Furnace Won't Lite

[gypsmjim]

I'm guessing that this is a lost cause, but I'm going to give you guys a shot at it anyway. First of all let me say that the furnace in question is an antique....

Our old trailer being used by our kids has a Unitrol DuoTherm gravity furnace. It has always been a champ until now. The pilot will light no problem, but it won't stay lit. New thermocouple, right? Replaced it but still no luck. I thought maybe the pilot wasn't getting the TC hot enough so I heated it with a propane torch and still no go.

So could the gas valve be bad? Not accepting the mv signal from the TC.

I contacted 2 local old time dealers and this type of valve hasn't been available for years and years. Everything today requires 12V, but our trailer has no electrical system - its fully propane self contained.

I'm considering buying a similar size catalytic heater, but I thought I would survey the group first.

TIA for any help...

[us71na]

Beware of catalytic heaters in a closed camper. They make pretty high amounts of CO (carbon Monoxide) which is deadly. They also release CO2 (carbon dioxide) directly into the air you are trying to breathe which can also prove to be deadly. They also deplete the Oxygen levels in a closed room to hazardous levels. Take a look at this study. CO EMISSIONS FROM A PORTABLE PROPANE CATALYTIC HEATER Pay close attention to the conclusions on the bottom of page one and top of page two.

It might be time to invest in a new heater. I think you got your moneys worth out of the original.

[JEFF1963]

I'm not suggesting you use the heater until it's diagnosed and running properly, but I also distrusted catalytic heaters - to the point of paranoia. However, I had several firemen in my unit and asked them their thoughts on cat heaters. They had the same thoughts us71na had, they can be extremely dangerous, BUT - with adequate "make up air" (that is an open window or 2), they're perfectly safe. They really aren't very efficient without a fan to distribute the heat, but they'll do in a pinch especially if the camper has no electrics. I, however, wouldn't buy a new one. Just pile on the sweaters, blankets or get a good sleeping bag.

[Higgy]

sounds to me like the gas valve as you have changed the thermocouple. I have seen thermocouples that were broken from new, though not very often. Apart from stripping the gas valve and cleaning/checking it then replacement is the next step but if you cant find one...

Found this on another site. Not sure if its helpful.
http://www.ntpdistribution.com/PDF/V...kchart1of2.pdf

[gypsmjim]

Originally Posted by Higgy

sounds to me like the gas valve as you have changed the thermocouple. I have seen thermocouples that were broken from new, though not very often. Apart from stripping the gas valve and cleaning/checking it then replacement is the next step but if you cant find one...

Found this on another site. Not sure if its helpful.
http://www.ntpdistribution.com/PDF/V...kchart1of2.pdf

Thanks so much. That was REALLY helpful. I couldn't find the right part no matter how far I searched. That led me to the right one.

But....

I called them and they wouldn't sell me what i needed - they were wholesale only. They referred me to a local dealer, who just happens to be a crook.....LOL. I went in to see what he could do and he wasn't even interested - until I gave him an actual part number (from your link above). He was willing to order it, but it came to $455.00. Holy crap!. That's about double what the trailer is worth! I can buy a brand new complete modern furnace for less money. And of course the catalytic heater is cheaper.

Not sure what we're going to do yet. Sweaters and a sleeping bag are not the answer. At times we hunt in single digit temps. Sleeping is fine, but eating in 10 F temps is not conducive to good digestion. Maybe the kids and all will have to stay in the new Jayco...

[gypsmjim]

UPDATE FOR THOSE THAT ARE INTERESTED:

Fixing the old furnace was cost prohibitive, plus the only local RV dealer that would order the parts is a *&^%$, and I won't deal with him.

We ended up buying a Camco Wave 8 catalytic heater. I DID listen to the comments here, but also did enough research to feel OK with it.

The install went very well. We put it in the same space as the old unit. A few modifications (cutting wood panels) was needed, but not a big deal.

Spent the first night in 35 deg. temps and the heater performed very well. We cracked opened 2 windows (as recommended) and our CO detector showed zero problems.

Considering it is actually gravity heat (no fan), the uniformity in the trailer was outstanding. The floor to ceiling gradient was much less than the old flame fired furnace.

The old trailer turned 52 this year - I guess she'll live for a few more years.

Thanks to all for the help...

[JEFF1963]

Dontcha love it when a plan comes together (sorta)? Happy to hear no frostbite occurred that night. I would still reiterate my recommendation for a small (portable AA fan?) fan to distribute the heat around; what could it hurt? Maybe place it where no one's going to stomp it. It might allow you to use less propane.

[gypsmjim]

Originally Posted by JEFF1963

Dontcha love it when a plan comes together (sorta)? Happy to hear no frostbite occurred that night. I would still reiterate my recommendation for a small (portable AA fan?) fan to distribute the heat around; what could it hurt? Maybe place it where no one's going to stomp it. It might allow you to use less propane.

I already have a small 12V fan. It was an old auto fan that was used in the rear window to keep it clear (that goes to show how old it is.....LOL). It is still in our 3rd trailer on site - the one with the still operating gravity furnace. I used it exactly once. It was noisy and didn't help much. I was so impressed with the uniformity of the new heater that I don't thin k we need a fan anyway.