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Thermostat Furnace Motor Bushing - Burnout Fiasco


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Well, this isn't my first experience in the 'Rader with Murphy's Law, but I believe if it saves someone else $80 -$150 weasel-hides, it's worth sharing..... Here's what happened: In the course of my rebuild, I purchased a used-good condition Hydro flame furnace from the good RV Doctor George, here in Sacramento Ca. (Passed last July, bless his heart).

When I got around to installing it, I used the original '85 thermostat (also Hydro flame) from the rig. It seemed in good condition and a new one was about $30, so I cleaned it up and installed it. Wish I had a picture of the old unit, but it was hauled away in the trash this morning. Here's why: the stat's lowest temp setting on the sweep-arm was labeled 50 degrees. Fair enough. There was a small amount of additional adjustment to the left of that (in the direction of declining temp). I "figured", (ho-ho-ho,figured, that's rich), like most stats that I have ever used, that this was the "Off" position !! Nope. As a result, after installing it and testing it, and after I left, every time the temp went below 50, the thermostat turned on the fan and attempted to initiate the lighting cycle. With the LPG turned off, the fan just kept running until the exterior temp went above 50 and warmed up the coach. This, of course, eventually dried out the fan bearing/bushing from overuse. The motor now has the familiar "irritating-squeal-of-death" and (even if lubed) now needs a rebuild or replacement. So,.. I got that new thermostat (WITH an On/Off switch!) and looking for a place to replace the bushing, or I'll buy a new motor. When that is done, next winter I'll be able to just turn off the LPG and set the new stat to Off instead of pulling the fuse to the furnace. Puzzling why the old unit was designed that way, but mine is not to reason why, ... just get out the check book and wrenches. Truth here is, I guess I could have tested the old stat with some canned Freon to below 50Deg, with the unit turned all the way down, but now I can be in the Murphy's Hall O' Fame.

Cheers,

TG

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every time the temp went below 50, the thermostat turned on the fan and attempted to initiate the lighting cycle. With the LPG turned off, the fan just kept running until the exterior temp went above 50 and warmed up the coach. This, of course, eventually dried out the fan bearing/bushing from overuse.

The newer replacement control boards for the furnaces have "fan off" feature. So in your situation - with the newer board, the fan would of shut off and stayed off - regardless if the thermostat was calling for heat or not.

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Weird, my Sunrader is only a year newer and mine thermostat has an on off button in the front

Here's a thread on how John repaired his furnace

http://toyotamotorhome.org/forums/index.php?showtopic=3520

and here are furnace motors on ebay. One must fit

http://www.ebay.com/sch/i.html?_odkw=&amp%3B_qfkw=1&amp%3B_mqf=0&amp%3B_trksid=p2059388.m2835&_osacat=50067&_from=R40&_trksid=m570.l1313&_nkw=furnace+motor&_sacat=50067

This one is the part listed in my 8500 series Hydroflame manual. I don't know what furnace you got from Dr George though

http://www.ebay.com/itm/Hydroflame-Furnace-Motor-8525-31-part-37697-G-/140907471665?pt=Motors_RV_Trailer_Camper_Parts_Accessories&hash=item20cebd6331&vxp=mtr

Linda

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A modern thermostat has an off setting there is nothing special about the thermostat a big box will have any type you like. I use a computer type one in mine with built in timers for different temp settings.

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my vintage oem big old hydroflame thermostat has an on off switch . Left it all the way down once and forgot to turn the off lever to off and went out to it and found to my surprise that the rv battery was totally dead. Did one other good bo bo went up in the woods after a couple of trips and didn't think about checking the propane. midnite ran out of propane no heat for wife and fridge out but saved stole bbq tank off my sons grill right under his dogs nose he slept on.

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