Auxiliary catalytic heater

bhsl8 · 10-23-2002, 06:40 AM

When I purchased my trailer it had a small flat Thermax 360 catalytic heater which was mounted on the panel just inside the door on the left as you enter the trailer. It is propane fueled but does not seem to work because the thermocouple has failed. I have tried in vain to find a replacement thermocouple but I am told that it is obsolete. It actually has metric threads. I would appreciate any direction on replacements for the entire unit or if anyone is familiar with this catalytic heater do they know where I might obtain a new thermocouple?
Brouck Sleight

smily · 10-23-2002, 06:53 AM

The europeans use fueled heat for almost everything, (rather than electricity). Maybe you can find a thermocouple from a heater supplier on line at some european site.

A thermocouple is a thermocouple. You just need the one with the metric threads.

If you have noticed that almost all thermocouples have a long tube that extend between the probe and the actuator, this facilitates the ability to use the thermocouple on many different types of devices.

I am no authorty on Heaters but I do know how a thermocouple works.

Smily

74Argosy24MH · 10-23-2002, 07:21 AM

If you can find a similar thermocouple with SAE thread (it would have to be a larger diameter) retap the mounting plate and you will be good forever.

John

bhsl8 · 10-23-2002, 08:42 AM

Gentleman, both of your suggestions are part of our current strategy. So far we have been unable to find anything remotely like the thermocouple( thread wise)that we have locally but have not tried the online route yet. We have found a thermocouple that looks to be almost exactly like the one we have for the "Mr. Heater" type products. However, it is SAE threaded. We have talked about retapping the mounting plate but I am unsure as to its metallurgical content. My son has been handling that end of it and I must relight his fire(a poor pun at best). If indeed I should fail with the above strategies does anyone have experience with similar heaters for use in relatively cold weather without taxing the battery for the furnace fan?
Brouck

74Argosy24MH · 10-23-2002, 08:55 AM

The furnace also heats the holding tanks, I would be careful in below freezing weather relying solely on another source of heat.

Put an SAE jam nut on the back of the thermocouple. If it is secure and grounded it will work.

John

smily · 10-23-2002, 10:05 AM

There you have it!

SAE Locknut on rear of thermocouple, simplistic and ingenious.

Now why didint I think of that/ Hmmmmmmmmm.........

smily

74Argosy24MH · 10-23-2002, 10:29 AM

I did it years ago on a house water heater, should have thought of it first time around. Pahaska's post yesterday about his window latch flashed (finally) through my mind this AM with all the talk about metric and SAE threads.

Now that my mind is starting to warm up, if we think to the other end of the thermocouple where it mounts to the valve and it is also metric (likely), all this is moot, on to the European or Canadian web sites.

John

bhsl8 · 10-23-2002, 11:51 AM

Does anybody have any Web addresses for suppliers of thermocouples preferably of the metric persuasion? I did have one local gas company check on this and they told me that the equipment is obsolete. It is conceivable that they just want to sell me a new heater. Short of buying a new one I still think we might try the retapping of the bracket that holds the thermocouple.
Brouck

davidz71 · 10-23-2002, 12:39 PM

Brouck,
I don't want to seem too ignorant here but exactly where on the Thermax heater is the thermocouple?

bhsl8 · 10-23-2002, 04:33 PM

Craig, it is in the bottom right hand corner of the heater just underneath the outside cover with the thermocouple portion almost embedded in the fibrous material that disseminates the heat.Why doest thou ask?
Brouck

davidz71 · 10-23-2002, 04:44 PM

The Thermax unit was taken off the wall of my '77 Excella 500 by the RV dealer who was cleaning the unit up in preparation for the ebay listing. When I picked the unit up, the thing was on the floor in the corner. The dealer said he did not know if it worked or not and the previous owner said he did not know why the dealer took it off. I re-mounted it and as I was tightening the connection, the small tube the other side of the brass propane connection broke off 1/4" to the fitting. It is just sitting in my garage doing nothing. If it is the same model or they use the same thermocouple, you can have it for the shipping charge.

bhsl8 · 10-23-2002, 06:35 PM

What a nice gesture. Thank you very much. I will get the particulars off the unit tomorrow and post the information. Such a simple fix would really be nice. Thank you again.
Brouck

uwe · 10-23-2002, 07:17 PM

Brouck,
This is in response to your earlier question on how well the catalytic heaters work. we use ours when it's chilly in the morning or while sitting in the front of the trailer etc.
the heater will not heat the air, only surfaces near it. So if you're sitting in it's range, then you will get nice and toasty warm. The person around the corner will not feel it at all. It does warm up our wooden floor, and radiate some warmth from it, but don't expect miracles. I believe it is very fuel efficient. Ours works very well for it's intended use, but again, it can not heat up the entire trailer, or protect your plumbing from freezing.
Good luck with your search for parts.

bhsl8 · 10-23-2002, 07:28 PM

Uwe thanks for the insight. My intent is not to heat the entire trailer but to, as you suggested, take the chill off things. I would not anticipate relying on it to keep my pipes from freezing. I do think however it might keep some of my companions from complaining. Since most of the camping that we have done historically and anticipate doing will be without shore power, I hate to continually run the battery down with the fan on the furnace. You may have seen another thread initiated yesterday concerning an onboard generator. That may help me alleviate this problem as well.
Brouck