Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > MOC Technical Forums > Repairs & Service
Click Here to Login

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-21-2024, 09:36 AM   #1
ThisIsMyUserName
New Member
 
Join Date: Jan 2024
Location: Felton
Posts: 1
M.O.C. #33867
Dometic furnance DEMD30111

I installed this furnace in an older RV 12 months ago as the original Atwood furnace is no longer in production. This was dometics direct replacement.

The furnace ran great up until a few days ago, and it was only used during the very short Cali winter.

What itís doing,
Starting up, fan working, it fires, and stays lit from anywhere from 1 second to several minutes doing this several times over. It eventually turns off and then repeats this process. It is giving no indication of fault via the circuit boards lights so Iíve been left to my own devices as to figuring this out.

What Iíve done/checked
-vents are not restricted and have good air flow
-I replaced the regulator even though I didnít think that was the problem as all other appliances worked great. Strong blue flames.
-The propane tanks are full and new. And Iíve tried several.
-the sail switch was a little dusty, it got cleaned and I tested continuity.
-the burner was cleaned with a torch and a wire brush
- the spacing on the igniter is still at factory spacing and I do not know specifically what it is. I did take it off when cleaning the burner, was very careful with it so as not to bend it, and put it back on.
-power is good on batteries.

TheRV hasnít moved in 3 years and has been parked in the same spot under a tent carport with sides and 5 foot clearance from wall. I believe the potential for moisture to have damaged circuit board to be very unlikely but always possible.

Any ideas?

Thank you,

-Cold Electrician
 
ThisIsMyUserName is offline   Reply With Quote
Old 01-21-2024, 12:07 PM   #2
jimcol
Montana Master
 
jimcol's Avatar
 
Join Date: Dec 2007
Location: Kansas City, Missouri
Posts: 2,700
M.O.C. #7992
Send a message via AIM to jimcol Send a message via MSN to jimcol
Some have reported that the black resetting fuse in the DC distribution panel have caused intermittent problems. If you have such a beast might replace it with a regular blue fuse.
__________________
2006 3000RK
2009 Ram 2500
jimcol is offline   Reply With Quote
Old 01-21-2024, 01:36 PM   #3
Daryles
Montana Master
 
Daryles's Avatar
 
Join Date: May 2019
Location: Alton
Posts: 2,613
M.O.C. #24086
The 2019 models had a bad batch of circuit boards. One of our members proved it by putting it in the freezer for a few hours, then testing it. It would not run. I don't recall the exact symptoms it exhibited.
He then put a hair dryer blowing on the circuit board to warm it up and it started working normally.
We had the symptoms you are currently experiencing while in Yellowstone Fishing Bridge (elevation 7,800'), it was very cold and that propane tank was low. When its first turned on, it would short cycle and turn off. I had to pull the fuse to restart the furnace (same thing as pushing the reset button on the outside). After many short cycles, the on cycle got longer and longer until it ran normally.
I'm guessing it warmed up enough to run.
The local RV Tech (yes they actually had an RV Repair station there at Fishing Bridge Yellowstone) I spoke to said that morning he had three other RVs doing the exact same thing. He believed it was a combination of low propane, very low temperatures and high elevation.
After we left Yellowstone the furnace worked fine (lower elevation, warmer weather and full propane tanks).
Just last week we had the same thing happen here at home. Outside temperatures at 0⁰F. It has not been above freezing in two weeks. The furnace would short cycle. I put heaters in the basement to warm up the air down there. The furnace has worked fine since then.
__________________
Daryl and Marianne,
2019 3130re 20th Anniversary Edition
2016 F350 Lariat
Daryles is offline   Reply With Quote
Old 02-02-2024, 05:55 PM   #4
mpkahl@att.net
New Member
 
Join Date: Jul 2023
Location: AZLE
Posts: 1
M.O.C. #33046
I had the same issue and just replaced the main board bought through amazon for $58. Lesson learned is if you have the face of it off and the vent tube removed it will not light and stay lit until you put the vent to back in with the cover off while you are touble shooting it Very important to have the vent tube in or it will light then go off and try it for 3 times and shut off.
mpkahl@att.net is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 10:52 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.