Our 2017 Lexor TS was the first Pleasure-Way to have the Houghton Belaire 3400 A/C installed so there was a bit of a learning curve for the installation team.
During the installation process we discovered that the control box had to remain connected to the thermostat in order for the heater to work properly. The installer at Advanced RV decided to stuff the large Dometic control box up inside the air plenum. He assured me that it would not affect the air flow but my instinct told me better. Shortly after I returned home I got to work to fix the issue.
I removed the inside portion of the A/C and pulled the control box from the plenum. I cut the connector with about three inches of wire from the end of the harness, capped the wires, coiled up the remaining harness and tucked it into the ceiling next to the A/C cutout. I then compared the connector wires with the wiring in the utility cabinet and found the other end of the harness.
I removed the thermostat and disconnected the harness connections.
I fished a piece of 18 gauge 3 wire thermostat wire up from the utility cabinet and connected three wires to the thermostat and then connected those three wires and the control box connector to the other end of the harness in the utility cabinet as shown below.
I then mounted the box to the wall of the cabinet.
The air flow definitely improved and I finally felt like the installation was complete!
Very nice!
Thank you Randy!
This was very helpful yesterday! We had the Houghton 13.5K with heat pump/air conditioner installed yesterday, and this article was a high alert about that control box for the Dometic and the need for it to remain to control the furnace. The installer moved it over to the passenger side cabinet where the spouse’s clothing are stored. It was still a bit difficult to fish even though was only about 30 inches. He cut the connectors off, fished, and reconnected the connectors. So glad I could warn him about this box and the need for it ! 🙂 Thanks once again for blazing the path 🙂 The Dometic thermostat says E5 which is an open Freeze sensor which disables the Air Conditioner control. I may leave it open or perhaps short it (?, resistor?)
– Cool day here in New England and I have the unit on Auto Heat on a 15 amp circuit. Working nicely. A quick db of the air conditioner yesterday was 57 db vs the 70 db of the Dometic. I will measure more carefully and post in Facebook
You’re welcome Mike! I hope you enjoy that new decibel level as much as we do. Our thermostat is not showing an E5 with our wiring configuration. You may be able to clear that up by replicating the wiring in the photos. Please let me know if I can help with clearer images or any additional info.
Bob,
Thank you for the great information. We are about to make this plunge with our 2017 PW Plateau TS and will definitely be speaking with installer for our Houghton about the control box. I did have a question though, and please forgive my ignorance.
Would it be possible to run a thermostat control wire from the furnace to a two wire heat only thermostat and do away with the control box?
It looks like it would be short run and allow you to use a battery powered digital one like Honeywell’s. From the research I have been doing — it does not look like the furnace is powered off the control box. I am sure that I am missing something though and I greatly appreciate your thoughts and insight. Thanks
Hi Jeff,
I hope you enjoy the Houghton as much as we have.
The current Dometic thermostat is designed to work with the control box but you can certainly install a new thermostat and bypass it. The wiring instructions for the heater and thermostat are on page 7 and 8 of the Atwood manual at the link below.
Atwood HydroFlame Installation Manual
There are a number of creative ways to use modern 24V home thermostats with transformers and relays but the simplest solution would be to replace the current unit with a manual heat only 12V model like the one below.
Atwood Analog Heater Only Thermostat
I found it just as easy to simply relocate the control box and keep the current thermostat in place since the connection to the heater had to be rewired for a new thermostat too. One other advantage to relocating the control box is that everything is still in place if it ever becomes desirable to install a different A/C unit that can use the heat and cool thermostat once again.
One other note on the Houghton. I worked with the folks at Sensibo to add the unit to their list of supported devices. We’ve been using their Sensibo Air controller for the last few years. It’s been a nice add on that provides more convenience and control from an App on our iPhones.
Sensibo AirQ
I hope this info helps and that the installation goes well!
Bob
Thank you very much Bob — it definitely helps
You’re welcome Jeff.
Bob would you please email me on how you set the sensibo up with your Houghton
Hi Ricky,
I worked with Sensibo to have the Houghton Belaire added as one of the preconfigured system options. It was necessary to remove the Houghton remote from the vehicle during the initial setup. When it was present it interfered with the on/off setup step.
Bob.