I'm not sure where to post this. We have a 1986 Elite park model trailer. The furnace quit at the tail end of last winter. It had to be replaced. We got an excellent deal on a brand new RV furnace, but it's 12v. Our trailer is wired for 120v, no batteries, no converters. This obviously posed a problem. I called around but nobody could help me. For lack off a better option, i hooked it up to a 12v atv battery, which in turn was hooked up to a battery maintainer. My theory was that when the furnace kicked on it would run on the battery, and when it kicked off, the maintainer would recharge it. it worked for one night, and now nothing. any ideas? was the battery not big enough and I've killed the battery, or was my theory unsound? any advice would be appreciated

A 12V furnace needs a lot of current to run the fan. You need one or perhaps two deep cycle RV batteries, around 100 amp hours each ( the ATV battery is probably around 20 amp hours) and a good 45 amp or so charger/converter to keep them charged. You've got around 20% of the DC power capability that you need. Now, temperature and how warm you like it will cause this to vary around a bit, but basically your idea is right, you are just under-sized to make it work.Brian

it seems to me that with 120 volts it would be simple /easy to convert/invert/whatever to power a 12 volt appliance. just an overgrown wall wart should do it.bumpy

Check the label on your furnace to see how much current it draws. Or ask the guy who installed it to find out. Multiply that number times 12 to find the power required. Motors require more current to start so be generous in your sizing requirements. Check out Harbor Freight.

My furnace pulls about 5 or 6 amps if I remember right. You current battery and charger are not nearly enough.I would just use a 12v power supply and forget the battery. Radio Shack has some. Astron is an excellent brand. I would look for something rated at least 8 or 10 amps as a guess. The best way to size it is either find the label on your furnace or measure the current draw with an amp meter.

I'm still trying to figure out what a 12VDC furnace is. Is this a furnace connected to PROPANE but has a 12VDC blower? This is how most RV Trailer Furnance's are setup.The 12VDC is only required to run the blower. If this is what you have then a simple 120VAC to DC Power supply from Radio Shack should operate your 12VDC blower just fine. As said above they only need 6-8AMPS DC current.Roy Ken

12v furnace install in a park model. (120v) need help

13 Replies

westend
Explorer
Dec 02, 2013
DPP120-12-1
This is a small supply that is rated to 10A DC output and adjustable for voltage. It is used,most commonly, for HVAC systems and hence, needs to be reliable.

The ripple and noise are so low with these Lambda supplies that they can be used for medical device or even audio power. I use a similar Lambda DIN mount supply and purchased it NIB from Ebay for around $30.
ray486290
Explorer
Dec 02, 2013
yes, it's a propane furnace.
B_O__Plenty
Explorer II
Dec 01, 2013
If it's strictly a 12 volt volt furnace and doesn't use propane...Forget about it. You would get more BTUs out of a light bulb..

B.O.
westend
Explorer
Dec 01, 2013
That Pyramid power supply may work for a while but is built for the car audio crowd. I would want a totally reliable power supply, something that I knew was reliable and I didn't have to worry about. I'd be searching for one over here at Lambda.
RoyB
Explorer II
Dec 01, 2013
RICK WRAY - Does your new furnace also connect to PROPANE gas... If it is truly a DC FURNACE only it will draw a bunch of DC Current... I would want to know that before purchasing a 120VAC Power Supply. How many DC Amps do you really need...

Roy Ken
ray486290
Explorer
Dec 01, 2013
perfect, that's what i wanted to do in the first place (power supply) but every hardware store i asked thought i was speaking Russian....haha. thank you everyone. i found a pyramid psv200 20 amp on Walmart's website. is 20amp too much?

thank you all for your responses.
handye9
Explorer II
Dec 01, 2013
Power supply is probably the answer. There are several listings on eBay. Here is one for 120VAC input to 12VDC 20A output.
powderman426
Explorer
Dec 01, 2013
Bumpyroad wrote:
it seems to me that with 120 volts it would be simple /easy to convert/invert/whatever to power a 12 volt appliance. just an overgrown wall wart should do it.
bumpy

X2 beside it being 12 volt, make sure it has a large enough amperage rating.
RoyB
Explorer II
Dec 01, 2013
I'm still trying to figure out what a 12VDC furnace is. Is this a furnace connected to PROPANE but has a 12VDC blower? This is how most RV Trailer Furnance's are setup.

The 12VDC is only required to run the blower. If this is what you have then a simple 120VAC to DC Power supply from Radio Shack should operate your 12VDC blower just fine. As said above they only need 6-8AMPS DC current.

Roy Ken
KD4UPL
Explorer II
Dec 01, 2013
My furnace pulls about 5 or 6 amps if I remember right. You current battery and charger are not nearly enough.
I would just use a 12v power supply and forget the battery. Radio Shack has some. Astron is an excellent brand. I would look for something rated at least 8 or 10 amps as a guess. The best way to size it is either find the label on your furnace or measure the current draw with an amp meter.