Visit our Popular Forums

tcarr · 12-08-2020, 04:45 PM

Renovating a 94 Excella that sat up for 10 years. I connected the LP for the first time and set the thermostat to about 75 and turned it on and the fan started blowing after a few moments followed by a click and the sound of the furnace igniting and I had hot air coming out of the ducts. It was a little dusty as it had not been run in a while so I turned it off and vacuumed out the air ducts. The second time I turned it on I never heard the woosh of the pilot igniting and the unit only blew cold air. I had a look, noticed a fuse (5 A) was burned out. Quick trip to the store, replaced the fuse and repeated the steps above, and the fuse burned out again before the pilot lit. I’m thinking it’s something with the circuit board. Has anybody dealt with this issue?

**GCinSC2** · 12-08-2020, 05:27 PM

Higher than design current draw blowing the fuse?

Blower motor starting to seize?
Bad connections to motor resistance is again drawing high current.
Bad ground wiring.
Debris blocking fan again high current.

Speculations comments not proven by inspection or any testing.

CBWELL · 12-08-2020, 06:14 PM

My furnace was doing the same thing. Replaced motor and both the combustion air fan and the heated air fan. Problem solved! Bought all the parts from Amazon. Replaced the sail switch at the same time.

BayouBiker · 12-08-2020, 06:50 PM

From the symptoms I would fault the combustion air fan or the sail switch. Before replacing them, I would clean the connections. Since it was working and then you cleaned the ducts, that points to a poor connection on the sail switch. A poor connection reduces voltage causing the current required to drive the fuel solenoid and combustion fan to rise. So clean the sail switch well including the connectors. Clean the other connections while you are at it. If you don't have electro wash, use alcohol.

**GCinSC2** · 12-15-2020, 05:57 AM

Tcarr,

Update any luck?

Gary

tcarr · 01-17-2021, 08:44 AM

That’s for all the previous advice. Sail switch was fine and the unit was remarkably clean of dust. After troubleshooting, it was determined that one of the coils was bad. Should be an easy fix...except I can’t get to the coil as it sits right up against the top of the furnace housing. And there is no easy access to this from the back. Further, I can’t figure how to get the unit out because there is a 4th smaller duct coming out of the back bottom of the furnace box preventing t from moving forward and the screw securing it in place faces away and unreachable by screwdriver. I’m pretty fed up at this point.

I’ve watched a few videos where guys remove screws on the outside, disconnect the ducts, and it slides right out. Not mine I can only assume that the furnace was installed early in the process at the factory and cabinets were installed on top of it with no thought to future maintenance.

Sorry for the rant. Has anyone ever replaced a coil and if so, how?

Please pardon any typos. I’m dictating. Thank you in advance

BayouBiker · 01-17-2021, 12:23 PM

I'm not sure what coils you're talking about. Needless to say, I've never replaced one. If you have a saws all and access or a mini all purpose reciprocating tool you may be able to cut the screw...

tcarr · 01-21-2021, 06:03 PM

UPDATE: PROBLEM SOLVED.

I removed the external furnace door and from the inside, disconnected the ducts, labeled the wires to the thermostat and power, cut and capped them, and removed the furnace from the inside. I used my grinder with a cutting wheel to access the coils. Disconnected the wires and removed the coils. The one causing the 5A fuse to trip was obviously blown/melted. Slid the new ones on (purchased from Amazon for $36, reconnected the wires, closed the lid and fastened with a few rivets. I then reinstalled the furnace, connected the propane line, turned on the thermostat, heard the fan kick on, the green light on the circuit board switched to red (without the fuse blowing) the valve opened and the pilot lit and - heat began to flow. Im Hopefully this helps someone. PM me for questions. link to a few images: https://imgur.com/zzF7YpO

BayouBiker · 01-21-2021, 06:20 PM

Oh the ignitor coils, of course! I was stumped.... Glad you were able to get the furnace out.

**GCinSC2** · 01-22-2021, 05:24 AM

The black coils in your hand, that's what you replaced?

Pretty sure those are the dual gas valve solenoid coils.

And that entire burner assy can be removed w/o removing the entire furnace. You remove some small screws, disconnect couple wires, gas line, exhaust pipe and wiggle it out.

Similar repair here.

EDIT: I have not tried this repair on your model, mine, yes. Several times to clear bugs out.