troubleshooting a/c and furnace ( neither work )

[jdp3891]

i currently have no a/c or heat the fan does kick on but only on high the low settings do not work. can someone help me out and give me some troubleshooting steps and possible repair insturtions.

Model-2007 Innsbruck 24RKL.

Furnace- suburban / SF25

A/C- DOMETIC / 57915.54

DUO-THERM DOMETIC THERMOSTAT

 

[proost]

Hi, can you add some more information such as how you're camping and outside temperatures. Also, is that thermostat the digital type with the five buttons or all analog? I'm assuming that AC has the heat kit installed?

It's odd that both the furnace and the AC are out but they share some common points. They both share the 12V thermostat but one is 110V (AC/Heat Pump) and the furnace is 12V. It's possible that your thermostat has hiccupped somehow. I had this happened once or twice before and ultimately, popped it off and unplugged it and then reconnected it.

Otherwise, you may need to check your 12V power supply. It may be enough to power your lights but not enough to power your furnace and/or perform full functions on your thermostat. I'm not an expert but happy to help troubleshoot based on personal experience.

Welcome to the board. You've found a great resource!

 

[jdp3891]

Hi, can you add some more information such as how you're camping and outside temperatures. Also, is that thermostat the digital type with the five buttons or all analog? I'm assuming that AC has the heat kit installed?

It's odd that both the furnace and the AC are out but they share some common points. They both share the 12V thermostat but one is 110V (AC/Heat Pump) and the furnace is 12V. It's possible that your thermostat has hiccupped somehow. I had this happened once or twice before and ultimately, popped it off and unplugged it and then reconnected it.

Otherwise, you may need to check your 12V power supply. It may be enough to power your lights but not enough to power your furnace and/or perform full functions on your thermostat. I'm not an expert but happy to help troubleshoot based on personal experience.

Welcome to the board. You've found a great resource!

I'm currently hooked up to shore power and the temperature outside has been in the 20s .

The thermostat is analog and no there's not a heat pump on my unit. My battery isn't the best but I'm getting 13.5v to every terminal on the thermostat board except for the cool terminal. I ran a jumper wire trying to see if it work kick on but I got nothing.


I'm thinking the thermostat is shot and needs to be replaced.

 

[jdp3891]

I'm currently hooked up to shore power and the temperature outside has been in the 20s .

The thermostat is analog and no there's not a heat pump on my unit. My battery isn't the best but I'm getting 13.5v to every terminal on the thermostat board except for the cool terminal. I ran a jumper wire trying to see if it work kick on but I got nothing.


I'm thinking the thermostat is shot and needs to be replaced.

I was thinking I mean

 

[proost]

It definitely sounds like it could be the thermostat especially with the very unique behavior that only the fan works on high on your AC. Also, you're getting 13.5V because you're plugged into shore power and your converter is supplying DC voltage to your rig while also charging the battery.

If you do opt to swap it out, go for an upgrade. We've had one of these in our coach for the past few years and it's a game changer for us in our 2007. Dometic Duotherm (Analog) Replacement. It gives you full control of your heating and cooling like we have at home. Love this thing.

 

[L Spillman]

I had the same problem on another coach of ours and it was the thermostat. On ours the AC fans ran all the time even if we were on heat. Talking with the factory team we found that we needed to set the fan control on AUTO not high or low. Fixed our problem

 

[TedMortl]

i currently have no a/c or heat the fan does kick on but only on high the low settings do not work. can someone help me out and give me some troubleshooting steps and possible repair insturtions.

Model-2007 Innsbruck 24RKL.

Furnace- suburban / SF25

A/C- DOMETIC / 57915.54

DUO-THERM DOMETIC THERMOSTAT

Hello,

RE: Trouble with a Suburban / SF25

Here is a link to the manual, it has a troubleshooting guide in the back that you might find helpful, see link below.

Manual for Suburban SF25 Furnace

I hope this helps

Thank You

Ted Mortl
Senior Systems Specialist
(262) 498-6354 Mobile Phone
IAS | Industrial Automation Services
Sales . Services . Upgrades

 

[TedMortl]

I was thinking I mean

Hello,

RE: Trouble with a Suburban / SF25

It sounds like you have a meter and know how to use it - that is AWESOME!

Here is the electrical drawing for your furnace, see image below...

Check the BLACK, (BK), wire coming out of the LIMIT SWITCH and the RED, (R), wire coming out of the SAIL SWITCH to the "grounding terminal", if tripped the LIMIT SWITCH usually requires a manual reset, the sail switch is checking for flow thru the heat exchanger. Low flow thru the heat exchanger will prevent a re-light.

Good Luck...

Thank You

Ted Mortl
Senior Systems Specialist
(262) 498-6354 Mobile Phone
IAS | Industrial Automation Services
Sales . Services . Upgrades

 

[jdp3891]

I had the same problem on another coach of ours and it was the thermostat. On ours the AC fans ran all the time even if we were on heat. Talking with the factory team we found that we needed to set the fan control on AUTO not high or low. Fixed our problem

Heck yeah I remember my first time using a thermostat. Got the belt when my daddy got home from work haha thems was the good ol days. I sure do miss that man and having his help on these things.