSES

CORRECTIVE ACTIONS

Burners not functioning.	1.	No power.	1.	Check line voltage wiring and fuses.
	2.	Limit (Aquastat) not working.	2.	Check wiring and contacts, relay, temperature
				setting. Clean and adjust as necessary.
	3.	Flame rollout switch open.	3.	Replace switch. Locate cause and correct.
	4.	Blocked vent switch open.	4.	Reset blocked vent switch. Locate cause and correct.
	5.	Gas off at boiler gas valve.	5.	Start boiler using Lighting/Operating
				Instructions.
	6.	Gas off external to boiler.	6.	Check any gas valves in the line.
	7.	Plugged orifice spuds.	7.	Check, clean and re-install.
	8.	Defective gas valve.	8.	Use Figure 8.1 to troubleshoot intermittent
				ignition gas valve. Replace if necessary.
	9.	Improper wiring.	9.	Check and correct in accordance with wiring
				diagrams in Section 6.
	10.	Vent damper malfunctioning.	10.	Refer to vent damper manufacturer’s instructions.
				Replace if necessary.
Burners will not shut	1.	Defective gas valve.	1.	Use Figure 8.1 to troubleshoot intermittent
down.				ignition gas valve. Replace if necessary.
	2.	Short circuit.	2.	Check and correct wiring.
Flashback or burning	1.	Manifold gas pressure too low.	1.	Adjust to proper pressure.
at orifice spuds.	2.	Improperly sized/drilled orifice spuds.	2.	Install correct spuds.
	3.	Leaking gas valve.	3.	Replace valve.
	4.	Burrs on orifice.	4.	Remove burrs.
	5.	Low supply gas pressure.	5.	Contact gas supplier if natural gas. Adjust
				regulator if LP gas.
	6.	Excessive downdraft or draft problems in	6.	Check air supply, ventilation and venting system.
		boiler room.
Delayed ignition.	1.	Insufficient pilot flame.	1.	Increase pilot gas flow.
	2.	Pilot burner/orifice clogged.	2.	Clean pilot burner and orifice.
	3.	Overfiring.	3.	Reduce rate to input on rating label.
	4.	Misaligned burners or pilot.	4.	Realign burners or pilot.
	5.	Draft problem in boiler room.	5.	Check air supply, ventilation and venting
				system.
Excessive condensation in	1.	Underfiring.	1.	Increase rate to input on rating label.
vent.	2.	Limit (Aquastat) set too low.	2.	Reset aquastat to higher setting.
	3.	Vent pipe too long.	3.	Reposition boiler to reduce length.
	4.	Inadequate chimney or venting system.	4.	Check chimney and venting recommendations.
Boiler not heating	1.	Underfiring.	1.	Increase rate to input on rating label.
properly.	2.	Limit set too low.	2.	Reset aquastat to higher setting.
	3.	Air in system.	3.	Vent air from all points in system.
	4.	Circulator malfunctioning.	4.	Check circulator, replace if necessary.
	5.	Circulation system clogged.	5.	Shut down and cool boiler, drain and flush
				system.
	6.	Incorrect thermostat heat anticipator setting.	6.	Adjust heat anticipator.
Fumes or gas odors	1.	Leaks in gas piping or fittings.	1.	Locate and repair or replace.
	2.	Leaks in gas service line or meter.	2.	Shut down boiler and notify gas provider.
	3.	Obstructed chimney.	3.	Check, repair and/or clean chimney.
	4.	Obstructed flueways or vent.	4.	Clean flueways or vent and remove obstructions.
	5.	Undersized chimney or vent, high draft loss	5.	Check National Fuel Gas Code and vent
		in vent.		manufacturer’s recommendations.
	6.	Draft problem in boiler room.	6.	Check air supply, ventilation and venting system.
	7.	Overfiring.	7.	Reduce rate to input on rating label.
	8.	Vent damper malfunctioning.	8.	Refer to vent damper manufacturer’s instructions.
				Replace if necessary.

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