I can't get the furnace going again - 1976 trilluim

[thimith]

Hey campers,

My 1976 Trillium came with an old furnace. I managed to run it before I left home, but I'm now in the Rockies and I can't get it going.
Propane is definitely getting to it. If I depress the pilot light button, it can hold a flame, but the pilot light won't stay on. It'll quickly die off, even if I wait 3 minutes before releasing the pilot button.

I simply would like the furnace to work, even if I have to start it up manually.
Turning the valve to ON and bringing a flame to it doesn't do anything. Is there a system preventing the furnace to start like that?

I'm a noob, I need guidance. I'm cooold. Thank God I have warm blankets!

Here is what it looks like
https://drive.google.com/file/d/1pW571WiGr6LF9zjrXpcyKCQ-yt4G-SEi/view?usp=drivesdk

[sharon_b]

I’m sorry you’re cold, I kno how miserable that is. It sounds like the Thermo couple is dirty or has gone bad. For safety reasons you can’t bypass it & shouldn’t try. Try to find a hvac guy that can help you. YouTube vids might help too. Good luck!

[Daryl and Wendy]

When the pilot lights but wouldn't stay lit; it's likely the thermocouple. It's the short pencil looking thing the pilot flame burns against. Chances are that it has failed and needs to be replaced.

They are commonly available. Although t's best to take the failed unit to correctly match the replacement.

The thermocouple is a safety device that ensures the pilot light is on to ignite the gas when the gas is 'turned on' by the thermostat.

[sharon_b]

sometimes taking the thermocouple out & giving it a gentle polish with 000 steel wool (plain, NO SOAP!) will buy you a little time. it will work again for a little while but you're on borrowed time. best be shopping for a replacement ASAP. its not a hard job, to replace or clean. go slow & be gentle. you don't want to damage the tip or kink the gasline.

[sharon_b]

one more thought - see if the thermocouple is in the pilot's flame. I wonder if bouncing around it's misaligned? the "heat" from the holding the pilot on it is what makes the switch work. if the flame isn't right on the thermocouple you can hold the button all day but it will never fire.

[Terry in Fowler]

As Sharon stated It is likely they thermocouple which is there thin almost match stick part that the pilot is heating there end of. The flame should be heating the last 3/8" to 1/2" of the thermocouple or it won't produce enough electricity. The same goes if it is heating to much. The thermocouple will have a very slight glow when just right, but it is sometimes hard to see. If it glows to brightly the end will burn out over time. The thermocouple generates enough electricity to power a small magnet that hold the pilot valve open when you remove your finger. The pilot can get partially clogged with dust and other small debris. Many times I have used a wrench to tap around the pilot assembly to knock the debris lose and then used a vacuum to remove it.
If you do replace the thermocouple and have the pilot adjusted correctly an it still won't stay lit you probably needs a new gas valve which is probably not available.
If your lucky a large appliance supply house may be able to cross reference one.
Be very careful with all of the tubes. They crimp, twist and cracked easily.

[Tom 72]

They are all correct, very likely. It is not a difficult DIY task if you are handy, see YouTube videos.

Remember, the thermocouple itself does not carry, nor can it leak gas. All it does is allow the valve to close if it does not sense heat from a flame, or vice versa.

That said, if you aren't comfortable, seek help.

[brendadave]

You have a different furnace than we do, but with mine I often have to try lighting 2 - 3 times, sometimes holding the pilot for a while, but it eventually goes. I have also had trouble at high elevation in Yellowstone NP lighting anything propane, but no issues to date in the Canadian Rockies.

[stevebaz]

You may have to clean your gas jet. If there is anything obstructing gas flow you wont create enough heat to work the Thermocouple. Should have the gas pressure too.

[Gary P.]

Hi
I have an old trillium as well with a "hot box" furnace and it is reliable but can be temperamental too.
First thing to know is that propane is not as clean as natural gas. Given that its a "dirty gas", residue can build in a certain location... in the actual gas valve, right beside the furnace, there is a small needle valve that has this little copper cap on it that lifts up when the gas is flowing to the pilot light and when it is not flowing or gets disrupted that little cap settles down and stops the gas the flow.
So take that apart and you will probably find that there is gritty material restricting that little cap from moving ... a little polishing and cleaning and wonder of wonders! - the pilot light stays on and before you know it you're in business and toasty warm B-)
A word of caution ... be careful as that little cap is small and can easily disappear

[Daryl and Wendy]

We haven't used our gas furnace in a very long time. We found the heater was too powerful for the volume of the small trailer.

As we camp in serviced sites anyway, for showers and bathrooms, we use a small electric radiant heater. We found that a smaller heater that was more on than off gave us a consistent warmth without the cycles of too hot then too cold. It might be my imagination, but the small electric heater also seemed to reduce the amount of condensation.

Question: anyone have any feedback on underfloor radiant heat pads? There are pre-made pads designed to go under desks and in bathrooms. Surely someone has placed a pad on the floor under the table (bed). On the fg floor and under laminate flooring or a rug. Does it work? Not very well? Better than expected??

[thimith]

The short version:
The furnace was dirty and the thermocouple was too short.
----

Thank you all for your suggestions, it made me understand what I was dealing with a lot better.
One of the forum members offered help on the phone, which was tremendously useful.
Since most of you suggested that the thermocouple was dirty or dusty, I tried to blow the dirt out through the lighter hole. I blew my lungs out, and noticed there was a lot of crap in the chamber. So I opened up the chamber removing the nuts and there was old rust, a dead wasp and crap I'd rather not inhale. I blew some more, got that crap all over my face...
It's all cleaned up, it would still not start.
I went to the dollar store and bought air in a can, cleaned up even more. Still nothing.

Now I noticed that I was getting a yellow flame at the base of the propane nozzle (next to the thermocouple). I was told yellow flame = dirty. I blew some air through the nozzle and more dirt came out.

Tried it again. It works.
Turns out the propane intake was just too dirty?

The next day, it stopped working... I could get a nice clean pilot light when depressing the pilot button but it wouldn't keep the pilot light on.
Turns out my thermocouple isn't long enough to sit in the pilot flame and therefore never gets hot enough. I tricked out by putting a lighter to the thermocouple...

Eventually I also used pliers to get the flame pointed to the thermocouple a bit better. Now the pilot flame has been on for 24h and I've been enjoying warmth in Banff where a snowstorm landed in us...

[gordon2]

Thanks for the reminder of the importance of routine maintenance.

[Nick J]

It's almost certainly your thermocouple - a simple device that prevents gas from flowing without a flame. If you can get an exact replacement you won't have to fiddle with the adaptors, buy 2 they are simple to change and you will be prepared.

Nick J