Hydro Flame/Atwood problem

[Larry C]

My 2001 30' Excella has a furnace problem. It's been about 2 weeks since we've used the A/S,I usually use the heat pump, but I hadn't used the furnace for awhile, so decided to check it out. The first night, it worked fine, maintained temps at around 67 or so for the entire night..
The next night, I decided to use the furnace again, but when the thermostat called or heat, it would try to light, the burner would light, and stay lit for 5 to 6 seconds, then go off, for about 10 seconds, then go through the same sequence again. It would do this this three times, then stop trying to light. During this time the fan, and combustion chamber fan is running.
When we returned from the trip, I took it to our service center, they said they called Atwood, and that the igniter "might" be defective. Atwood told them that the ceramic insulator may be cracked, and moisture may cause the ignitor not to work. Since they already had the furnace out, I told them to replace the igniter. They did, and kept the trailer a couple days, during which it supposedly worked normally.
Which brings us to this morning. I had to use the AirStream, for a couple days, and since I paid $240.00 or so for the repair a couple weeks ago, decided to use the furnace, instead of the heat pump.
The furnace did the same thing as I described above. I'm pretty sure at this point that the ignitor is NOT the problem, and I don't think the problem is serious, but I need some help to figure it out.
Anyone who can help, it will be greatly appreciated!
Thanks,
Larry

[masseyfarm]

What model is the furnace?

The furnace was ignited and burning but failed. Always start by checking the sail switch and go from there. If you have low batteries, the blower speed will not run the sail switch fast enough to maintain contact?

I have some information on this thread.
http://www.airforums.com/forums/f313...tml#post975741

Dave

[Larry C]

Originally Posted by masseyfarm

What model is the furnace?

The furnace was ignited and burning but failed. Always start by checking the sail switch and go from there. If you have low batteries, the blower speed will not run the sail switch fast enough to maintain contact?

I have some information on this thread.
http://www.airforums.com/forums/f313...tml#post975741

Dave

Dave,
Thanks for the reply, the batteries are fully charged, and I'm currently connected to a 50 amp service at my home. However after reading a couple of the other links you provided, I wonder if the sail switch may be the problem.
I live in Lower Alabama, about 6 miles north of the Gulf of Mexico, there is usually a breeze coming off the Gulf, and there is a salt content in the air. Very possibly, either the contact are corroded, or the switch is defective.
i called Atwood yesterday, the service tech also said to check the gas pressure, it should be between 11 and 14" W.C., he said low gas pressure could give the same symptoms. My tanks are full, so that will be my next step, then the sail switch...
Thanks a lot for your help.
Larry

[Siegmann]

I don't know what model furnace you have, but on mine, the sail switch is an "air prover", a safety device that prevents the gas from flowing into the combustion chamber and igniting (boom!) if the fan is not running. The solenoid will not open without it working. You're getting gas and spark and ignition. I do not think the sail switch is your problem.

[Larry C]

Thje furnace model is 8500 IV, I'm finally buying a manometer, I've been putting that off for about 25 years, then I'll go through the check list that I got from Atwood. It could also be something as simple as a loose connection......
Thanks for your help.
Larry

[Siegmann]

With one brass fitting, a few feet of vinyl tubing and a scrap board (less than $5) you can build one yourself. Here is one example.

How to build a Manometer aka; Propane pressure test gauge

A google search will reveal many more.

Good luck.

[Larry C]

Originally Posted by Siegmann

With one brass fitting, a few feet of vinyl tubing and a scrap board (less than $5) you can build one yourself. Here is one example.

How to build a Manometer aka; Propane pressure test gauge

A google search will reveal many more.

Good luck.

Thanks for the input, I used to have a home built one, and it worked fine, and they are quite simple to build. I decided this time to buy one from Dwyer Instuments that is packaged with a case of it's own. It'll be a lot easier to put in my Airstream tool kit...
Larry

[Larry C]

OK, for whatever it's worth the furnace problem was found! The control panel (circuit board) was defective. So $220.00 later, the problem is solved.
This just goes to prove that just like the government, if you throw enough money at a problem, it usually (not always) goes away...

Larry

[masseyfarm]

Circuit board failure is not that common. Was it exposed to water?

Dave

[Larry C]

Originally Posted by masseyfarm

Circuit board failure is not that common. Was it exposed to water?

Dave

There were no signs of water exposure. It's a more common problem than most people realize. I had another one fail in our 2000 Excella. From what I understand, it's usually an intermittant problem, and takes awhile to find it....at any rate, it's fixed.
Larry

[jcanavera]

I guess the part of this story that somewhat upsets me was that who ever you took the trailer to did not fix your problem which led you to an unnecessary repair. If you took the trailer back, I hope you got some allowance for labor. To me, I'd rather give the dealer the symptoms and let them tell me what the fix is. I wouldn't agree to any repair unless I knew in advance that if they are guessing, that they will incur some costs if they "guess" wrong. At the least your previous labor should have been credited toward the final repair.

Jack

[jdalrymple]

Originally Posted by jcanavera

I guess the part of this story that somewhat upsets me was that who ever you took the trailer to did not fix your problem which led you to an unnecessary repair. If you took the trailer back, I hope you got some allowance for labor. To me, I'd rather give the dealer the symptoms and let them tell me what the fix is. I wouldn't agree to any repair unless I knew in advance that if they are guessing, that they will incur some costs if they "guess" wrong. At the least your previous labor should have been credited toward the final repair.

Jack

Seems to be more and more of a problem.

If device can't tell the "tech" what is wrong, they can't fix it.

I was on a trip with our '81 trailer when the furnace did the same thing. I used a VOM to convince myself the board was at fault.

I happened to stop by an old family owned RV shop and took my board in to match it to a new one. The gentleman would not sell me a new board without testing the old one in a test jig to confirm it was bad.

Too bad places like that are the odd lot now.



Regards,

JD

[Larry C]

Originally Posted by jcanavera

I guess the part of this story that somewhat upsets me was that who ever you took the trailer to did not fix your problem which led you to an unnecessary repair. If you took the trailer back, I hope you got some allowance for labor. To me, I'd rather give the dealer the symptoms and let them tell me what the fix is. I wouldn't agree to any repair unless I knew in advance that if they are guessing, that they will incur some costs if they "guess" wrong. At the least your previous labor should have been credited toward the final repair.

Jack

No need to be upset, Jack, after all, it was my problem, not yours. I've dealt with this service company for years, and trust them. It was an intermitent problem, due to the failing circuit board. There was no guessing involved, they have the proper diagnostic equipment, and they do know how to use it.
When the circuit board was working properly, the furnace worked properly, and checked out OK.
By the way, they did credit the full amount on the prior labor, and discounted the new circuit board. I couldn't ask for much more than that.

Larry

[Larry C]

Originally Posted by jdalrymple

Seems to be more and more of a problem.

If device can't tell the "tech" what is wrong, they can't fix it.

I was on a trip with our '81 trailer when the furnace did the same thing. I used a VOM to convince myself the board was at fault.

I happened to stop by an old family owned RV shop and took my board in to match it to a new one. The gentleman would not sell me a new board without testing the old one in a test jig to confirm it was bad.

Too bad places like that are the odd lot now.



Regards,

JD

JD, I think you have a pretty good fix on the problem, as what you describe is exactly what happened in this situation. I can do most of the service work on our AS, myself, but as I get older, I find myself using this company more often.

We travel a lot, and if we do have a problem, sometimes it's really difficult to find a reliable service tech. For whatever it's worth, this company is near our home, if you ever need service help in the Lower Alabama area, check them out.
"Country Man's RV Service" in Foley, Alabama.

Larry