Heat/AC failure in rigs with inCommand

[mikec557]

I don't know if this info is useful to you or not, but we just camped two nights in below freezing temperatures... not necessarily by choice. We were driving back to Sun City West from Texas when a cold front moved in.

Temps were expected to be low 20s to high teens the first night and low 20s the next night, Kerrville TX and Las Cruces NM respectively.

We were concerned the water lines in the belly would freeze. I set the InCommand to 70 degs throughout the night, both nights. Everything worked as expected. I should add that during the first day the inside RV temp during the day was in the low 70s using just the electric fireplace, using the InCommand HVAC only at night.

The morning we left after the first sub-freeze night, it was mid 20s. The day was supposed to be very cold for a long time. I decided to "run" the furnace while driving down the road. I set it to 55, the lowest temp the InCommand has, and figured it will work or it won't. It worked perfectly. And, no frozen water lines. Did the same the second day of driving.

Maybe all this worked because the temp inside the camper was never too "low"?

BTW, ours is a 2020 Cougar 26RBSWE (built 10/2019).

[LHaven]

Originally Posted by mikec557

Maybe all this worked because the temp inside the camper was never too "low"?

The original inCommand/Dometic gateway issue was that the furnace would fail to start if the cabin temp was <50°, and the A/C would fail to start if the cabin temp was >100°. When the cabin temp is temperate, neither of these issues would show up. In both cases, spoofing the thermistor with artificial heat or chill can end-run the issue.

I'd be really spooked about running the furnace while on the road, but in your case, I'm not sure I see an alternative. I would definitely be willing to turn on the tank heaters, though, as I'm pretty confident they're DC.

[FullTimeAdventure]

I have a 2021 Montana and I think I’m having the same issue. It’s in the 30s outside and the other day the panel showed 0 degrees ambient temp and furnace would not come on. It would immediately switch off after I turn it on and nothing would happen.

Now today, the ambient temp reads 41 and will not move however the furnace will turn on but continuously run because it thinks it’s 41 inside. Very strange.

I’m full time in the rig and have been stationary for the past 6 months so the temp inside have always been maintained but a few days ago I started a move across country and for the first time since I’ve owned it the inside temps dropped close to freezing while on long travel days. Not sure what to do from here. I have the Coleman AC units with the whisper quiet ducts so I have no idea where the gateway is. I looked under the little filters and there’s nothing. Maybe on the roof under the shroud?

[travelin texans]

I'd be really spooked about running the furnace while on the road, but in your case, I'm not sure I see an alternative. I would definitely be willing to turn on the tank heaters, though, as I'm pretty confident they're DC.[/QUOTE]

If the temps were to be cold enough I would run the furnace while traveling, never an issue.
Also every mile of travel with all the rvs I've owned had the fridge running on gas, also never an issue.

[JRTJH]

If I have my facts right, the 2021 Montana High Country and the 2021 Montana DO NOT have In-Command. It is an option, available in the Montana series ONLY with the Legacy Package. So, looking at a Montana, if it has a "molded fiberglass rear panel" it likely has the In-Command system. If it has a "flat aft panel" then it probably has a conventional thermostat and not the In-Command "limitations".....

[Proud]

Here is the bulletin from Dometic. I have the same issue on my recently purchase 2019 fusion 369( no known warrantee) . I haven’t contacted Dometic yet but I was wondering others experience. Is it a recall item? Can I expect the part(s) for free? Do all three gateways need to be replaced if I have 3 ac’s? Will they provide the parts for do-it-selfer or shop only. ( the gateway box is over 100 bucks if Dometic doesn’t back)
Thanks in advance, Jp

[LHaven]

Thanks for the bulletin. I never had a copy of that.

You don't say what year your trailer is; I gather from your comment that you are not the first owner. (Please fill out your "User CP" so this information will appear in your postings.)

Your warranty for such stuff from Keystone is only one year.
Dometic warranties, on the other hand, tend to run two years, which is nice.
If there is a "service bulletin" on this issue, it's sort of like (but not officially) a "recall," so Dometic may do it for free or may cut you a deal on the fix... you'd have to call them and ask.
In any event, your unit would have to have inCommand, as it's not an issue otherwise.

[Proud]

I found some more info on subject, see attached.
Also hoping someone can answer questions I stated above. Thanks

[LHaven]

I think all the questions that remain unanswered are questions about what Dometic is willing to do for you, and the only way to get answers to those is for you to call Dometic and ask.

You haven't yet explained why you think you have no warranty on a 2019 trailer.
Don't forget to fill out your userCP signature.

[JRTJH]

Originally Posted by Proud

I found some more info on subject, see attached.
Also hoping someone can answer questions I stated above. Thanks

If the warranty is still valid, after one year, Keystone no longer processes warranty claims (it's in the Keystone Owner's Manual) and the responsibility to contact the item manufacturer for warranty repairs falls on the dealer or the trailer owner. As posted by LHaven, the only way you're going to find out what Dometic will do for you, in your situation, as the second owner of their product, is to contact them and ask how to "process a warranty determination and a warranty claim"... What they did as a "good will gesture" or as an "oversight that slipped through as an approval" for someone else won't do you much good.

You need to talk to Dometic and see how they want to handle "your situation". If their answers are favorable, then great. If they tell you no, then you're likely going to be on your own. As a second owner, if there was no transfer of warranty (also required in the Keystone Owner's Manual) then you may find that omission gave everyone an "out to deny any future claims" or they may register the remaining warranty (if there is any) and process your claim....

Talk to Dometic to get the answer. Speculation from other's won't be a binding response on whether they approve/disapprove a claim from you. Every situation brings a different potential to move to a different branch in the "approval logic tree worksheet"...

[Proud]

So I have follow up information. Keystone did replace the gateways (all 3) by mail directly to me after a little back and forth emails. Dometic also offered to replace if I took trailer to authorized service center. Seems like a logical outcome with the company literature that is out on the web admitting the engineering programming error.
I’m just glad we have a forum like this one, to make this info public knowledge. I can’t imagine the frustration of trying to turn on hvac below 40 or above 100 and nothing happening. Thanks, Jon

[LHaven]

Originally Posted by LHaven

After ten minutes or so, it became obvious nothing was heating up, so I dressed up and ambled out to the trailer. Turned the furnace on from the display panel. Click from the Dometic gateway box, then... nothing, no pre-heat fan noise, nothing. Did it a few times. Checked the range to make sure the shop hadn't valved off the propane. Finally set up the ceramic heater for the night, turned on the tank heaters, and went back to bed.

An update, for the record:

Temps were scheduled to reach 31° again in the wee hours Wednesday (2/23). When I got out to the rig, the cabin temp was in the mid 30s. The furnace again refused to even attempt to start. I huffed into the thermistor to raise the reported cabin temp above 55°, and turned the heating system off and on again, but it changed nothing. Again, I left the ceramic heater, the tank heaters, and the water heater on overnight to combat the freeze.

I have a ticket out to ASA to see if they have any ideas or advice.

I spend a good hour or so disassembling, cleaning, re-greasing, and reassembling our little ceramic cube heater, as it looks like we may be relying on it more than expected.

[LHaven]

And some clarification from ASA Electronics, the inCommand people:

I've attached our HVAC explanation guide which shows the gateways and explains how the gateways are the thermostats and iN•Command is [only] a window to the thermostats...

iN•Command is not reading the temperature of the room. It is the gateway that is connected to the wall sensor, and then reports that temperature, using our display...

Dometic's version of the gateway did have issues with firing the furnace below 40° and firing the AC above 90°. This should have been resolved with the replacement, but we cannot tell you how to confirm this...

So it sounds to me that rigs with that model Dometic gateway would have shown this bad behavior regardless of whether they were attached to inCommand or just a conventional thermostat. Possibly this model of gateway was installed only in rigs that were slated to be outfitted with inCommand, which is why the problem shows up only there and thereby gets associated with inCommand.

[LHaven]

OK, now a question.

I took a photo of what I always thought was my gateway box, inside the A/C air intake cavity, only to find out it is exactly the same box I had before the replacement, and it says "ReLay_ControlV4.hex" on the bottom. The web sees to agree that this is a "relay box" and so probably not the gateway.

Though I can't locate any canonical diagrams for my own unit, all the gateway positioning diagrams I can find for Dometic gateways have them located somewhere inside the roof cowl, which I'd have to pull off to inspect what model I have installed. Is that accurate? If so, I think I'm going to abandon any idea of doing that.

(D'Oh! Diagrams for my own unit are right there on the reverse of the Tech Bulletin... and that's exactly where the gateways are.)

So I shipped off a complaint to Dometic and I'll wait to see what they say.

[LHaven]

Dometic's response was basically that they can't debug a problem over email, and I should have my dealer look at it. That would be a waste of time, as the problem is intermittent and I will bet you a donut that the dealer will never be able to see it happen.

So I'm out in the trailer tonight cleaning up and getting ready for a trip. It's 60 outside, and 61 inside, and I set the furnace to 68, and once more nothing happens. I can hear a click from the relay box in the ceiling air conditioner, but the furnace doesn't even try to turn over. I applied the suggested fix from the Dometic service bulletin for the factory gateway that had the original problem, which is to set all the controls for the desired operation, then cut power to the air conditioner for a couple minutes, and when you return power it should do the right thing. But that didn't work either.

So I'm about to leave on a trip knowing that my furnace is almost certainly going to do me dirty. I can't even do simple board diagnostics from the outdoor hatch, because my model doesn't have an outdoor hatch – everything is buried deep under the refrigerator. I am just bummed having quality problem after quality problem with this rig.

[LHaven]

I just had a thought – I removed power from the air conditioning unit using the circuit breaker, but the furnace is a DC device, which implies that the gateway inside the A/C cowl on the roof has to be a DC device as well, so I should've pulled some fuse instead. I once mapped out which fuses went where, but I never identified any for the furnace, inCommand, or stuff that I can't even see under the air conditioning cowl on the roof. I suppose more study is required.

[MarkEHansen]

One way to remove the power would be to pull the negative lead from the coach battery.

Are you sure the problem is not the control board in the furnace? The wires for the furnace go through the outside fridge access on your trailer, so you can inspect power at that point. If you have power on the 12V lines and show 12V on the two thermostat lines and the furnace still doesn't light, then it seems like the problem is in the furnace itself - likely the control board.

I can provide more details about this if you want.

[JRTJH]

Often times there's a fuse in the "digital Dometic thermostat" that will keep a "memory charge" on the control unit. Sort of like using a 9 volt battery pluggedn into a cigarette lighter socket to maintain a car's memory system during battery changeout...

If you want to "remove power from the control circuit" the best, most effective way, is to unplug from shore power, then remove BOTH battery terminals and then, to be sure, short the battery terminals together for 1 minute. I know that's considered "overkill" by most people who work on these things, but I've seen many (way too many) when someone has a battery backup in a bedside alarm clock or has a 12 volt "jumper/charger/air compressor" plugged into 12 volts to recharge that device and when you disconnect the battery on the trailer, that jumper/charger backfeeds "just enough power" to keep the memory circuits charged...

So, to "remove all power from the system" unplug shore power, disconnect BOTH battery terminals and short them together. Look at your "sweep second hand on your watch" and leave the terminals shorted for a full minute.

Then, retry your furnace controls.....

[LHaven]

Thanks for the tip on killing all possible power. If it was a one time fix, I'd do it right now, but Dometic says it has to be done every time the gateway balks, and it isn't a permanent fix for the problem.

As for debugging the furnace through the refrigerator port, it was a good idea, but I don't see that I get any access to the furnace by going in that way. There's a partition, and the furnace is under it. (Image)

On the bright side, if the furnace gets 100% balky, I can have my dealer look at it when I bring it in to swap the propane regulator, and he'll be able to see it fail first time.

[MarkEHansen]

Originally Posted by LHaven

Thanks for the tip on killing all possible power. If it was a one time fix, I'd do it right now, but Dometic says it has to be done every time the gateway balks, and it isn't a permanent fix for the problem.

As for debugging the furnace through the refrigerator port, it was a good idea, but I don't see that I get any access to the furnace by going in that way. There's a partition, and the furnace is under it. (Image)

On the bright side, if the furnace gets 100% balky, I can have my dealer look at it when I bring it in to swap the propane regulator, and he'll be able to see it fail first time.

Sorry if I wasn't clear. On the left of that cavity are the 4 wires going down to the furnace: +12v -12v (GND), +Thermostat and Thermostat.


You can check these wires for power. If they have the correct power on them and the furnace doesn't light, the problem is with the furnace, not the gateway or anything else.


The +12v feeds the furnace controller. Of the two thermostat wires, one comes from the furnace with +12v to the actual thermostat (iN Command in our case) and when the thermostat is calling for heat, it will send +12v back on the other thermostat wire.


So, if you check those wires and find +12v on the power and both thermostat wires, the furnace should kick on.


You'll find the wires on the left side of that cavity. There will be a hole going down to the furnace from there. You see those 4 wires come up through that hole and then connect with 4 other wires, bundled together with a zip-tie and held in place with some spray foam. Just pull the bundle from the foam enough that you can get VOM probes in under the crimp connectors.


Attached is a picture with the wires pulled lose from the foam and about to be pulled down through the hole (I replaced these wires with longer ones so I can pull the furnace out of the cavity when I need to do repairs/maintenance):