2021 Imagine 2800BH - Furrion heat/AC - Heat doesn’t work without FAN

[uwskier]

I looked at your wire much closer. You have a Cat5 cable, mine is just a plain HVAC cable with only 5 wires.

Not sure what sort of cable it is but it's not Cat5. There are only 7 conductors. Cat5, 6, 6e, etc all have 8. Also not in twisted pairs. Sorry, I'm a networking pro and can nerd out on this stuff all day.

[AZMike]

Not sure what sort of cable it is but it's not Cat5. There are only 7 conductors. Cat5, 6, 6e, etc all have 8. Also not in twisted pairs. Sorry, I'm a networking pro and can nerd out on this stuff all day.

Yeah, I'm a network guy also. I thought I counted 8 in your picture. See below.



Never mind. I see one of them is a string.

[AZMike]

@uwskier, I did some quick research this morning and it seems that the most common thermostat cable is 18/5 and 18/8. I also saw 18/7 like you have. It figures that mine is 18/5!

[Petrovsky]

@uwskier, I did some quick research this morning and it seems that the most common thermostat cable is 18/5 and 18/8. I also saw 18/7 like you have. It figures that mine is 18/5!

I did get my dealer to request the thermostat kit from GD and should pick this up in early May. I agree that some of the thermostat wires have different leads. My home one has a few.....for the gas furnace, the A/C, the actual thermostat, and the humidifier (integrated).

Question: I saw a post saying that GD rarely tacks wiring. Is it too chancy to fish through an appropriate cable with enough wires in it using the existing wire? In my 2600RB my thermostat control is on the side wall in the kitchen and not the bedroom. Also, if I remove the inner cover to the kitchen fan.....would I be able to spot the cable in the roof at that point. The fan is in line with the A/C unit? Has anyone tried this?

[Harvestmoon]

Does anyone know if this issue was addressed by GD and/or Furrion or are they still building them this way for 2023 model year, with the room air temp sensor buried in the roof a/c? We are buying a 2023 XLS 22MLE, which has Furrion everything.

[NB Canada]

Does anyone know if this issue was addressed by GD and/or Furrion or are they still building them this way for 2023 model year, with the room air temp sensor buried in the roof a/c? We are buying a 2023 XLS 22MLE, which has Furrion everything.

Look or feel on the bottom of the wall thermostat
The new one has a bump on the bottom which is the temp sensor

[Rabbit]

From other threads on this subject, new units have the thermostat mentioned in the previous post. But from what I’ve read, the heat now work normally without the ac fan having to run, but when in ac mode the system is still quirky. Apparently the ac still uses a temp sensor in the plenum. IMO a poor design.

[Harvestmoon]

As it turns out our 2023 22MLE has a factory installed Dometic HVAC control. Room temp sense appears to be in the wall control. In gas heat mode with fan set to "auto", the roof a/c blower does NOT run and the inside temperature is well controlled. Only quirk in our particular model we found is that we have to set the target temp a little higher than we would say at home in order to keep a comfortable temp. The majority of the heat comes in at the rear of the coach and that is also where the thermostat is located, so the thermostat warms up before the front of the coach.

[KCAlis]

Here's a mod to the solution. GD sent me the extension harness almost a year ago but I've not installed it due to my hesitancy to punch holes and fish wire.

Then I see from this thread that GD used multi-conductor wire between the control and the AC unit. This is a game-changer. No fishing required!

My revision involves using the extension harness. Essentially, both ends of the harness are grafted on to two of the unused wires in the 7 conductor bundle. One end, with the freeze sensor attached, is plugged into the socket in the A/C box. Plug the uncut temperature sensor into the other end.

I enlarged two of the slots in the wall control base to allow the temperature sensor to protrude below the control. I did not cover it with the kit's screen cover as I want the sensor to be more responsive to temperature changes. I am pleased how the "thermostat" works after this mod.

[AZMike]

Here's a mod to the solution. GD sent me the extension harness almost a year ago but I've not installed it due to my hesitancy to punch holes and fish wire.

Then I see from this thread that GD used multi-conductor wire between the control and the AC unit. This is a game-changer. No fishing required!

My revision involves using the extension harness. Essentially, both ends of the harness are grafted on to two of the unused wires in the 7 conductor bundle. One end, with the freeze sensor attached, is plugged into the socket in the A/C box. Plug the uncut temperature sensor into the other end.

I enlarged two of the slots in the wall control base to allow the temperature sensor to protrude below the control. I did not cover it with the kit's screen cover as I want the sensor to be more responsive to temperature changes. I am pleased how the "thermostat" works after this mod.

You're lucky. Mine was wired with the 5 conductor cable. BTW, Grand Design will send you a new "thermostat" and control box if you request it. Hopefully they are still fulfilling these requests.