ThermX 635 heater

[danjoe91]

I am trying to find out how safe these heaters are. I have never used this, because the pilot will not stay lit. I installed a new furnace in the trailer, which works well enough that this does not seem necessary. As this was an original option on my trailer, I want it to work, but should I repair it or replace it with something safer?

[Jammer]

Opinions vary. It's a catalytic heater, and I don't think any catalytic heater is safe for use in an RV.

[Chuck]

I have one--works fine. I don't believe it is any more dangerous than any other propane appliance. Even a brand-new furnace can malfunction, and leak CO, and therefore, a CO detector is a must.
Its been so long since I've used it, though, I don't recall exactly....but I don't think that the pilot is supposed to stay lit. There is a thermocouple, which keeps the gas valve open, but there is no real combustion going on with these things. just a small amount to launch the chemical reaction that occurs, and then the heat from that reaction warms the thermocouple, which keeps the gas flowing. The reaction is from propane +O2 passed through the catalyst, which yields heat +CO2 +H2O.
Since it consumes O2, you should leave a window or vent cracked.

You probably just need to replace the thermocouple.

[slowmover]

Originally Posted by Jammer

Opinions vary. It's a catalytic heater, and I don't think any catalytic heater is safe for use in an RV.

Curious. I have my reservations, but the ones with externally sourced air for combustion seems to cover that reservation. What else to note? Incomplete combustion? The cat pad does seem to be affected by dust over time.

[blkmagikca]

Catalytic heaters are radiant heaters - they only radiate heat away from the pad; thus they do not really heat the rest of the trailer. My AS came with one (Olympic), and after a few months of freezing my a$$ off when boondocking, I switched it out for a blue flame heater. The blue flame is a convection type of heater; it draws cold air through vents in the bottom and emits hot air from the vents at the top. This results in a flow of air that heat the whole trailer (but NOT anything behind cabinets - i.e., does not heat plumbing pipes and holding tanks). While they do come with O2 sensors, I always crack open a window as well as the vent on top of the stove and the vent in the shower stall.

[Chuck]

Originally Posted by blkmagikca

... I switched it out for a blue flame heater.

got a link for this?

[blkmagikca]

Originally Posted by Chuck

got a link for this?

Take your pick: http://www.amazon.com/s/ref=nb_sb_no...e+flame+heater

I bought a 10,000 btu Procom heater 3 years ago. It heats the entire 32-ft Excella.

[slowmover]

Originally Posted by slowmover

Curious. I have my reservations, but the ones with externally sourced air for combustion seems to cover that reservation. What else to note? Incomplete combustion? The cat pad does seem to be affected by dust over time.

The Platinum Cat Heater is the one of which I was thinking. Draws exterior air for combustion.

[Jammer]

I've written elsewhere on the hazards and on alternative heaters to consider. A search will bring up these posts.

The hazards with catalytic heaters are:
- gradually elevated co levels as the pad deteriorates with time and use
- elevated co levels in the event of various mechanical problems, such as partial blockage of the venturi
- oxygen depletion, a problem in its own right and also something that will lead to more co
- accumulation of other toxic products of combustion in the very small living space

There are many alternative heat sources for use while boondocking although they are generally more expensive and more difficult to install since they require outside air. Dickenson/Newport propane furnace, propex heater, etc.

[slowmover]

Thanks.

Have you looked at www.ventedcatheater.com?

Regular pad replacement seems reasonable.

[Jammer]

Availability seems to be an ongoing problem with the ventedcatheater folks.

It is unclear to me from their website whether their product has AGA/CGA approval. I wouldn't install it without one or the other. The approval means there have been independent third-party tests of things like clearance, failure modes, etc. I am skeptical because the design lacks outside air for combustion and with the extremely small fan it is unclear to me how there could be sufficient exhaust airflow under all conditions (e.g. heavy winds ).

There are better alternatives

[slowmover]

Thank you, Jammer. I had the impression you knew more than me. Bookmarked for that day.

[68 Overlander]

We used ours for years in our 76. Worked perfect and is next to the door where most of the cold comes in during the evening when you are opening the door letting the dog out, bringing in the BBQ stuff, getting a cold beer, etc. It's not a furnace, its to help the furnace. You can always turn it off before you go to bed. I'd use it.