Inoperable Big Horn Furnace

[secondwind57]

Hello everyone. My wife Jane and I; both in our 60's; purchased a 2016 Heartland Big Horn in October and set up in a small private campground in southwest North Carolina on the 4th of November, only for the furnace to stop operating two weeks later. I had gotten up early and after a few attempts to start it up and a couple loud snaps of static electricity between my finger and the thermostat, the thermostat just locked up. It has remained unprogrammable and the digital display, though blank remains lit. Thank goodness for the propane oven, the fireplace and electric heaters. I believe the furnace is a Suburban SF-42Q while I haven't located any model number directly on the digital display Dometic thermostat. I tried to call a local mobile RV repair a couple times along with an email to the web site with no response, though an employee from a local business warned me off these local units due to their knowledge of unsatisfied customers who paid out money yet still their problems remains inoperable. May I ask for suggestions?

 

[Bogie]

Electronic thermostats can be negatively impacted by a static discharge. In fact, a static discharge can easily exceed 5000 volts.

I would suggest power cycling the thermostat by removing the 12 volt fuse of the circuit it is connected to. When you re-apply the power, the thermostat may operate again. If if doesn't, you will probably need to replace it.

 

[secondwind57]

Electronic thermostats can be negatively impacted by a static discharge. In fact, a static discharge can easily exceed 5000 volts.

I would suggest power cycling the thermostat by removing the 12 volt fuse of the circuit it is connected to. When you re-apply the power, the thermostat may operate again. If if doesn't, you will probably need to replace it.

Thank you so much. I just now discovered your reply. May I ask where the fuse would be located as I am completely new to all this?

 

[secondwind57]

Thank you so much. I just now discovered your reply. May I ask where the fuse would be located as I am completely new to all this?

I suspect I located the correct; if not the only fuse box at the bottom of the Pantry.

 

[Bogie]

Thank you so much. I just now discovered your reply. May I ask where the fuse would be located as I am completely new to all this?

Sorry, I don't know which fuse. Do you have a battery cutoff switch? You could unplug the shore power and turn off the battery cutoff switch.
That should work.

If not, you can pull the 12 volt fuse. Look for one marked Furnace. Could also be one marked AC. But they are not always marked correctly. You may have to pull one at a time until you verify which one turns off the thermostat.

 

[secondwind57]

Electronic thermostats can be negatively impacted by a static discharge. In fact, a static discharge can easily exceed 5000 volts.

I would suggest power cycling the thermostat by removing the 12 volt fuse of the circuit it is connected to. When you re-apply the power, the thermostat may operate again. If if doesn't, you will probably need to replace it.

Interesting enough, I once again pulled the furnace fuse and nothing happened as the digital display remained on But then at your suggestion I removed the air conditioning fuse, and this time the digital display turned off, though when the fuse was put back in, the digital display turned back on but remained blank as it had been. there wouldn't be any sequence of combined buttons to press simultaneously or something such as this to reset it, would there?

 

[Bogie]

I presume it's a Dometic. You can check the tools section of the form for different thermostats.

Go to..... Tools >> Heating/Cooling >> Thermostats >> Dometic , for the various manuals.

You can also take a look at this trouble shooting guide I found on line.

https://www.mortonsonthemove.com/dometic-thermostat/#10-how-do-you-reset-your-dometic-thermostat

Hope that helps.

 

[secondwind57]

I presume it's a Dometic. You can check the tools section of the form for different thermostats.

Go to..... Tools >> Heating/Cooling >> Thermostats >> Dometic , for the various manuals.

You can also take a look at this trouble shooting guide I found on line.

https://www.mortonsonthemove.com/dometic-thermostat/#10-how-do-you-reset-your-dometic-thermostat

Hope that helps.

Thank you very much. I attempted a reset but to no avail. Nothing but a blank blue light comes on. I am feeling a bit ridiculous having not tried new fuses just to be sure, though the meter showed them good. I finally succumbed to ordering a new thermostat at the advice of the technician we discussed the events leading up to it failing. Hoping that gets things back up and running. Thank you Bogie for your help!!

 

[secondwind57]

I presume it's a Dometic. You can check the tools section of the form for different thermostats.

Go to..... Tools >> Heating/Cooling >> Thermostats >> Dometic , for the various manuals.

You can also take a look at this trouble shooting guide I found on line.

https://www.mortonsonthemove.com/dometic-thermostat/#10-how-do-you-reset-your-dometic-thermostat

Hope that helps.

May I ask if you'd be wary to plug in a new Dometic Thermostat that you ordered and once opened discovered they have different insignia? First my old one and the second the one I bought.

 

[Bogie]

Not if it's the same part number. If in doubt, you can contact Dometic and ask.
This is the numbrer I have for Dometic. 888-867-4188

 

[secondwind57]

Not if it's the same part number. If in doubt, you can contact Dometic and ask.
This is the numbrer I have for Dometic. 888-867-4188

 

[secondwind57]

I am way out of my league trying to sort this stuff out. For instance is it just smarter to put a new furnace in rather than pay a mobile to figure it out $130charge for the mobile visit, a $100 service charge and then a hundred and thirty hourly rate. I could have my friend help e get it out and take it to him, but it is a 2016 big horn with original SF Q42. Plus he is saying Dometic is saying the 3314082.000 is the replacement for the 3314080.000 but the 080 had four zones and this one showing but one. Think there are less programs too But of course there could be something causing these issues. I am sooo out of my league.

 

[Bogie]

As the heater and AC are integrated and there is a control board involved, removing the heater and hoping that's the problem seems a bit extreme to me.

Looking at the part numbers you supplied, I noticed that on Dometic web site, both part numbers yield the exact same document for operating instructions. But, both documents only have the 3314080.000 part number on them. Would seem to indicate a direct replacement, but you are wise to be sure before swapping.

Also found another page on Dometic web site for Product Support. You can email them, but it also has different toll free number from the one I posted above. I would call or email with and ask if the 3314082.000 is a direct (like for like) replacement. They should be able to tell you.

Her is a link to the page. https://www.dometic.com/en-us/support/product-support-form

Hope that helps.

 

[secondwind57]

I must ask myself did I typed out a reply and then forget to post it or is it simply not where I presume it ought to be...lol. Anyhow I am not finding a reply that thanked everyone for their assistance in helping me get the furnace operational, for as of the end of last week we figured out the new thermostat and the furnace is working. Again thank you everyone.