Lazy Daze Owners' Group

Furnace problem

December 30, 2012, 09:21:54 pm

Yahoo Message Number: 135917

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I turned up the thermostat on my furnace today (2012 MB) and nothing happened.  It was working fine yesterday.
 I tried the obvious things:  batteries were reading over 13 volts; checked the fuse (even swapped it with a known good fuse) - no luck.  The LD, furnace and thermostat manuals offered no additional suggestions.
 I call the mothership tomorrow, but in the meantime anyone have any ideas?

Thanks, 
Don

Re: Furnace problem

Reply #2 – December 30, 2012, 10:13:30 pm

Yahoo Message Number: 135919

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I turned up the thermostat on my furnace today (2012 MB) and nothing happened.  It was working fine yesterday. In the meantime anyone have any ideas? Don

I have had several problems with my thermostat. If you remove it and connect the 2 wires and it works, you found your problem. The Contact points on mine didn't make a connection and cleaning them solved my problem.

Lon

2003 MB in Lake County, CA

Re: Furnace problem

Reply #4 – January 01, 2013, 06:16:30 am

Yahoo Message Number: 135933

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Hello all.

O, I'm going to throw

Re: Furnace problem

Reply #6 – January 02, 2013, 01:57:57 pm

Yahoo Message Number: 135956

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That is a good idea, I have one

Re: Furnace problem

Reply #8 – January 04, 2013, 08:55:19 am

Yahoo Message Number: 135985

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Eric I don't have a specific recommendation as I have gotten all of them I have bought to work. The last one I bought was a return item on ebay that I got three for around 20 total. They were Honeywell brand but made different even though they all looked alike.  They all pretty much have to be compatible as it is almost a "Standard".  I seen a reference to doing it and found this article. I more or less followed it when I made the mod in the small class A that got wrecked in October 20011. Since then I have done it in a couple of trailers and a small class B.
http://home.roadrunner.com/~morodat/hunter_install.html

Another reference
 http://www.modmyrv.com/2012/01/03/mod-100-honeywell-digital-thermostat

Basically they use a processor controlled relay instead if the mechanical contacts.  The difference in the hysteresis zone was incredible, the swing between on and off going from 7 degrees to a couple of degrees. I used it for both the heat and cool on that unit but as I said you have to add a switch to get the low cool.

Garry

Re: Furnace problem

Reply #10 – January 05, 2013, 02:41:33 pm

Yahoo Message Number: 136005

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Most any cheap digital set back thermostat should work fine. Most it not all of these don't need any power they usually work on self contained AA cells. But in something as small as an RV its pretty easy to just turn the temp back at night or when you leave and back up when you want heat.. Set back seems like overkill.
 However if you want it just go buy the cheapest one you can find and it should be simple to install. Walmart  Lowes,  HD all should have a likely candidate and it should hook up pretty much like the hunter in the reference I sent earlier.
 They use a simple internal relay to close the contacts and call for heat.
And the micro-controller controls the relay with the firm ware determining how things work. To the out side of the thermostat it is simply two wires that are open or shorted.  Power to the old thermostat can just be insulated and not used. A little more complicated if you also control the AC but not much. To the world outside the thermostat there is no difference between the simple thermostat and a fully programmable one.
 This  is not totally true is some of the new home two and three stage heating systems and variable speed fans. But in all the simpler  systems I have ran into in RV's they are simple as can be.
 Here is another reference to the hunter and he refers to a programmable Lux that he says worked as well, but doesn't show details. Most say the digital conversion is the best mod they ever made..

Garry

Re: Furnace problem

Reply #12 – January 05, 2013, 06:56:56 pm

Yahoo Message Number: 136010

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Hi Larry,
 I just installed a Hunter 44155 digital programable thermostat ($25 at Walmart) in my SOB. It replaces an old mechanical two-wire unit. I'm testing it now, with the MH sitting in the driveway, 32F outside. I wanted a programmable one to turn on the heat in the morning, so I didn't have get out of warm bed to do it!
 Very easy to install, as it controls just the gas furnace, but it can also do A/C. It's powered by two AA batteries.

Eric Greenwell