2020 GT7 Furnace Will Not Auto-Start

[Dave1957]

We're full-timing in our 2020 GT7 (model 36D7), and continually wake up to interior temperatures in the low 50s. Outside temp at night is anywhere from 32-40. At that temperature, the heat pumps don't even come on. So we're having to rely on the propane furnace.

I can get the furnace to start using the touchscreen panel, and it works fine until the inside temperature is just above the thermostat setting. But after that, the furnace will not start again on its own once the interior temp drops.

On this coach, the furnace switch is part of the living room heat pump touchscreen cluster. I've tried using both the Furnace and Auto Heat settings, but the result is the same. There's plenty of propane in the tank, and the furnace works fine (one time) if I manually restart it on the touchscreen.

Anybody else having this issue? I'd sure appreciate any help you can offer.

[NXR]

Send an email to Nick Hoover nhoover@forestriverinc.com and ask. He handles Georgetown support.

We have real thermostats in ours so I cannot help but I vaguely recall someone saying there was a firmware update for the touchscreen for the HVAC. I also read of several people discovering their bedroom temperature sensor was wired to the front touchscreen and vice versa but that does not seem to be your issue, unless you're running a supplemental heater in the bedroom.

Ray

[kenandterry]

Just a heads up....

Don’t count on heat pumps really working for you below 40 degrees.
You need the furnace with the fan set on “AUTO”.

Other than that, it may be a software problem I guess.

[TimVWulp]

Originally Posted by Dave1957

We're full-timing in our 2020 GT7 (model 36D7), and continually wake up to interior temperatures in the low 50s. Outside temp at night is anywhere from 32-40. At that temperature, the heat pumps don't even come on. So we're having to rely on the propane furnace.

I can get the furnace to start using the touchscreen panel, and it works fine until the inside temperature is just above the thermostat setting. But after that, the furnace will not start again on its own once the interior temp drops.

On this coach, the furnace switch is part of the living room heat pump touchscreen cluster. I've tried using both the Furnace and Auto Heat settings, but the result is the same. There's plenty of propane in the tank, and the furnace works fine (one time) if I manually restart it on the touchscreen.

Anybody else having this issue? I'd sure appreciate any help you can offer.

Hi Dave 1957 try to restart the furnace after it stops running when the room temperature is satisfied do this by turning up the thermostat set point up several degrees to turn the furnace back on right away to see if it will restart. Make sure 12 + volts is available to operate the furnace. Battery’s have enough water in them. If the furnace try’s to restart and goes into a lockout failure condition the furnace is at fault and needs to be serviced.

Hope this helps Tim

[Dave1957]

Thanks guys.

Ray, I just emailed Nick Hoover as you suggested. An issue with the touchscreen firmware makes a lot of sense. I really wish they hadn't put used a touchscreen for that very reason. Too many things can go wrong if that one unit fails. But, I guess we can't escape technology.

Ken, my heat pumps don't even turn on after the outside temp drops below about 48. I know they don't function well in cold weather, but that seems a bit warm for a designed operational cutoff temperature. Either way, that's why we're trying to use the furnace.

Tim, we're on shore power and the coach batteries are showing 13.7 volts. That said, I haven't tried immediately turning up the thermostat setting when the furnace shuts off. I'll give it a try, though I'm not sure of the exact functionality that would test. Seems the same as letting the interior temperature drop slowly on its own, but it's worth a try.

[TimVWulp]

Originally Posted by Dave1957

Thanks guys.

Ray, I just emailed Nick Hoover as you suggested. An issue with the touchscreen firmware makes a lot of sense. I really wish they hadn't put used a touchscreen for that very reason. Too many things can go wrong if that one unit fails. But, I guess we can't escape technology.

Ken, my heat pumps don't even turn on after the outside temp drops below about 48. I know they don't function well in cold weather, but that seems a bit warm for a designed operational cutoff temperature. Either way, that's why we're trying to use the furnace.

Tim, we're on shore power and the coach batteries are showing 13.7 volts. That said, I haven't tried immediately turning up the thermostat setting when the furnace shuts off. I'll give it a try, though I'm not sure of the exact functionality that would test. Seems the same as letting the interior temperature drop slowly on its own, but it's worth a try.

The furnace control board manufacturer has been having a problem with cold soldered connections. This may course the furnace to start when it cold but not when it is hot or warm as the soldered connection lose connectivity.

Hope this helps Tim

[NXR]

Originally Posted by Dave1957

Ray, I just emailed Nick Hoover as you suggested. An issue with the touchscreen firmware makes a lot of sense. I really wish they hadn't put used a touchscreen for that very reason. Too many things can go wrong if that one unit fails. But, I guess we can't escape technology.

Yeah, just because they can does not mean they should.

FR started moving from real thermostats to the touchscreen with the 2020.5 model year, I believe. We have a 2020.0 so we have real thermostats. We also have the infrared remote. At night, if I want to change the bedroom temperature I reach into the nightstand cubbyhole, remove the remote, and I know which button is where by touch. I aim it, make the change, put the remote control back and go back to sleep.

You would either have to get out of bed, walk over to the touchscreen and get blinded by the screen or pull out your phone or tablet and get blinded by its screen. Not a good plan at all. I saw the 2021's and they're the same way. That would be close to a showstopper for me in buying a new unit.

FR needs to discuss backing that change out. It is 1,000% customer-unfriendly.

Ken, my heat pumps don't even turn on after the outside temp drops below about 48. I know they don't function well in cold weather, but that seems a bit warm for a designed operational cutoff temperature. Either way, that's why we're trying to use the furnace.

You likely have the same Atwood AirCommand (Dometic) AC-1511 roof units where each one is a heat pump and air conditioner, and ducted. The specs are that the heat pump will shut off at about 45 degrees outside air temp. This apparently is to keep the unit from freezing up in the colder temperatures.

In actuality, my front heat pump cuts off a few degrees before the back one. The front one seemed to be about 48 degrees while the rear one seemed to be 45. I checked the programming on each one and they were programmed identically so that is probably some difference in the tolerance of the outside air temperature sensor. So yeah, some nights the bedroom heat pump would work all night while the front one was off. Go figure.

On ours, the FURNACE button on the bedroom thermostat does nothing. On the front thermostat, if the heat pump cuts off OR you try to raise the temperature by more than a few degrees, maybe five (?), the propane furnace will kick in. If I actually press the FURNACE button on the front thermostat that makes the propane furnace the primary heating appliance and the heat pump will not engage.

HTH,

Ray

[Dave1957]

Thanks again guys. This is helpful info.

Tim, last night I tried what you suggested. Cold solder joints are a viable explanation, but probably wouldn't explain a really cold furnace not auto-starting in the middle of the night. Still, I waited for it to shut down and then immediately raised the thermostat five degrees and it's fired right up.

Ray, my heat pumps behave exactly like yours. Rear pump seems to trigger around 45 degrees and front pump around 47-48.

I didn't know we could pair a phone with the touchscreen. Again, no documentation from Forest River on this touchscreen at all, not even online. But if I could pair a phone, at least we could restart it without getting out of that cubbyhole bed.

And I agree, the touchscreen would be a deal-breaker on a future purchase. Too many things are controlled exclusively by that unit, including slides, water pump, generator, heating & cooling, and all onboard gauges. A single point of failure for all those systems is a really poor design. At the very least they could have installed some backup switches.

[NXR]

Originally Posted by Dave1957

I didn't know we could pair a phone with the touchscreen. Again, no documentation from Forest River on this touchscreen at all, not even online. But if I could pair a phone, at least we could restart it without getting out of that cubbyhole bed.

Search your phone's app store for Precision Plex

On mine you pair it by tapping the gear in the upper left corner of the touchscreen and then tapping Wireless at the bottom left.

I just do not know if they've added the HVAC controls to their app yet.

And I agree, the touchscreen would be a deal-breaker on a future purchase. Too many things are controlled exclusively by that unit, including slides, water pump, generator, heating & cooling, and all onboard gauges. A single point of failure for all those systems is a really poor design. At the very least they could have installed some backup switches.

There is, actually. Somewhere you have a black panel with the words PRECICION PLEX on it. Mine is in a center cabinet. On the GT5 36B5 it's under the kitchen sink along with the inverter (Yikes!), on others I've seen it over the entry door.

It has a bunch of micro fuses on it. Press the center button to light up the screen. Tap the bottom button to scroll down. My MANUAL CONTROL function is at the very bottom.

Once MANUAL CONTROL is highlighted, press the center button again. That will let you scroll through the items you can manually run from the panel. Select one and press the center button again to run it. Hold the center button if it's a slide or awning.

SI = "slide in"
SO = "slide out"

if you have those designations.

When done, press the left button a few times to get back to the original screen.

BTW, those are micro auto fuses, not the normal mini fuses. You can buy them at an auto parts store as well. You might want to pick up an assortment.

Some videos:

https://www.youtube.com/channel/UCBc...blDL5zg/videos

HTH,

Ray

[Dave1957]

Ray, you absolutely rock!!! I've learned more from you in a couple of posts than anything my dealer (pretty much worthless) and Forest River documentation (not much better) has been able to provide. I have the Precision Plex control unit like yours, over the entry door. I scrolled thru the screens and feel a lot better about the onboard systems than I did an hour ago.

I did find the "Pair with Mobile" button on the touchscreen, but my phone is displaying a bunch of available devices, likely because I'm in an RV park with other RVs on all sides. So, I've asked Forest River to tell me which device to select. Again, a two-page manual for the touchscreen would make a world of difference.

I received an email response from Forest River early this morning, and it appears they have had some issues with the Precision Plex console and the touchscreen, and may need to add a ground wire to my transfer switch. I have to power everything down and remove the Precision Plex panel to see what color of label is on the back. If it's white, I need a new panel and touchscreen. Hopefully they can do that on-site, because this is home for the next few months.

You helped me a lot with my battery control issue a few months ago (resolved) and I just wanted to thank you again for all your help. Hopefully someday I'll be as valuable to this forum as you are.

Dave

[NXR]

Good to hear and thanks for the nice compliment. I learned an awful lot from people here and on other forums such as iRV2 so I just try to give back. Their advice saved me from some mistakes and helped me through some issues.

Just pick a Bluetooth device and try it. If it's not yours you can easily Forget All. It's probably a randomly-generated identifier anyway so there's no way to tell which is yours.

When I saw the Precision Plex panel over the door I thought "I wonder who thought that placement was a good idea?"

In my world, if it's not something I use often it should be hidden out of way. I'd probably hang a picture over that thing or something.

Forest River actually had a small cabinet there and that's what we have. We keep a bunch of things we may need to grab on the way out: traffic vest, flashlight, walkie-talkies, doggie bags, infrared temp gun, etc. It's also where I mounted the sensor for the LevelMate PRO electronic leveling system.

Please update with what you find out. The "add a ground wire to the transfer switch" is confusing if you're talking about the automatic transfer switch for shore power/generator power.

Good luck,

Ray

[rv0083]

Originally Posted by Dave1957

Thanks guys.



Ray, I just emailed Nick Hoover as you suggested. An issue with the touchscreen firmware makes a lot of sense. I really wish they hadn't put used a touchscreen for that very reason. Too many things can go wrong if that one unit fails. But, I guess we can't escape technology.



Ken, my heat pumps don't even turn on after the outside temp drops below about 48. I know they don't function well in cold weather, but that seems a bit warm for a designed operational cutoff temperature. Either way, that's why we're trying to use the furnace.



Tim, we're on shore power and the coach batteries are showing 13.7 volts. That said, I haven't tried immediately turning up the thermostat setting when the furnace shuts off. I'll give it a try, though I'm not sure of the exact functionality that would test. Seems the same as letting the interior temperature drop slowly on its own, but it's worth a try.

I don’t know if this will help but I have a 2021 Georgetown 36D7 that I live in full time in some COLD weather. I disconnected my onboard propane pump and inserted a device so I could use external 5 gallon propane tanks. What I quickly learned was that I was going through propane pretty quickly even with furnace set to 60 degrees the tank would only last 3 days. I experimented and got 6 days by running the fireplace at 80 degrees for 5 hrs at a time with the remote control. The living room thermometer is across from the bathroom door so with the space heater fireplace running, the furnace doesn’t kick on. So if I go to bed at 9pm and set fireplace on max time of 5 hrs at 80 degrees it will shut off at 2am the when the inside temp drops to 60, the furnace kicks on. It could be a thermostat issue also. You are right heat pump inop below 45 degrees

Ps water froze where it entered the RV even with a working heated hose. Took a small portable space heater and put it in the water entry compartment and unfroze the water and the black and gray handles in less than 2 hrs. Don’t forget to put one on other side by water filter. Spec says on water filter do NOT let freeze and it exploded. With your coach plugged into 50 amp you can use the 30 amp to run 2 space heaters and a heated hose

Hope it gets to normal for you

[Dave1957]

Originally Posted by rv0083

I don’t know if this will help but I have a 2021 Georgetown 36D7 that I live in full time in some COLD weather. I disconnected my onboard propane pump and inserted a device so I could use external 5 gallon propane tanks. What I quickly learned was that I was going through propane pretty quickly even with furnace set to 60 degrees the tank would only last 3 days. I experimented and got 6 days by running the fireplace at 80 degrees for 5 hrs at a time with the remote control. The living room thermometer is across from the bathroom door so with the space heater fireplace running, the furnace doesn’t kick on. So if I go to bed at 9pm and set fireplace on max time of 5 hrs at 80 degrees it will shut off at 2am the when the inside temp drops to 60, the furnace kicks on. It could be a thermostat issue also. You are right heat pump inop below 45 degrees

Ps water froze where it entered the RV even with a working heated hose. Took a small portable space heater and put it in the water entry compartment and unfroze the water and the black and gray handles in less than 2 hrs. Don’t forget to put one on other side by water filter. Spec says on water filter do NOT let freeze and it exploded. With your coach plugged into 50 amp you can use the 30 amp to run 2 space heaters and a heated hose

Hope it gets to normal for you

Thanks. It's good to hear from someone with a similar coach. I was all set to have the touchscreen replaced and a ground wire added to the transfer switch, but another FR rep told me the issue is more likely in the furnace control board. I'm supposed to have a service tech out today (if he calls).

It doesn't appear to be an issue with the thermostat, because again this morning we woke up with an internal temperature of 51 degrees. The furnace just isn't working as it should. Hopefully this tech will come out today and get it fixed.

We haven't had any problems with water freezing so far, but our outside temps rarely drop below 32 and when they do it's only for a few hours. I've been keeping a half-tank of water onboard and I shut off and disconnect the hose so we can switch to onboard water when freezing temps are forecast.

[Dave1957]

Well, the repair tech came by yesterday and replaced the furnace control board. Last night's temps dropped into the high 30s, and the furnace worked all on its own. That appears to have been the problem.

Thanks again to the folks at Forest River for helping figure this one out. All in all, we've had very few problems with this coach. I wouldn't buy from the same dealership again, but I'm pretty well sold on Georgetown, especially in the XL/GT7 series.

[Dave1957]

Originally Posted by TimVWulp

The furnace control board manufacturer has been having a problem with cold soldered connections. This may course the furnace to start when it cold but not when it is hot or warm as the soldered connection lose connectivity.

Tim, I was trying to figure out the issue since it had become somewhat intermittent - early in the evening, before outside temps dropped too low, the furnace would work as it should. It was only after the outside temps got into the 30s that it would fail.

That's when the electronics tech in me stepped in and the first thing I thought of was cold solder joints. That would be the opposite of the scenario you described (not working when the furnace is hot), but it still makes a ton of sense. Thanks for the info!

[TimVWulp]

Originally Posted by Dave1957

Tim, I was trying to figure out the issue since it had become somewhat intermittent - early in the evening, before outside temps dropped too low, the furnace would work as it should. It was only after the outside temps got into the 30s that it would fail.

That's when the electronics tech in me stepped in and the first thing I thought of was cold solder joints. That would be the opposite of the scenario you described (not working when the furnace is hot), but it still makes a ton of sense. Thanks for the info!

Hi Dave glad you got fixed. Yes the problem with the cold soldered connections are that the soldered joint was not heated up to the right temp to make the solder flow and properly to make a good connection. When the control board gets warm from quick repeated use the soldered joints lose there connection and the board fails until it cools down. This makes it hard to troubleshoot.

[Dave1957]

Well, we had our furnace control board replaced and for one night it worked perfectly. Then last night, I woke up and it was 64 degrees inside (thermostat was set at 69), so I manually cycled the furnace on. Woke up four hours later and it was 89 degrees and still blowing heat. That's twice it's done that.

Last time, I was able to just shut it off. But last night, I couldn't even do that. It kept running for a solid 15 minutes, still blowing heat. That's way beyond the typical 1-2 minute cool down period. The only way I was able to shut it off was to cycle the 12v system off completely.

So, we're back to square one. I'm convinced it's a defective touch-screen panel, because this coach doesn't have a traditional thermostat. We've got thermo-resistors mounted on the wall that feed temperature info to the control circuit, which I believe is in the touch screen because that's where we set the desired temperature. That's also where the furnace on/off switch is located.

So, I'll be calling FR again today to see what we can do about this. I'll keep you folks posted.

[Dave1957]

Since the weather has warmed up and I'm no longer using the LP furnace, we've found some other thermostat and climate-control issues. I'm convinced the issue is in the touchscreen panel, but the FR rep doesn't agree.

The furnace tech couldn't replicate the problem we were having, but he replaced the control board anyway. As I said in a previous post, the furnace worked for one night and then started acting up again. The problem was somewhat intermittent, so the repair may not have made any difference. We've also had three nights where it just continued to run well past the set temperature, and I woke up to an inside temp of 88 degrees (thermostat was set at 71). On one of those occasions, I couldn't shut it off at the touchscreen, and had to kill the coach 12v system to shut it down.

Now we're having similar issues with the front heat pump. If I use the heat pump in the morning to knock the chill off, the Cool and Fan settings don't work later in the day, even after the heat has been off a couple of hours. The only fix is to cycle the coach 12v system.

Considering that our coach doesn't have traditional thermostats, but instead uses thermal resistors that are connected to the touchscreen, and cycling the coach 12v system fixes every issue, what is the common denominator? Yes, we've got a workaround for now, but it's frustrating and it's not the way this unit was designed to work. More to follow.

[NXR]

Give Precision Circuits a call. The few times I've done that they were extremely responsive and competent. https://precisioncircuitsinc.com/contact-us/

Ray

[Dave1957]

Thanks Ray. Helpful, like always. I'll give 'em a call in the morning.