thermostat help please

[Thefoxx77]

Hello im having a issue with my furnace in my travel trailer not turning on. I have a arwood furnace and a dometic ac and dometic thermostat on the thermostat i set it to ac it comes on right away i switch it to heat and i get nothing no fan no ticks nothing. So i go to my furnace and there is 2 blue wires marked thermostat if i put the together the furnace works perfectly. I have a 2013 layton joey park model 37ft the thermostat is the digital version 3 button style. Anyone know what this could be. I checked all connections at thermostat and furnace and at the control box they all seem fine.

[time2roll]

https://www.campingworld.com/dometic-standard-ct-thermostat-black-88513.html

This is the basic one. I see some have bluetooth now if that has features you want.

https://www.rvupgradestore.com/Dometic-Heat-Cool-Bluetooth-Thermostat-BLK-p/40-0001.htm

[Thefoxx77]

It the click style buttons and small lcd screen

[time2roll]

Probably defective thermostat. Is it the old style with click buttons or the newer capacitive touch? The older ones seem to have issues.

[prichardson]

The connections to check will be at the control box. With a volt meter (DC volt setting) You should get 12volts between the two blue wires on a call for heat. If none since the system works on cool the problem is likely the control box. If voltage the problem is in the wire between the furnace and control box.

[Thefoxx77]

Dometic 3313189.000 Single Zone LCD Thermostat and Control Kit it worked perfect last season just started not working last week. The wires in the thermostat are red blue and white red is marked +12v blue is comms and white is -12v do you want me to che the blue wire at the thermostat or the 2 blue wires at the furnace. Thanks for the replys i really appreciate them

[Wishbone51]

Use a resistance meter on the connection where the blue wires go in the thermostat and turn it on. If there is no connection, then the thermostat is bad, especially if you say it works when you touch them together.

[prichardson]

Make and model of thermostat? Did it ever work? Could be a break in the wire between the furnace and thermostat, wired wrong, or bad thermostat.