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Battery back up for gas furnace?

Power out today. Got me wondering how to get gas furnace to work. Check ed caked manual doesn't seem to be a way to turn on without electric pilot. For the future wondering what option there are. Have battery back up for WiFi wondering if there is simething similar for furnace. Doesn't happen enough to have generator. Furnace is a lennox series pvsb-6d model gsb8-187s. Any information/advice appreciated.


  • Jamie Hall
    Jamie Hall Member Posts: 18,977
    Check the current draw on it

    then figure out how long you want the thing to run for.  This will give you a good idea as to how much battery you need.  Also whether you want the changeover to be automatic or manual.  There are a number of inverter systems out there of varying capacity which would work which will also charge your batteries.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,564
    when the power goes out

    the blower on your furnace will probably drain even a large battery pretty quickly, so I would say that a generator would be the only option.--NBC
  • hissyfit
    hissyfit Member Posts: 10
    Steam furnace

    No blower. Steam, one pipe system.
  • vaporvac
    vaporvac Member Posts: 1,520
    steam BOILER,,,

    Good clarification. I was wondering why you were posting about a furnace in the steam section. When I first started pottery, I used to call the kiln an oven. That always used to rile my teacher until I got it straight.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • Joe V_2
    Joe V_2 Member Posts: 234
    this comes up often

    and I read these treads whenever they pop up hoping to learn of a convincing way to do this but there are always special cases and caveats. Enough to make me wait and keep reading. I wonder why industry hasnt responded with a solution? Seems like a way to make some money. I imagine everyone who has ever purchased a Gorton or Hoffman vent would probably buy a backup system. I guess no commercial solution, outside a generator, is what makes me leary.
  • Jamie Hall
    Jamie Hall Member Posts: 18,977
    Actually, Joe,

    there are perfectly practical commercial solutions.  They are usually sold, though, as part of wind or solar power installations.  They consist of heavy duty inverters -- I've seen units in the 50 to 100 amp range! -- and related electronics to handle charging and discharging, as well as relay to handle switching to and from mains -- grid -- power.

    They are not cheap.

    plus, if you want to keep your equipment running for any significant length of time, you also need a pretty substantial battery bank backing the whole thing up.

    It all depends on just what you want to do, and how you want to go about doing it.

    Generally I think folks find that it is cheaper and easier to have a generator, if power outages are a concern.

    Of course, with a generator, there's always the problem of wiring it correctly.  I don't really want to know what fraction of homeowners' generators are wired improperly...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChicagoCooperator
    ChicagoCooperator Member Posts: 323
    I guess

    I guess you could stoke coal or something... I've heard that the old gravity furnaces work with only a batter thermostat as do some boilers. As long as the gas is flowing you'd be good. 
  • DRHolden
    DRHolden Member Posts: 1
    Use your car and an inverter

    I have a Prius (I know you either love these cars or you hate them). I happen to love them for this very reason. They work great as an emergency generator. I've done it. My whole neighborhood electricity was out, and I had friends over to watch football on TV. I had the furnace, fridge, internet/cable some lights and the TV all working off my Prius for days.

    I have a 1500W inverter I bought on Amazon connected to the small battery of the car. It gets charged by the big EV battery, which gets charged by the engine when needed. So, it draws current from the small battery, and when needed, the car automatically starts up and charges the battery, then shuts off again. It's quiet, and pollutes much less than a standard generator. I changed the wiring on my furnace so that instead of being hard-wired, it's a plug, so I can unplug it from the house power and plug it into the Prius power. The Prius power is NOT connected to the house electrical system in any way because that is very dangerous for many reasons. For more info just Google "Prius as a generator" and you'll find others who have done it and provide more info on how to do it.
  • Joe V_2
    Joe V_2 Member Posts: 234
    i love that idea!

    who woulda thought a Prius to be a survival tool?

    I have a rule of thumb: The solution has to be agreeable with my credit card and insurance company. Unless my life is in danger.

    my brother has a prius. i'll do the research for him. thanks!
  • David_50
    David_50 Member Posts: 6
    After Hurricane Sandy . . .

    I cut the boiler out of the (electrical) loop and ran the boiler off a 500 watt inverter.  Check what your current draw is- the gas valve will draw a watt or two, and in my case I took down the chimney and side vented it, and that was rated about 80 watts.  Add it up and make sure you have an inverter that is rated 50% more.  (If you have a transformer to take it to 24V doesn't matter to the power rating.  I can show you the algebra- but it all comes out the same figuring the watts.)

    I rigged a three way switch, with one pole to house current and one to a plug for the inverter.  Ground all the boxes together, all the commons together (don't miss the common and ground for the plug!)  Make sure you know what your hot is (reverse something and breakers will pop).

    The boiler was ok with square wave inverter power, but the water heater was not. 

    It took longer (half remembered aircraft mechanic instruction, so I took it slowly).  My wife insisted that an electrician friend look at it- he was fine.

  • PMJ
    PMJ Member Posts: 1,177
    When all else fails

    I do have a generator but could still have steam heat without any power. I still run a standing pilot and have a pipe leg to easily install around the gas valve with a lockable valve in it. Just open that valve and I have steam. Totally manual yes but that is my worst case solution.
    1926 1000EDR Mouat 2 pipe vapor system,1957 Bryant Boiler 463,000 BTU input, Natural vacuum operation with single solenoid vent, Custom PLC control