Dometic Furnace "Clicking"

[Firewall]

Problem - When calling for heat the Dometic Air Conditioner clicks for about 30 seconds when the temperature reaches the set point. This is not a problem with the furnace, it runs and heats fine.

This subject has been covered often and I have read many posts about the issue. It appears that to solve the issue a dometic thermostat can be set for a differential of either 1 or 2. Two allowing the temperature differential to get rid of the annoying clicking in the air conditioning unit. My issue is I have the In-Command system so there is no visible or wall mounted thermostat to adjust.

I contacted In-Command and here is their response;
"Thank you for contacting ASA Electronics. iN•Command is not a thermostat. We simply allow the user to send a request of a temperature to the thermostat (produced by Dometic) in the ceiling. This component is their gateway and is what controls the furnace, AC, and fans. It also reports the temperature to iN•Command. It is my understanding that this tolerance cannot be adjusted through their single zone control box, but you would want to check with Dometic on this."

So my question - Where did they hide the thermostat/gateway and is it adjustable?

[chuckster57]

Just a WAG, but I’m willing to bet you have a remote thermistor mounted on the wall somewhere and the “thermostat” is in the control box. Where the control box is is the question. Maybe it’s in the return of the AC or on the roof under the cover.

We don’t sell/service units with in command so I’m not familiar with it.

[ChuckS]

Since you have the In Command system the communications to and from air conditioner, HP, and furnace are all across a single 4 wire telephone cable..

The electronic control box mounted inside the roof top air conditioner or air conditioners ... if you have two AC units there are 2 electronic control modules in the system controls all demands for cooling, HP if option available, and furnace..

There are NO differential set points...

The BCM from in command sends your digital to analog selection up to control box on Zone 1 ... Zone 1 is main LR unit.. Zone 2 if installed is usually bedroom.

They are wired together via 1 telephone cable and both communicate to and from BCM via this cable

Their will be 1 or 2 “remote” wall mounted temp sensors inside your RV... these sample the inside temp and compare to the temp you have selected via your in command display unit

The furnace is also tied into Zone 1 control module and it also receives its on,off, and temp settings from zone 1 module and In Command tablet

The hierarchy of the entire system is the “CANBUS” data sent back and forth across all those 4 wire telephone cables...

If in fact the “clicking” sound you are hearing is from up above it will be something on that Zone 1 control box module. It sounds like a solid state relay may be in question on that board...

[ChuckS]

This is a typical control box for Dometic Brisk air I unit.. not sure what unit you have.. but it gives you an overview of control wiring to the module

Circled in yellow are two solid state relays. Red marks indicate typical connections for remote temp sensor and RJ11 phone line that runs down to in command system as well as another plug that would run to furnace and one more to second roof AC control module if installed

[ChuckS]

Typical In Command system wiring from Display Commander to BCM up to roof AC units and furnace

[Firewall]

There are NO differential set points...



Thanks Chuck, that's what I was afraid of!

The clicking only affects guests on the couch which is right below the A/C unit. The front A/C does not click, so I sleep well!

[Adam450]

In reading so far. The loud clicking has not been resolved. Is that correct?
Thanks Adam