Dometic RM24-Burner lights but doesn't stay on. - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-24-2011, 12:32 PM   #1
Junior Member
 
Steven Potter's Avatar
 
Name: Steven
Trailer: 1975 13' Trillium / 2010 13' Scamp
Ontario
Posts: 7
Dometic RM24-Burner lights but doesn't stay on.

I've got a very nice 1975 Trillium 1300; bought it about 3 years ago. We ran the Dometic fridge on propane for 2 summers and it worked very well. But this year, after lighting the burner, it goes out immediately after releasing the blue plunger. Tried many times at different thermostat settings; sometimes holding the blue plunger depressed for up to a minute. The burner always lights right away and I can see a flickering yellow flame through the view port. But the flame always goes out as soon as the plunger is released.

I've taken precautions to level the trailer; wind doesn't seem to be the problem; ambient temperature is about 23 C.

Any help greatly appreciated.

I'm a licensed mechanic, so if you'd like to suggest some serious dismantling, and can provide the details of the method, I'd be happy to dig in.

Alternatively, if you can recommend a good repair shop in the Toronto area that might be good too.

Thanks very much.
__________________

__________________
Steven Potter is offline   Reply With Quote
Old 06-24-2011, 01:01 PM   #2
Senior Member
 
Name: None
Trailer: None
None
Posts: 2,728
It sounds like a thermocouple problem . Thermocouple may be bad,dirty or bad connection at valve body . Second option is that flame is not hitting thermocouple at the right spot or flame is hampered by dirt or insect webs. The pushbutton is usually a manual bypass of the pilot valve so you can get the pilot light lit and then once the pilot flame is sensed the pilot valve is held open electrically by the milivoltage generated by the pilot flame hitting the thermocouple .
__________________

__________________
steve dunham is online now   Reply With Quote
Old 06-24-2011, 01:12 PM   #3
Junior Member
 
Steven Potter's Avatar
 
Name: Steven
Trailer: 1975 13' Trillium / 2010 13' Scamp
Ontario
Posts: 7
Steve,
Thanks for your reply; sounds like an excellent diagnosis.
Is there a way to visually confirm the thermocouple is positioned correctly? I've removed a few sheet metal covers, but still not able to directly view the thermocouple.
__________________
Steven Potter is offline   Reply With Quote
Old 06-24-2011, 05:21 PM   #4
Senior Member
 
Trailer: 2009 Scamp 16 ft / 2003 Durango
Posts: 692
I would check the burner for obstructions like spider webs or wasp nest blocking the combustion air. ( the flame should be blue )
When you have a blue flame there should be a inner and a outer flame, the tip of the inner flame should be just touching the thermocouple.

Bill K


Quote:
Originally Posted by Steven Potter View Post
I've got a very nice 1975 Trillium 1300; bought it about 3 years ago. We ran the Dometic fridge on propane for 2 summers and it worked very well. But this year, after lighting the burner, it goes out immediately after releasing the blue plunger. Tried many times at different thermostat settings; sometimes holding the blue plunger depressed for up to a minute. The burner always lights right away and I can see a flickering yellow flame through the view port. But the flame always goes out as soon as the plunger is released.

I've taken precautions to level the trailer; wind doesn't seem to be the problem; ambient temperature is about 23 C.

Any help greatly appreciated.

I'm a licensed mechanic, so if you'd like to suggest some serious dismantling, and can provide the details of the method, I'd be happy to dig in.

Alternatively, if you can recommend a good repair shop in the Toronto area that might be good too.

Thanks very much.
__________________
Bill K is offline   Reply With Quote
Old 06-24-2011, 06:03 PM   #5
Senior Member
 
Name: Darwin
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,029
Send a message via Yahoo to Darwin Maring
Do what Bill K states and go get some Pipe Cleaners (The kind of pipe you smoke) they are a fuzzy stuff on a wire and run the cleaner through the tube the gas goes through to remove any obstruction. Then look at the PILOT light to make sure it is blue and on the thermocouple. There may B a metal thing on the end of the pilot that directs the flame to the thermocouple.
__________________
Darwin Maring is offline   Reply With Quote
Old 06-24-2011, 07:12 PM   #6
Junior Member
 
Steven Potter's Avatar
 
Name: Steven
Trailer: 1975 13' Trillium / 2010 13' Scamp
Ontario
Posts: 7
Thanks Bill and Darwin. Will do the pipe cleaner-clean out and post more details tomorrow.
__________________
Steven Potter is offline   Reply With Quote
Old 06-24-2011, 07:45 PM   #7
Senior Member
 
Alf S.'s Avatar
 
Name: Alfred
Trailer: 2014 Escape 5.0TA / 2010 Nissan Frontier
Ontario
Posts: 3,815
Registry
Send a message via Yahoo to Alf S.
Hi: Steven potter... If you need some tech. advice I can recommend our local RV appliance tech www.gammonsrv.com They can even rebuild an older unit to work like new!!!
Alf S. North shore of Lake Erie
__________________
Alf S. is offline   Reply With Quote
Old 06-24-2011, 09:06 PM   #8
Senior Member
 
Tim Wood's Avatar
 
Name: Tim
Trailer: Class B for now
NY
Posts: 747
If you happen to take apart the orifice, don't put anything through it just clean with alcohol . I just took mine apart , and the burner and cleaned them real good. Runs like a top now. Your problem does sound like the Thermocouple , but wouldn't hurt to clean the burner too.
__________________
Tim Wood is offline   Reply With Quote
Old 06-25-2011, 12:25 AM   #9
Senior Member
 
AndyGee's Avatar
 
Name: Andy
Trailer: 1979 Ventura 13'
Alberta
Posts: 133
I'd start by replacing the thermocouple. They're realatively cheap. Take your old one to any HVAC supplier they'll be able to match it up as they are pretty standard and only a few different sizes and lengths of capilary tubes. 99 % of the time a faulty thermocouple is the cause of your problem.
__________________
AndyGee is offline   Reply With Quote
Old 06-25-2011, 09:43 AM   #10
Senior Member
 
Name: Darwin
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,029
Send a message via Yahoo to Darwin Maring
There is a small critter, some kind of a noseeum, that gets in there around the pilot lite and weaves a cocoon. I had this problem for the first time in 1973 and still today.

I was told back then that if I left the pilot on all year, it would prevent that and I did that with that camper. It was a gravity furnace and a real pain to clean out.

With today's water heater I just clean it out at the beginning of the camping season each year because it has easy access.
__________________
Darwin Maring is offline   Reply With Quote
Old 06-25-2011, 02:27 PM   #11
Junior Member
 
Steven Potter's Avatar
 
Name: Steven
Trailer: 1975 13' Trillium / 2010 13' Scamp
Ontario
Posts: 7
Problem solved; fridge working fine now. Thank you to everyone who provided suggestions.

I found that the root cause of the problem was a tiny spider web blocking the burner outlet. It was a very small, thin web, but I guess it doesn't take much to block such low pressure.

The blockage at the burner outlet caused the gas to "back up" to the combustion air intake ports, and so when the burning gas exited from that point it burned yellow. Should be something to remember if anyone else is trying to diagnose this kind of problem; proper combustion, as Bill K mentioned is blue.

Trying to see the burner through the small port is very difficult. I found that if you remove the sparker unit (1 screw) from the right side you can use a dental mirror to get a much better look at the burner tube outlet. Mine has a fine wire mesh screen over the end of the tube and the spider must have assumed it was a perfect spot to weave a web!!
__________________
Steven Potter is offline   Reply With Quote
Old 06-25-2011, 04:01 PM   #12
Senior Member
 
Tim Wood's Avatar
 
Name: Tim
Trailer: Class B for now
NY
Posts: 747
After reading your original post again and I saw where you said it was a yellow flame. I thought the thermocouple just might not be your problem. Glad you got her going, sounds like your on your way to being a Tech (with the mirror and all). Nice when things just work out huh ?
__________________

__________________
Tim Wood is offline   Reply With Quote
Reply

Tags
lights


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
SMEV Dometic 2-burner stovetop Pam Garlow Problem Solving | Owners Helping Owners 3 04-24-2011 09:03 PM
Would you want a three burner stove? Raz General Chat 31 03-03-2011 07:48 PM
Running Lights Stay on When not Connected to Tow Vehicle ted saxton Problem Solving | Owners Helping Owners 4 06-07-2010 08:20 PM
LED lights in Original light sockets - tail lights Cam A Modifications, Alterations and Updates 75 02-15-2009 11:54 PM
Three way LP three burner/grill bonnie w Modifications, Alterations and Updates 2 07-02-2007 05:45 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:38 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.