Luxaire Furnace doesnt always fire - DIY Chatroom

sdise · 11-13-2008, 10:05 PM

I have a luxaire furnace model # G/UA036SA. Here is the process of my problem:
1. Furnace comes on.
2. Exhaust fan runs(I assume to evacuate any gas buildup)
3. Exhaust fan still runs 3 to 5 mins then ignitor glows, audible click sound(safety valve opens), gas enters but does not always light.
4. When gas starts to enter ignitor stops glowing, no ignition, and safety valve closes.

Is this valve issue or a fan timing issue? It seems like the ignitor should glow longer for the gas to ignite off of it.

kennzz05 · 11-13-2008, 10:20 PM

thats along time from fan start to valve opening but id try cleaning the flame sensor it looks like a silver piece of metal usually coming from the bottom of the burner area and sticks into one of the flames created by one of the burners also usually has one single wire on it (sometimes white) just lightly sand it or use steelwool and reinstall it making sure its completely engulfed by the flame when its lit if it isnt the burners need to be cleaned let me know what happens...ken

After rereading your problem id suggest you remove your burners and wash them out with a hose or kitchen sprayer in kit sink if they are dusty gas cant flow across the pilot rail as well and gas cant get to the ignitor When the furnace dosent see a flame on the first attempt it usually will run the inducer for a prolonged amount of time on subsequent attemts to purge the heat exchanger of raw gas. still follow above advise to clean sensor

beenthere · 11-14-2008, 07:32 AM

A. Thats the model number of your A/C coil. Furnace mod number will be inside the furnace.
B. Sounds like a problem with the inducer, or venting. Taking too long to establish good draft.

jabass · 11-16-2008, 01:31 AM

I had a similar problem with my American standard Freedom 90 furnance and the fix was to increase the W.C. from 8 to 10 for my propane run furnace.

sdise · 11-19-2008, 09:46 PM

Thanks for the info of where to look. Model number is PCMU-LD12n076B. Cleaned the igniter and it broke.
Replaced the igniter last night with a new one and the problem is still happening.

kennzz05 · 11-19-2008, 11:02 PM

Quote:

Originally Posted by sdise

Thanks for the info of where to look. Model number is PCMU-LD12n076B. Cleaned the igniter and it broke.
Replaced the igniter last night with a new one and the problem is still happening.

ignitors dont get cleaned(guess you figured that out

)
did you remove and wash the burners
is there a flame sensor, metal rod with a single wire on it opposite end from ignitor?if so thats what gets cleaned

info · 01-31-2009, 02:30 PM

Quote:

Originally Posted by sdise

Thanks for the info of where to look. Model number is PCMU-LD12n076B. Cleaned the igniter and it broke.
Replaced the igniter last night with a new one and the problem is still happening.

I had a similar problem last night, guy came and fixed it, said it was the exhauster, charged me $600, trying to figure out if he ripped me off

yuri · 01-31-2009, 03:00 PM

Wash out or blow out the burners with compressed air.

beenthere · 01-31-2009, 06:11 PM

Quote:

Originally Posted by info

I had a similar problem last night, guy came and fixed it, said it was the exhauster, charged me $600, trying to figure out if he ripped me off

If its working, and you have heat.

He didn't rip you off.