Houghton we have a problem-furnace thermostat

[Hawk-ination]

Reaching out for a few suggestions from suppliers as we speak but Dometic has said that the furnace can no longer be controlled by the wall unit in our 2014.5.

Although the Houghton has a heat pump, I’m not keen on the idea to eliminate the Atwood furnace all together. Has anyone eliminated or bypassed the Dometic thermostat or have any idea on if this is possible? I have found an analog thermostat but not thrilled on taking one step back on the technology, although if it would work, we may have to settle on that idea.

I have yet to consult with our RV shop and such, but just thought I’d pick the brains of the experts on this forum, or see if there’s anyone on that has had their AC unit replaced by a Houghton and/or by Advanced RV and see if there’s a work around.

Any ideas?

[Pahaska]

Originally Posted by Hawk-ination

Reaching out for a few suggestions from suppliers as we speak but Dometic has said that the furnace can no longer be controlled by the wall unit in our 2014.5.Any ideas?

The Dometic thermostat controls the AC through a 4-wire telephone cord through coded commands. Similar to a USB connection. There is no way some other brand AC will work with the thermostat. Especially an AC with a heat pump.

The Dometic AC is natively a heat pump and the thermostat issues a command to switch it to AC mode. I had a 2005 A/S trailer where the AC kept coming up in heat pump mode. Not nice when it is 100 degrees outside. After two new AC units and a new thermostat, I traded off that trailer, still under warranty, to a dealer for a new 28 Classic. Turned out that a defective microwave was inducing transients in the telephone cable and burning out the solenoids that change to AC mode.

It is going to require a thermostat that is compatible with the new AC and is heat pump enabled.

[Hawk-ination]

Thanks Pahaska, I appreciate the advice. Sorry to hear you had back luck with your trailer like that. I know we’ve had some odd things happen where the AC fan will kick on with the furnace. Found out shutting it off and back on a few times seems to clear the quirk when it happens. I had a lot of problems last year until I cleared our thermostat a few times, too. It seemed like it got stuck in program mode. Sorry your unit wasn’t so easy to clear and took a trade off to remedy the situation.

Well, I just got a phone call from the owner of Advanced RV, Mike Neundorfer himself. I think I missed half of what he said just because I’m still shocked he would personally reply to an email like that! Still feeling a little special... .

So it sounds like they hook the furnace up to the new AC unit controller which is operated by a remote control (that comes with the Houghton unit). As I suspected and thought I understood during research, they opt not to have the heat pump included on their AC units due to efficiency I believe he said.

So one step closer but pretty much confirms my thoughts that it would be best for us at least, to have a shop wire it up so it’s done correctly.

He also said to have it leak tested because there is a chance it can be done incorrectly. Mike did say that they machine a roof adaptor to mate the AC unit to. I think I have found a source to help with that problem, I just need to connect with the vendor yet.

Good information he shared and think it says a lot that he was willing to share their intellectual property. They get my endorsement for good customer service.

Still open for suggestions or comments though. It’s not probably a common thing to do but I’m hoping there’s maybe a couple out there that have done something like this.

[wachuko]

Great insight!

Thank you for keeping us updated on the progress!!

[janesnest]

Our Dometic thermostat, in our brand new Nest, switched to Celsius after our first trip out. We have no idea why. My husband frequently works in Europe so we know how to easily convert, but it’s annoying. Looked through all their instructions and can find nothing about a Celsius option. Our air conditioner switched on a couple of times on a very cold night, but like someone said above, toggling back and forth a couple of times got it back on track. We finally get in for warranty work on November 20, so hoping these issues, with many others, can be fixed!

[Pahaska]

Originally Posted by Hawk-ination

Does anyone on the forum have enough electrical knowledge and want to advise on helping wire up the furnace to the remote?

I see no need to do anything with the furnace due to the new AC. The AC can be controlled by the remote and the furnace controlled the way it has always been.

[Hawk-ination]

Unfortunately, everything I’ve been told is the Dometic thermostat will not function without the Dometic AC unit. There is a work around to wire the board into the remote but I do not have enough knowledge to know off hand how to wire it although I’ve been studying what I can come across online.

Although I don’t believe this would fix the issue at hand, it’s an interesting product. Wireless thermostat to power AC and heat by your phone.
https://www.microair.net/products/ea...32199143555156

[Pahaska]

All it takes to run the furnace is a cheap thermostatic connect the two blue wires. In my former Classic 28, I mounted one on the side of the AC shroud so thatI could run heat pump and furnace together when the heat pump was not quite enough.

Connect these wires at the AC or pull out the furnace to get access to them.

[orlik]

Originally Posted by Hawk-ination

Unfortunately, everything I’ve been told is the Dometic thermostat will not function without the Dometic AC unit. There is a work around to wire the board into the remote but I do not have enough knowledge to know off hand how to wire it although I’ve been studying what I can come across online.

Although I don’t believe this would fix the issue at hand, it’s an interesting product. Wireless thermostat to power AC and heat by your phone.
https://www.microair.net/products/ea...32199143555156

We had the Houghton unit installed in our 2017 in June by AVR. My remote does not control the heater just as I was told after installation. I have to use the Dometic thermostat on the wall to use the heater. Not sure how you can use the remote to control the heater unless a receiver of some kind is installed to switch the heater on and off. I know you talked with the owner of ARV but the guy that was in charge of Houghton installs was a man named Frank. Sorry, don't know his last name. Perhaps you misunderstood him or he was wrong, or your rig's AC unit is different from mine. I suggest you call ARV again and ask to speak to person in charge of the Houghton installs and just confirm. Nice folks there, I'm he would not mind talking to you.

[Hawk-ination]

Good to know Orlik and appreciate your information. I did speak to Frank after talking to the owner/President. I’m not sure if they’ve found a different way to make the remote work since your install or he just wasn’t taking the time to talk it all through but Frank told me straight up the wall thermostat would not work any longer. Odd yours does work and he told me differently. Although I did get different info than what you are saying, I do not disagree with you at all. He may have not felt like discussing in depth or maybe misspoke.
I’d actually prefer to keep the wall thermostat to make the furnace work so hoping we can wire our project up to work like yours.

Long day of working to get the Interstate ready for storage and wrapping up outdoor things while we are having a fantastic but certainly unprecedented warm weather streak before the reality of fall hits next week. Will come back to this as someone else had talked to Advanced and I think got similar info as me. Not sure that’s super important though as if your thermostat works, like I said, I’d rather figure out how to power it up and keep that as the control for the furnace. Great to know, gives me hope I can find someone with the answer how to make this work and help us get it powered up here instead of driving half a day to make that happen. Pahaska might just be totally right and there’s not much to getting it to power up and work correctly.

I’d just like to figure it out with the unit on the ground instead of struggling to power everything correctly and have issues that could have been avoided in the first place. Would feel better if I had someone knowledgeable to consult with around the area too, but I haven’t connected with the right person yet. I have much more hope we can make it happen knowing yours works though Orlik, so thanks again for that input. I think you will help out at least one more member who needs to hook their furnace up, too. Many thanks.

[InterBlog]

Originally Posted by Pahaska

All it takes to run the furnace is a cheap thermostatic connect [with] the two blue wires. ....

This is true. I don't know if the truth of it will have any impact on the OP's specific predicament described in this thread, but on its face, it is true.

For example, the 9-volt battery-operated Honeywell shown below was thirty bucks, and I installed it to replace the antiquated Atwood that Airstream had originally installed.

The only problem with this arrangement is that the Honeywell is a cheap residential-grade device, and it can't stand up to the rigors of vanlife or the chronic humidity of the deep southern United States. I have to periodically replace it with a new unit because its electronic brain fails repeatedly, probably due to tin whiskers.

[antiguasky]

I had the first Houghton AC installed by ARV a few years ago on on a vehicle with a Dometic AC/Atwood heater. At that time we discovered the issue that you're experiencing now. The solution was to place a jumper in the control box to fool the thermostat in to thinking that the AC was still present. ARV placed the control box back up into the Houghton's air chamber. I later relocated it to reside near the heater. Please let me know if your issue is still not solved and I'll be glad to open the box and take a photo of the jumper.

[InterBlog]

Originally Posted by antiguasky

I had the first Houghton AC installed by ARV a few years ago on on a vehicle with a Dometic AC/Atwood heater. At that time we discovered the issue that you're experiencing now. The solution was to place a jumper in the control box to fool the thermostat in to thinking that the AC was still present. ARV placed the control box back up into the Houghton's air chamber. I later relocated it to reside near the heater. Please let me know if your issue is still not solved and I'll be glad to open the box and take a photo of the jumper.

Wow - now that's what I call a strong debut post. Welcome to Air Forums.

[Hawk-ination]

TNice, thanks for the offer antiguasky. I might take you up on the offer. I’d guess Orlik might be happy also if they want to get their furnace to operate also.

Nice of you to go out of your way to help me out. I really didn’t want to tackle such a major project without the work around. I’m sure I’m making my significant other nervous enough ripping a perfectly good AC unit off the roof as is!

We have a lift lined up and it’s in the garage where I can take it off. Just need to get the unit painted and then see what a nightmare I’ve created for myself. Or not. Hope not. Thanks again and much appreciate. Welcome to the group!

[orlik]

Originally Posted by Hawk-ination

TNice, thanks for the offer antiguasky. I might take you up on the offer. I’d guess Orlik might be happy also if they want to get their furnace to operate also.

Hawk, my heater works fine. I still use the original Dometic thermostat on the wall. ARV could have modified something it to make it work but they did not tell me. They just told me if I want to use the Atwood heater continue to use the wall thermostat.

[Hawk-ination]

Oops sorry, it was another member that was having issues with the furnace not working after switching out their AC unit.

Have to admit to having some quarantine brain. Need to get out camping and have a change of scenery!

[Hawk-ination]

Antiguasky, thanks for your offer and I did send you a PM to connect. Welcome to the group by the way! So thankful to all the members for sharing what they know, it’s made a lot of upgrades or fixes so much easier.

My apologies once again Orlik, to many sleepless nights, as I shouldn’t have thrown your name in a post like that.

Getting to the point where I’d like to figure out the solution before launching into disaster. I mean success!

To any of you who haven’t taken off the thermostat, it does have a communication cord running to the back, so that might complicate an easy swap for anyone now knowing how that works. I would be one who would be a bit lost, but have asked for help from a friend who understand wiring better than me. We’ll see if we can’t get it figure out with the help of all of you. Thanks again!

[GAAirstreamr]

Looking at changing out our Dometic PenguinII in our 2014.5 Interstate Lounge for the Houghton unit this winter. Was there any headway made on straightening out furnace? We do use the furnace almost as much as the AC, and I wouldn't mind using that thermostat just for heat.

[Hoonanea]

Originally Posted by GAAirstreamr

Looking at changing out our Dometic PenguinII in our 2014.5 Interstate Lounge for the Houghton unit this winter. Was there any headway made on straightening out furnace? We do use the furnace almost as much as the AC, and I wouldn't mind using that thermostat just for heat.

Some time has passed and wondering if you moved forward with your plans to replace the Dometic PenguinII? I have my Hougton Belaire 3400 on a pallet in the garage waiting for some help to be here to get the old one off the roof and the new one on. Might be May or even July before that happens.

My plan for the Atwood gas furnace is to go very low-tech and use an inexpensive thermostat to control only the furnace -- zero integration with the new A/C unit. I have a Dometic 2-wire thermostat ready and my brother made a nifty backer plate to mount it on using his 3D printer. This will cover the mounting screw holes of the Dometic CCC2 thermostat.

A little extra work will be involved to run two wires to the furnace to connect to the two blue wires. I don't think that will be too much of a challenge. What I'm going to need help with is just where to intercept those two blue wires as I can already see they have multiple connection points in the furnace compartment. I'll hand the wiring diagram to my brother and he'll figure it out.

As for the A/C unit, I think I need to order RecPro's thick roof air duct extension based on a post in a different thread (from @PizzaChop, perhaps?). He made an extension out of aluminum. Not sure I'm handy enough to do that so I will just order the extension and have it on hand in case I need it.

[Rocinante]

It's my vague understanding that if you yank the right control board out of the old Dometic AC unit and leave the existing thermostat connected to that, you should be able to continue using that thermostat to control the propane heater. Of course, you control the new AC unit via the hand-held remote. Then, the AC settings on the Dometic thermostat do nothing but talk to the old bit of control board that gets shoved somewhere in the ceiling out of the way, along with the new AC unit. Supposedly pretty easy, with no re-wiring needed for the propane furnace control. Might be worth investigating?