furnace intermittent and will not stay on

jetlag · 12-10-2021, 03:38 PM

New 2021 Pinnacle, with a Dometic DFLD 40111 furnace. Planning a short trip end of December so I was testing the heat last night for the first time. It quit about the same time the stove quit, out of gas. We have been on the same 40G tank since taking delivery. Switched to a new tank this morning. It would run on fan only and then stop after a while. Opened the outside access to find 3 blinking red lights followed by a second pause, and back to the lights. manual says air in the lines and to run the stove to get some gas in the lines. I did. After that it starts, and after a few seconds, the igniter kicks in and lots of hot air out of the exhaust. This lasts for about 10 seconds and then it kicks back to fan only for a few more seconds. Then igniter kicks in again and this pattern is repeated 3 times after which it goes to fan and after a little bit, it cuts off. Called Dometic and she send me a file talking about an OEM issue where the gas line is over torqued? Not sure that is the problem, have a call to dealer and waiting to hear back from him. Anyone familiar with this? thanks

Parrott · 12-10-2021, 03:40 PM

Moisture on the control board will cause that symptom. Did you see any moisture in the access? Been raining?

jetlag · 12-10-2021, 03:43 PM

Quote:

Originally Posted by Parrott

Moisture on the control board will cause that symptom. Does your furnace have an outside access panel?

Yes, have been here all afternoon, it appears to be dry, didn't find any water inside. Removed and looked at the sail switch, seemed to be fine and clean as it has never been used.

jetlag · 12-10-2021, 03:50 PM

pictures of the furnace.

Parrott · 12-10-2021, 03:53 PM

Are your batteries fully charged. If low voltage the fan may not keep the sail switch engaged. For the future, they make a relocation kit to get the board up from the bottom to keep any moisture off of it. I keep a spare board for mine. Sounds like it is going through all the right things to light. Turn it on, when the fan starts you should hear the gas valve click and see if you smell gas coming from the exhaust pipe. If you smell gas and it doesn’t light, then it’s either the igniter or board. If you don’t smell gas then it could be the gas valve. If you do this with the access panel off, make sure to put the exhaust pipe in. I read you are getting hot air for a few seconds. Sounds like the board to me. Check with your dealer and see if he will let you try a board.

Parrott · 12-10-2021, 04:07 PM

Stove and water heater working ok?

jetlag · 12-11-2021, 06:17 AM

Quote:

Originally Posted by Parrott

Are your batteries fully charged. If low voltage the fan may not keep the sail switch engaged. For the future, they make a relocation kit to get the board up from the bottom to keep any moisture off of it. I keep a spare board for mine. Sounds like it is going through all the right things to light. Turn it on, when the fan starts you should hear the gas valve click and see if you smell gas coming from the exhaust pipe. If you smell gas and it doesn’t light, then it’s either the igniter or board. If you don’t smell gas then it could be the gas valve. If you do this with the access panel off, make sure to put the exhaust pipe in. I read you are getting hot air for a few seconds. Sounds like the board to me. Check with your dealer and see if he will let you try a board.

Thank You, yes batteries at 31V per Jaycommand app, and we are on 50A full time.

jetlag · 12-11-2021, 06:19 AM

Quote:

Originally Posted by Parrott

Stove and water heater working ok?

Stove is, unit is winterized for now so no water to the unit, but have had no issues with the tankless water heater. I switched to a new 40G propane tank.

Parrott · 12-11-2021, 07:21 AM

Here is a great video. Notice how his board is mounted up at an angle to keep it away from moisture that can get on the bottom.

https://www.youtube.com/watch?v=0t8v...IaCCSQ&index=2

jetlag · 12-11-2021, 07:23 AM

Quote:

Originally Posted by Parrott

Here is a great video.

https://www.youtube.com/watch?v=0t8v...IaCCSQ&index=2

Thanks, will watch, so far, the ones I have found have not been very good

jetlag · 12-11-2021, 07:34 AM

Double post, sorry. My problem is that it is lighting off, just not staying on for long, and cycling on/off 3 times before shutting down.

Parrott · 12-11-2021, 07:47 AM

Quote:

Originally Posted by jetlag

Double post, sorry. My problem is that it is lighting off, just not staying on for long, and cycling on/off 3 times before shutting down.

That is classic bad control board. Your unit is new and it doesn’t take much moisture to make them go bad. Take the board loose and look under it to make sure water isn’t under it. If you call Atwood/Dometic I’m pretty sure they will send you a relocation kit for your board and maybe a new board or they refer you to your dealer. If you have a good relationship with your dealer, they may let you use a board to check it versus hauling down to them. It’s a very common problem and the access panels leak all the time. I sealed around my access panel with silicone and Saran Wrap to keep rain out. Do you have a friend with a camper you could borrow their board. Like I said, I keep a spare board just for this.
I believe the 3 blinking lights means the unit is in lockout because the burner will not stay lit.
Not sure on your propane but could also be your issue.

Parrott · 12-11-2021, 08:15 AM

Quote:

Originally Posted by jetlag

Thank You, yes batteries at 31V per Jaycommand app, and we are on 50A full time.

Jay command says 31 volts? These unit work on 12 volts. Should be around 13.7 charging.

jetlag · 12-11-2021, 08:43 AM

Quote:

Originally Posted by Parrott

Jay command says 31 volts? These unit work on 12 volts. Should be around 13.7 charging.

Lol, what do they call it when you transpose numbers?? You are correct of course, and it is 13.1. had to laugh looking at what I had typed, would have surely cooked the batteries.

jetlag · 12-11-2021, 08:58 AM

Quote:

Originally Posted by Parrott

That is classic bad control board. Your unit is new and it doesn’t take much moisture to make them go bad. Take the board loose and look under it to make sure water isn’t under it. If you call Atwood/Dometic I’m pretty sure they will send you a relocation kit for your board and maybe a new board or they refer you to your dealer. If you have a good relationship with your dealer, they may let you use a board to check it versus hauling down to them. It’s a very common problem and the access panels leak all the time. I sealed around my access panel with silicone and Saran Wrap to keep rain out. Do you have a friend with a camper you could borrow their board. Like I said, I keep a spare board just for this.
I believe the 3 blinking lights means the unit is in lockout because the burner will not stay lit.
Not sure on your propane but could also be your issue.

Yes, thinking it might be the board. No friends near, but a buddy in Tampa with an identical Pinnacle, found water under his board. He called Dometic and they sent him a new board. His is also a /21 Unit like mine. Dealer unfortunately is over 300 miles away but has been very helpful in other areas so far. We talked and texted late yesterday, had me check the sail switch. It was clean, but if anything else is wrong with it I wouldn't know it. He may call me back today, if not, I will try Dometic again Monday. Board seems to be dry, but not sure how little moisture it takes to mess it up. The unit turns on as it is supposed to, fan runs for around 20 secs, then the ignition kicks in and very hot exhaust air immediately, so it is doing what it is supposed to, just cycling on/off 3 times before shutting down.

jetlag · 12-12-2021, 04:44 PM

Well!! left the damn thing alone Saturday, lots of other stuff to do around the farm. Today, Sunday and after church, mama wanted help making the bed in the RV getting ready for our short trip for new year's. it actually came with a Serta mattress that I thought was comfortable, but she complained, so she bought a mattress topper. Now, it is a production making the bed, and it takes two of us to get it done, lol. While out there, and I had planned to fiddle with the furnace some more again before calling Dometic again Monday, I turned it on, and it worked like a charm!!!! I let it run until she complained about the heat. Going back through the manual, and I am sure I read this and glossed right over, it said to wait one hour to try and run again? never did. Also, most of the attempts to relight the cover and exhaust piece were off. Dealer said it had to be on. Also, was there air still in the lines from switching tanks, although the stove was working fine? I will run it again in the following days. Stand by!! Thank You for your help. BTW, my buddy with the same Pinnacle in Florida, had to replace his, but he had water intrusion somehow.

Parrott · 12-12-2021, 07:01 PM

Quote:

Originally Posted by Parrott

Are your batteries fully charged. If low voltage the fan may not keep the sail switch engaged. For the future, they make a relocation kit to get the board up from the bottom to keep any moisture off of it. I keep a spare board for mine. Sounds like it is going through all the right things to light. Turn it on, when the fan starts you should hear the gas valve click and see if you smell gas coming from the exhaust pipe. If you smell gas and it doesn’t light, then it’s either the igniter or board. If you don’t smell gas then it could be the gas valve. If you do this with the access panel off, make sure to put the exhaust pipe in. I read you are getting hot air for a few seconds. Sounds like the board to me. Check with your dealer and see if he will let you try a board.

I posted here to “make sure the exhaust pipe was in”for testing. Anyway, I still think your board is bad. I’ve seen times you could take a hair dryer and dry them out only to go bad again. I would get Dometic to send a new board and relocation kit. If you ever have to buy a board, get one from Dinosaur. They are much better .

Parrott · 12-12-2021, 07:14 PM

The access panels are known for leaking. Here is how I sealed one up on a Fleetwood I owned. Put a good bead of silicone across the top, sides and middle where the panel hits. Put a layer of Saran Wrap over it. Screw the panel back on but just snug. Let it sit for a couple days. Remove the pane, remove the Saran Wrap and put the access panel back on for a water tight seal.

jetlag · 12-13-2021, 05:04 AM

Quote:

Originally Posted by Parrott

I posted here to “make sure the exhaust pipe was in”for testing. Anyway, I still think your board is bad. I’ve seen times you could take a hair dryer and dry them out only to go bad again. I would get Dometic to send a new board and relocation kit. If you ever have to buy a board, get one from Dinosaur. They are much better .

Quote:

Originally Posted by Parrott

The access panels are known for leaking. Here is how I sealed one up on a Fleetwood I owned. Put a good bead of silicone across the top, sides and middle where the panel hits. Put a layer of Saran Wrap over it. Screw the panel back on but just snug. Let it sit for a couple days. Remove the pane, remove the Saran Wrap and put the access panel back on for a water tight seal.

Yes, most of the testing I was doing had the exhaust pipe off, sure it didn't help. I will call them and see if they will send me one since our dealer is so far away. I like your Saran wrap solution. I presume it is to allow the silicone to cure for a couple of days?

jetlag · 12-13-2021, 09:47 AM

Well, it looks like you are correct. This morning the unit will not fire, only the fan works, and then it will not cut off. I had to pull the fuse to cut it off. What was the board you suggested I buy if Dometic won't replace it? there is only one mobile outfit around here, and waiting to try to get a hold of them. They will pay for the repair, but not the house call .

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