Gas heat

[Gonefishing]

Has anyone ever heard of this. Been having problem with heat on gas. Turn on it runs 3-5 seconds and cuts off. Was told sail switch issue. Removed sail switch if held in hand it runs fine. Install does the same thing. Had technician out said bad sail switch replace same thing. Technician back out said motor problem not pushing enough air to close sail switch. Ordered motor different technician comes runs a check says it’s not the motor. Problem he says is someone changed the squirrel cage on the motor and replaced with wrong one. Says it’s too short therefore air is not hitting the sail to engage the switch. You can put your finger in the hole where the sail switch goes and fill the top of the cage. When sail is installed it is above the gage. So it makes sense to me. Anyone ever heard of this?

[R.S.O'Donnell]

Ours did the same. I loosened and reinstalled the igniter/flame sensor and that fixed it. My conclusion was it wasn’t “seeing” the flame and was cutting the gas off. I can only surmise it was a ground issue.

[Kyle and Lisa]

Always check for exhaust air flow first, remove piping and inspect with a flashlight for dirt dobber nest.

[LeftOverParts]

So from this post and your post on the sail switch, looks like the heater will work as it should. Seems if the tech thought the cage was wrong, they would have offered to get you the right one or given you the info to order one. If not, if you can get the model number of the heater, you should be able to order a new cage. Amazon is one option as they have some Dometic heater squirrel cage fans. Getting a diagram or picture of the right one should help you confirm what is supposed to be there.

Here's a link to edometic for Domitec heaters. It has parts lists and exploded views. The cage is called a, combustion wheel.

https://edometic.com/allusr/sp.nsf/spcaf?ReadForm

800-544-4881 E-Mail: customersupportcenter@dometic.com

Maybe one more thing to try: The cage is clamped to the motor shaft. It may have slipped. Or, the shaft might be long enough to relocate the cage so it's closer to the sail so you can test the theory that it's too far from the sail.

Amazon link to a Dometic cage. Not saying it's the right one but you can see the spring clamp for the shaft.

https://www.amazon.com/Atwood-33128-.../dp/B00JXO2TU8

[ChuckS]

If it were mine I would take my multimeter, set to Ohms scale (x1 range)..

With sail switch installed remove both leads and place meter leads across the connections on the sail switch.. should read OPEN .. no continuity

Now have helper turn on the furnace with meter still connected and observe the meter reading when blower motor spins up .. should read close to 0.0 ohms

If so then you now know the blower is moving the paddle arm enough to complete the circuit and can focus your troubleshooting elsewhere...

[ChuckS]

You should also verify you have the latest PN Sail switch that Atwood recommends for the AFM/DFM 35 series units

https://pantherrvproducts.com/33082/

Sometimes you have to shape the paddle arm a tad if there is any interference when the paddle arm is installed

[Todd & Mary]

Ensure all of your registers are open, not covered with rugs, box's or anything else. That can cause enough restriction to cause the issue by restricting airflow from the furnace also.

[Bourbon County]

You say it runs for 3-5 seconds; does the burner actually light and burn for that length of time, or just the draft induction blower? If the burner actually lights, it's likely not a sail switch or blower issue. The flame sensor would be the next logical thing to check.

[Gonefishing]

Just an update new cage came in will be installing soon. We let you all know if that fixes the problem. We will see. I sure hope so. Been using the elect heat pump but since temps have been cold at night the heat pump doesn’t work all that good.

[GreG L.]

I had the same issue, turned out to be the Black 15 amp self resetting fuse tripping too soon and then resetting, replaced it with a blue 15 amp and all worked fine. Quick and easy check, open the fuse panel turn on the heater, if it is the fuse the LED will come on when the heater goes off then go out when it resets.

[mtheo]

Had the same problem last year, turn out to be resettable fuse. Took me three day to figure that one out. Just remove black fuse and replace with 15 blue.

[Gonefishing]

Okay now have heat. Problem was the cage tech said what happen the cage had hit the sail switch and damaged the cage.

[LeftOverParts]

Glad to hear it and thanks for closing the loop! Seems like a strange thing to happen but your other post that there wasn’t enough air pressure to close the sail was correct!

[Gonefishing]

Originally Posted by LeftOverParts

Glad to hear it and thanks for closing the loop! Seems like a strange thing to happen but your other post that there wasn’t enough air pressure to close the sail was correct!

Correct all is good not. Kicking out the heat.