We're somewhat isolated here at the beach with very slow internet and our Cousin is having trouble with her furnace. She has a two year old rig and the heater won't come on. I found that the Dometic TS #3313189.023 is a three wire and I know from nothing about them. I know where the control panel is and thought I could check the output to the furnace for twelve volts but after that I'm lost if there is no 12 volt out put. She really doesn't want to drive home and have it fixed so I thought I'd check if it's the furnace or the thermostat/control panel.Is there some way to check if the Furnace feature of the TS is working? All the other functions work. I thought I'd reinitialize the control panel today but other than that is there anything I can check in the TS system. I've verified that there is power to the furnace. I just have my little Fluke DMM so it's just a basic DMM.If the furnace is getting 12 volts, I can troubleshoot that but not the electronics of the TS.

The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.Here's how to put it in diagnostic mode:http://bryantrv.com/docs2/docs/singlezonediag.pdf

Is that the little 3" square 'single zone'Controls one heater one A/C unitMy uncle has that in his new class B, (traded off his Thor Serrano)Seems to be a troublesome design, and it has a slow responseTry changing mode to heat , run the temp up to something like 80 or 90(for testing)Then set to ON do not set to autoThen wait , could take two minutes or more to come onThere was another thread few days ago, somebody wanted to replace itOptions are limited , it's a proprietary digital systemI saw a schematic posted someplace of the control box wiringMaybe it was from Chris

Chris Bryant wrote:The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.Here's how to put it in diagnostic mode:http://bryantrv.com/docs2/docs/singlezonediag.pdfGo to the ROOF AC control board. There are those 2 blue wires. When set to turn the furnace ON, BOTH those wires should have 12 volts. When the furnace is OFF, only 1 of those wires will have 12 volts. IF NONE have 12 volts, your furnace fuse is either blown or you have a wiring problem AT the furnace. Doug

MrWizard wrote:Is that the little 3" square 'single zone'Controls one heater one A/C unitMy uncle has that in his new class B, (traded off his Thor Serrano)Seems to be a troublesome design, and it has a slow responseTry changing mode to heat , run the temp up to something like 80 or 90(for testing)Then set to ON do not set to autoThen wait , could take two minutes or more to come onThere was another thread few days ago, somebody wanted to replace itOptions are limited , it's a proprietary digital systemI saw a schematic posted someplace of the control box wiringMaybe it was from ChrisNOT a troublesome design. The problem is simple. People NEVER read the operation instructions for this single zone tstat and when they have operation problems, they blame everyone but themselves. Doug

Chris Bryant wrote:Here's how to put it in diagnostic mode:http://bryantrv.com/docs2/docs/singlezonediag.pdfThank you for this ;)IIRC there is also a reset sequence to reboot or reset the thing.

Help with Dometic Digital Thermostat | Good Sam Community

time2roll
Nomad
Dec 01, 2016
Snowman9000 wrote:
It might not be troublesome, but I wish I could replace ours with something with a narrower "hysteresis". That is, a tighter temperature spread. We got spoiled by the $20 replacement Hunter t-stats in our past RVs.
There is a new replacement version. I should have mine shortly.
Will be interesting to see if the function is any better.

http://www.dometic.com/USA/New-Products/New-RV-Products/ct-thermostat/
Sorry dometic changed the link, can't immediately find it.
Snowman9000
Explorer
Dec 01, 2016
It might not be troublesome, but I wish I could replace ours with something with a narrower "hysteresis". That is, a tighter temperature spread. We got spoiled by the $20 replacement Hunter t-stats in our past RVs.
time2roll
Nomad
Dec 01, 2016
Chris Bryant wrote:
Here's how to put it in diagnostic mode:
http://bryantrv.com/docs2/docs/singlezonediag.pdf

Thank you for this ;)

IIRC there is also a reset sequence to reboot or reset the thing.
dougrainer
Nomad
Dec 01, 2016
MrWizard wrote:
Is that the little 3" square 'single zone'
Controls one heater one A/C unit

My uncle has that in his new class B, (traded off his Thor Serrano)
Seems to be a troublesome design, and it has a slow response

Try changing mode to heat , run the temp up to something like 80 or 90(for testing)
Then set to ON do not set to auto
Then wait , could take two minutes or more to come on

There was another thread few days ago, somebody wanted to replace it
Options are limited , it's a proprietary digital system
I saw a schematic posted someplace of the control box wiring
Maybe it was from Chris

NOT a troublesome design. The problem is simple. People NEVER read the operation instructions for this single zone tstat and when they have operation problems, they blame everyone but themselves. Doug
dougrainer
Nomad
Dec 01, 2016
Chris Bryant wrote:
The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.

Here's how to put it in diagnostic mode:
http://bryantrv.com/docs2/docs/singlezonediag.pdf

Go to the ROOF AC control board. There are those 2 blue wires. When set to turn the furnace ON, BOTH those wires should have 12 volts. When the furnace is OFF, only 1 of those wires will have 12 volts. IF NONE have 12 volts, your furnace fuse is either blown or you have a wiring problem AT the furnace. Doug
MrWizard
Moderator
Dec 01, 2016
Is that the little 3" square 'single zone'
Controls one heater one A/C unit

My uncle has that in his new class B, (traded off his Thor Serrano)
Seems to be a troublesome design, and it has a slow response

Try changing mode to heat , run the temp up to something like 80 or 90(for testing)
Then set to ON do not set to auto
Then wait , could take two minutes or more to come on

There was another thread few days ago, somebody wanted to replace it
Options are limited , it's a proprietary digital system
I saw a schematic posted someplace of the control box wiring
Maybe it was from Chris
Chris_Bryant
Explorer II
Dec 01, 2016
The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.

Here's how to put it in diagnostic mode:
http://bryantrv.com/docs2/docs/singlezonediag.pdf

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