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starting up gas boiler with portable generator or battery?

jim_14 Member Posts: 268
When the recent storm hit ,I lost power for 2 days after being told it would be 7. Luckily we only had to deal with 2 nights of no power, and our gas fired hot water tank provided us with hot water for our showers.

But I realized that if the weather was colder we would have no way to run our 1 pipe gas steam boiler w/hot water tapped off for our basement.

So , my questions:

Im planning on buying a portable generator to run the refridgerator and a lamp or 2 in case we ever lose power for an extended period of time. I also would plan on being able to "start" and run my boiler for an hour here or an hour there to provide heat to my home. Its a rather small system, 105,000 BTU's for approx 290 sq ft of steam generation.

Can you guys who are experts give me an idea of watt wattage/amperage I would need to provide the power to run my boiler in case of an extended power outtage in the dead of winter? (Yes I am familiar with basic electricity and wiring and I am capable of opening the circuit and isolating the boiler from the emergency cut off switch and placing it back when power is restored- there would be NO back feeding of electric into to the panel!!)

Or is there a "battery" way of getting the boiler to run long enough to make heat for maybe 30 to 45 minutes assuming from a cold start? I know I could get a UPS but I dont know if that would last for a few days or up to a week if needed.

My goal here is to avoid a no heat situatution in the worst possible case in the winter months. I could live without lights and refridgeration and not having to store gasoline for a generator if a batter option was viable

thanks in advance for you help!


  • SWEI
    SWEI Member Posts: 7,356
    measure first

    You need a clamp-on ammeter with a peak hold feature so you can determine your real requirements.
  • BobC
    BobC Member Posts: 5,471
    A generator

    My old Burnham oil fired steam boiler pulled about 5a off the line so that works out to 6-700 watts before we start to think about power factor, batteries just wont last for oil fired boilers.

    Batteries feeding inverters on traditional gas fired steam boilers will work especially if you can manually operate the auto vent damper. The inverters are not very efficient at low loads so you need a way to recharge the batteries if you have to run the boiler for a number of days. You might be able to use the car to charge them but it will take some finagling to do it right.

    You really should measure the current draw on your system and remember newer systems need reasonable power so you need a good clean generator and they are not cheap.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
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