Troubleshooting, Observed Problem, Possible Cause, Remedy

TROUBLESHOOTING

Note: For additional help, visit DESA’s technical service web site at www.desatech.com.

Note: Before troubleshooting the system, make sure the gas shutoff valve is ON.

WARNING: Turn off heater		CAUTION: Never use a wire,
and let cool before servicing. Only		needle, or similar object to
a qualified service person should		clean pilot. This can damage
service and repair heater.		pilot unit.

The two most common causes of a malfunctioning gas appliance are:

1.Loose wiring connections

2.Construction debris clogging the pilot and/or gas control valve filter

OBSERVED PROBLEM	POSSIBLE CAUSE		REMEDY
Ignitor will not spark or pilot will not light	1.	No gas supply, or shutoff valve is OFF	1.	Check to see if you have gas supply and
				that equipment shutoff valve is opened
	2.	Air in gas line	2.	Repeat lighting procedure several times
				to purge all air out of lines. If after re-
				peated attempts appliance does not light,
				call for qualified service and repair.
	3.	Construction debris clogging pilot orifice	3.	Remove debris and dirt, inspect and
				clean any other possible obstructions
	4.	Low gas pressure	4.	Contact your gas supplier to check
				pressure
	5.	Kinked pilot line	5.	Have a qualified technician replace pi-
				lot line
	6.	Control valve knob is not opening	6.	Replace control valve (Refer to Replace-
				ment Parts, page 29)
	7.	No power to unit or the ignition module	7.	Check that main power is on and that all
		or power transformer is bad		wire connections are made correctly to
				the ignition model (see Wiring Diagram,
				page 23). Check for 24 VAC at the sec-
				ondary side of the transformer. If 24
				VAC is present, and the module does not
				oporate, have the module replaced oth-
				erwise have the transformer replaced.
	8.	Vent damper not fully open	8.	Open vent damper until fully locked in
				OPEN position

Pilot will not stay lit	1.	Loose wiring on ignitor wire to ignition
		module and/or poor ground to ignition
		module
	2.	Pilot flame too low to sense

1.Check wiring connection. Refer to wir- ing diagram (see Wiring Diagram, page

23)and/or check ground wire to igni- tion module

2.Clean and adjust pilot burner and check gas supply and inlet pressure to unit

Note: Have a qualified technician replace pilot assembly if broken or corroded

No gas to burner, although wall switch and	1.	Wall switch wires defective or too long	1.	Check electrical connections
valve are set to the ON position

Frequent pilot outage	1.	Pilot flame may be too low, causing	1.	Clean and adjust pilot flame for maximum
		safety pilot to “drop out”		flame impingement on thermopile
	2.	Improper venting or excessive blockage	2.	Have the vent system inspected, includ-
				ing the termination cap. Remove any
				restriction or obstruction