Powering a gas furnace with a gasoline generator.?

Question

I am considering purchasing a 1200 watt (max) 10A generator. They are reasonably priced right now. I would think that it should power my furnace in case of a power outage. My furnace is 6 years old. It is a mid-efficiency type with a 4 position blower fan. It is connected to an electronic programmable thermostat. It seems to me if I disconnect it from the house wiring and divert it to the generator, everything should work including the blower fan, gas valve and thermostat. I would think that 1000 watts continuous would be adequate. Do you agree? Is there anything else I should know?

Answer 1

While the manufacturers specs on the label is the best place to start, sometimes it is not perfectly accurate or complete. Best approach I've had is to use a clamp on current probe with average and peak readings. This will give you operating and startup current requirements for the furnace. From there you can decide whether the 1200 watt generator is adequate. My hot water baseboard oil furnace requires only 276 watts while operating and 780 watts startup.
Perhaps the easiest place to do your wiring is at the main electrical panel. Remove the furnace wiring from the panel and install a twistlock plug on the end. From the panel, install a new twistlock outlet powered from the original circuit breaker. Under normal operation the furnace will simply plug into the outlet. During an outage, disconnect the plug and connect it to an extension cord to the generator. This will leave the emergency cutoff switch active in case you need to turn the furnace off.
Never connect the generator to your house with a double male cord, and always use it outdoors where there is adequate ventilation. Read my home generator page for other ideas.
http://members.rennlist.org/warren/generator.html

Answer 2

Hi Karnak, A little foresight goes a long way. That is a very good idea. I've done similiar things for family members. I've found the easiest, cost effective way is to unhook the furnace and install a receptacle and then a cord and plug for the furnace. Then all you have to do in case of an outage is simply unplug the furnace from your receptacle and plug it into the generator.
My thoughts though, if you are going to go through the expense of buying a generator you might want to size it larger. If and when your power does go out you will probably want more than just heat. Just think, if you had to go a week or two. You'll want a refridgerator, hot showers, lights. The first generator I bought was a 4500 watt, it wasn't large enough. I've since bought a larger one (8500 watt). If I were your I would at least buy a 5500-6000 watt. Something fuel efficient and quiet (Honda). Good luck.

Answer 3

You really need to find and read the label. If there is not one single label that covers the whole heater, you will have to add up the info from the blower and control box.

Typically most common household heaters are protected by a 15 amp fuse or circuit breaker. 15A x 120V=1800 Watts. I bought a Coleman Powermate for this purpose. It's 1500 watts continuous, but can handle a starting surge of 1850 Watts. This lets me run some lights too.

I see you have your eyes set on a 1200 Watt max. Probably will handle 1000 Watts continuous? Again, check your labels, it may not be enough to start your system reliably. (Maybe that is why they are cheap?)

A larger generator will eat more gas, even if you aren't using all of its output. If you have an extended outage, you better have a LOT of gas on-hand. Because your local gas station may not have power either, or the roads may be closed. A smaller unit can even be used for work elsewhere, not just for emergencies.

Use Sta-Bil fuel stabilizer in the gas to help keep it fresh. Also haul it out quarterly and give it a 30 minute workout. The manufacturers recommend this, and you will be moving fresh gas through it periodically.

Answer 4

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RE:
Powering a gas furnace with a gasoline generator.?
I am considering purchasing a 1200 watt (max) 10A generator. They are reasonably priced right now. I would think that it should power my furnace in case of a power outage. My furnace is 6 years old. It is a mid-efficiency type with a 4 position blower fan. It is connected to an electronic...

Answer 5

Gas Furnace Wattage

Answer 6

If all you want to do is be able to get emergency heat during a short-term power outage, just buy a small gas powered generator and a couple of portable heaters for inside the house that can be connected to the generator by a power cord or two. While in use, keep the generator OUTSIDE!

Answer 7

Look for the MFG's spec. lable on furnace. It contains serial, modle numbers and specs. It will also show how many watts unit needs to operate. My guess would be 1500 watts as blower motors generally require that much on startup.

Answer 8

It can be effective