Looking for those warm fuzzies

[krowsea]

Actually, the fuzzies I've got, it's the warmth I'm attempting to find.

It looks like my '75 Sovereign has a combination of OEM and aftermarket heater systems, and they don't appear to play well together. There is a Suburban wall thermostat over the curb side bed which controls a blower motor of some sort that blows air (room temperature) out of a small vent at the base of the kitchen cabinet, next to the door.

Bolted to that same cabinet, also next to the door, but precariously affixed to a piece of wood paneling, is a Therm'X 634 wall heater with some type of ceramic pad behind a wire mesh screen. The heater is bolted directly above the (heater?) vents, but doesn't appear to be connected or work with the thermostat.

The Therm'X heater doesn't appear to work correctly anyway, so I'm looking to replace it with something that I can control with the wall thermostat. Any suggestions? All the heaters I've found so far are either big boxes that need to fit under something or need hiding somewhere, or they're small free standing units you plug in somewhere.

Is there a replacement heater that would bolt in the same location as the small wall unit I have now and work with the wall thermostat, or is there a 'replaceable' heater unit buried somewhere in the bowels of my A/S that I have as yet not come across?

Thanks!
John-Boy

[71_safari]

Well, I know nothing about the aftermarket heater - it sounds like some sort of catalytic type, but you should have a Suburban furnace. In fact, you do, otherwise you wouldn't have an operable blower. Mine is under the sink cabinet. If it is not lit, it will still blow cold air I believe. Check it out and if necessary, get it repaired. They are fairly common so should be able to get it fixed easily. They work great when operating correctly.

[krowsea]

Thanks for the info. I've not found anything that was obviously a heater in all my puttering and cleaning inside the trailer, but it makes sense that where there's a blower, there should be a heater. I'll root around again under the sink, assuming that something down there should be a heater, and see what I find this time. I appreciate the advice.

John-Boy

[71_safari]

Look for the furnace exhaust flange on the outside of the trailer - it is a cast chrome grille, about 6" high and 3 " wide and with an inlet and outlet (and often soot marks around it). On the other side of this, inside, should be your furnace. Mine is a brown sheet metal box about 16" wide and 20" tall. It has a small 6" square door on the front with access to the pilot and also a gas line, with shutoff valve, running into the side of the unit. It is ducted to both the front and rear of the trailer and also warms the tanks and water lines.

When I first lit mine, after picking up the trailer in Wisconsin, it was c-c-c-cold! It took forever to purge the gas line with the little pilot button, and get the pilot lit, but it eventually did light and create heat. However, mine was sooted up and didn't run too well until I had someone at a repair facility clean it out. Also, check the screen on the outside flange to make sure that it isn't clogged up (mine was), which will cause the unit to starve for air and run rich (yellow flame). It should burn nice and blue. If you get it working but have any doubts, DO NOT go to sleep with it on, and get a CO detector in any case. Mine gave me a headache and then set off a CO detector, so I didn't use it anymore until I had it repaired. It now works perfectly and keeps me nice and warm here in the chilly northwest.

-john

-john

[krowsea]

Originally Posted by 71_safari

However, mine was sooted up and didn't run too well until I had someone at a repair facility clean it out.
-john

Thanks John,

Did you have to remove the unit for the repair, or did they do it while it was still in the trailer? What type of repair facility did the work, RV repair, some type of heating and A/C service, or other?

John-Boy

[71_safari]

No, I didn't have to remove it, because it just needed cleaning and they were able to do that without removal. But I can't say how because it is not recommended apparently, and I would have to kill you. I was travelling at the time through Montana. For most repairs it would need to come out but it is not too difficult. I believe there are some posts on it in the repair section of the forum.

Did you locate it?

[krowsea]

Originally Posted by 71_safari

Did you locate it?

I haven't as yet been able to go look. I hope to check it out later this week. If (when) I find it, I might hook things up and see what it does. I am curious why the PO bypassed it and hooked up the wall mount ceramic heater. If mine can't be fixed, I may need to start looking for a gently used unit somewhere, as it gets cold in them there hills.

John-Boy

[overlander64]

Greetings krowsea!

Originally Posted by krowsea

I haven't as yet been able to go look. I hope to check it out later this week. If (when) I find it, I might hook things up and see what it does. I am curious why the PO bypassed it and hooked up the wall mount ceramic heater. If mine can't be fixed, I may need to start looking for a gently used unit somewhere, as it gets cold in them there hills.

John-Boy

The existence of a catalytic heater doesn't necessarily mean that the unit's furnace is inoperable. A previous owner who dry-camped with any frequency may have installed the catalytic heater as they typically consume little or no 12-volt power (depends on the model and manufacturer) - - a big benefit when compared to the appetite of the blower motor on the furnace. If you decide to try the exisiting furnace (if you find that one is present, and the blower motor operation would suggest its presence as noted earlier) I would suggest checking your owners' manual for the lighting instructions - - if it is similar to my '78 Minuet, the lighting process in unlike the unit that was in previous Nomad - - basically set thermostat such that the blower runs and allow blower to run for five-minutes, then set thermostat back so that blower shuts down, then press reset button on furnace and hold while lighting pilot (the manual cautions that lighting the pilot may take a minute or more -- and it always does on my Minuet).

If you find that the furnace is missing from your coach, the new Suburban furnaces require minimal modification to the coach to fit. The advantage of a new furnace is that they are available with electronic ignition - - no pilot to light (I have one in my Overlander and wouldn't consider a new furnace that didn't have this feature). When the furnace in my Minuet needs replacement (it may be a replacement item just due to age as my confidence level in any furnace more than 20 years of age is quite limited) it will be with one of the Suburbans with the electronic iginition system.

Good luck with your investigation!

Kevin

[krowsea]

Hi Kevin,

Thanks for the update. With what I've heard so far, I'm pretty sure I'll find a heater buried inside the cabinet somewhere. After your comments about the new Suburbans though, I don't know if I want it to work. I'm kinda like'n that electronic ignition startup thingie! The only draw back is the $400 - $500 cost for a new unit. If I can get my original one working, I may cobble it through this winter and maybe replace it before the next.

John-Boy

[MarkE]

Just an aside: you mentioned your auxillary heater being precariously mounted to a piece of plywood. Check to see if there may be hinges on one edge of that plywood. Owners sometimes mount Cat. heaters on a board (or a piece of plywood) with one side hinged, so the heater can be swung on the hinges to 'aim' the heater toward different living areas of the trailer.
I have seen some intallations that look very substantual and professional, and I've also seen some that looked flimsey and an eyesore (possibly even dangerous).
Actually, a well placed and maintained Cat. heater is a good addition to an Airstream if you will be using it in outside temps of 40-65 degrees. It comes in handy, too, on chilly mornings to "take the chill out" before the daytime temps rise (without having to turn on the furnace.)

[krowsea]

Ohhhhhhhhhhhh....'that' furnace.

Sliding the tambour door back and peering into the darkness with my miniscule flashlight, what did I behold but a big grey metal box. The same metal box I had previously admired for it's ability to completely fill the cavernous space while giving no hints to it's origin or intended purpose.

Using my best archaeology skills, I probed the artifact, gently moving wires and hoses aside in order to discern the hieroglyphics inscribed on a small paper tag on the side. Putting my glasses on and peering intently, I could just make out the words Gen-u-wine Suburban Furnace. Yee-Doggies kids, I've found the motherlode.

Further investigation (and pushing the door further open) revealed a big 'ol bad reset button and a metal plate for pilot adjustment. Yeehaw, I got's me a furnace!!!!!

Not knowing how long it had been since the furnace was fired up, I used common sense precautions. Squatting behind a 4' wide section of 5" thick lead shielding, I peered through the leaded glass observation window. My hand quivering in it's thermaly insulated welders jacket and gloves, I tentatively aimed a lit match at the pilot opening. Pushing the button with my gloved hand, closing my eyes and shoving the match in, I was surprised not to hear a Whoom, or feel myself jetisoned through the opposite wall of my airstream. Taking that as a positive sign, I looked through the viewport. Holy Mother of Wally B., I got's me a flame!!!!!!!

My finger quivering, I slowly eased up on the reset button, and was rewarded by the continuation of that gorgeous blue glow. Taking my other gloved finger out of my ear, I didn't hear a single hiss, pop or any other sound of impending doom. Shoving the lead shield from me like last weeks Pez collection, I basked in my new found heat source. "Houston, we have a heater".

Boldly sliding the lever on my fabulous Suburban wall thermostat, I was delighted to hear the blower speed wind up, followed by a satisfying, if muted, whoosh of fire and heat. Success at last! Wanting to be cautious, I figured I would wait to run the furnace for an extended period until I plugged in a carbon monoxide detector, just in case. As it sits now though, I've gone from a precariously mounted and nonfunctioning catalytic heater screwed to the wall by the door, to a fabulous and functioning factory installed Suburban heater in the span of 5 minutes. Ain't life grand!!

Thanks to everyone for all their help and suggestions.
John-Boy

[71_safari]

Good for you! (and a great description of the experience!)

Enjoy!

-john

[krowsea]

Originally Posted by 71_safari

Good for you! (and a great description of the experience!)

Enjoy!

-john

Thanks John,

It was a memorable experience, and I wanted to 'share'.

John-Boy

[sailquik]

I'm living in a 31' Excella 500 and the pilot lever on my Therm'x Catalytic heater broke last spring.
It's a Therm'x Caravan MARK IIA Catalytic unit.
If you want to sell the entire unit, I'd probably buy it.
Maybe you've tried it by now and want to keep it, but if not, let me
know.
To use the main heater (on the thermostat) you need the AC converter on, and that little puppy really sucks the kilowatt hours.
I use the main heater when necessary, but find the Therm'x warms the front of my trailer just fine most of the winter.
Anyone know where to get parts for a 1975 Therm'x Catalytic heater?

[Inland RV Center, In]

Originally Posted by krowsea

Thanks John,

It was a memorable experience, and I wanted to 'share'.

John-Boy

There are some experiences that you may not want to share.

It is wise to remove the furnace every 5 or 6 years, to clean it internally as well as to check the gaskets.

The combustion chamber does inhale dirt etc, and even a cup full of dirt is more than enough to alter the performance of the furnace.

There are gaskets between the fan and combustion chamber. There is also a gasket between the burner log and the combustion chamber. That gasket in particular, depending on hours of use, fails after a period of time.

When the burner log gasket fails, carbon monoxide will enter the trailer.

It is best to not assume the condition of any furnace that has been in service for a while.

It is far better, to remove it and have it cleaned along with replacing the gaskets.

CAUTION Some dealers simply try to blow out the dirt with an air hose. It cannot and does not do the job, period.

The combustion chamber is "S" shaped. The burner log must be removed. Then the dirt and foreign materials can only be removed by tilting the furnace sideways a number of times, which moves the dirt through the "S" chambers, and finally out through the hole that held the burner log.

Always be safe with LPG appliances, especially in an RV. Strange things happen.

An LPG explosion can be deadly.

Andy