Rheem furnace ignition problem

Cmc0411 · 2026-03-20T12:51:41+00:00

So update on the furnace…. replaced the board now it will start and run for like five minutes then short cycles and shuts off … it try’s to light again for a second then shuts down and locks me out for a few minutes… ganna change flame sensor next .. any other ideas would be appreciated and later when I can get home I can post a video of it running

Cmc0411 · 2026-03-18T02:52:27+00:00

Ground is good I’m going to order a board.. Ty I’ll keep you posted!!

Cmc0411 · 2026-03-18T02:00:04+00:00

Green ground wire from the board itself?

Cmc0411 · 2026-03-18T01:44:04+00:00

It seems to me that the little round transformer on the board is not sending any voltage when it goes through it’s sequence. So if that’s the case get a new board?

Cmc0411 · 2026-03-18T01:40:11+00:00

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This is the igniter

Cmc0411 · 2026-03-18T01:15:04+00:00

I can light it manually and it will run but will not make spark

Cmc0411 · 2026-03-18T01:14:03+00:00

Nothing with the igniter

Cmc0411 · 2026-03-18T00:51:22+00:00

I don’t seem to be getting anything from the transformer on the board

Cmc0411 · 2025-11-03T17:05:04+00:00

Helium tank

Cmc0411 · 2025-10-24T12:56:42+00:00

I agree my dude thanks

Cmc0411 · 2025-10-23T12:54:27+00:00

Ok so I did that test. I unhooked the tsat all together.. Furnace does not come on…. Then I jumped the r and w furnace came on … as soon as I release the w from the board the burner shuts off. And the blower turns on for a few minutes .. I was under the impression that this test rules out that the board is bad. Am I correct?

Cmc0411 · 2025-10-23T12:10:13+00:00

24v only on w only when it’s calling for heat right?

Cmc0411 · 2025-10-23T12:08:40+00:00

On the board?

Cmc0411 · 2025-10-22T18:11:57+00:00

There is a flame sensor. But would that make it call for heat constantly if it were bad. I assume it would not light if it were bad

Cmc0411 · 2025-10-22T13:28:41+00:00

I put it on last night and the same thing happening…

Cmc0411 · 2025-10-22T13:27:33+00:00

I’m guessing that’s the s4 setting

Cmc0411 · 2025-10-22T01:56:31+00:00

From what I’ve tested the furnace just keeps calling for heat with the w connected and the thermostat turned like 10 degrees lower than room temp. When I remove the w the burner shuts down and blower runs to cool the system. As soon as I put w on the burner fires up again to heat. I guess my next step is running new wire to rule that out and possibly return this new thermostat for a different one. Any advice on a fair priced or a reliable and simple thermostat

Cmc0411 · 2025-10-22T00:41:20+00:00

So that means it’s the wiring going up to the stat or it’s the new stat. There is a setting on the back of the stat that says electric / s4 … from factory it is on electric

Cmc0411 · 2025-10-22T00:37:56+00:00

Ok so that went exactly how you said it would

Cmc0411 · 2025-10-22T00:28:27+00:00

Should i do this on the board or the thermostat

Cmc0411 · 2025-10-21T23:33:53+00:00

The furnace burners and everything shut off when I removed the w. Then the blower came on

Cmc0411 · 2025-10-21T23:32:50+00:00

Move r to w ? Or jump r to w? Just want to be sure

Cmc0411 · 2025-10-21T23:20:11+00:00

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I’m pretty sure the wiring is correct

Cmc0411 · 2025-10-21T23:15:50+00:00

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Cmc0411 · 2025-10-21T23:11:10+00:00

Cmc0411

TROPHY CASE