Can I use an EZ Generator Switch as a transfer switch with a Generac GB1000 battery and a gas furnace (Bryant 340aav). If so, should it be setup as bonded neutral or floating neutral (I'm guessing it's supposed to be floating neutral). If not, is there a transfer switch that would work? (maybe Reliance Controls?)

  • 1
    FYI you're not going to get much run time with a 1000Wh battery. Depending on the specific furnace model you have, the blower fan alone takes 500-1000W. So maybe one or two hours of total runtime, if you're lucky (likely less, because the fan isn't the only load). s3.amazonaws.com/s3.supplyhouse.com/product_files/…
    – nobody
    Mar 23 at 1:31

1 Answer 1


Yes, the EZ Generator Switch is perfectly usable and uniquely suited for furnaces - pretty much the "killer app" for that particular product.

Your furnace will already have a steel Handy-Box containing a switch and/or fuse. You simply replace the Handy-Box with - well, follow the instructions.

The only thing I don't like is the need to leave door cracked open for the extension cord, since carbon monox.... battery, duh, nevermind!

Honestly, I'm not sure the battery is going to work for you. These "solar generators" or "portable power stations" or whatever they call them these days, are biblically overpriced for what you get. You can tell they're scammy because you have to dig deep in the specs for The Single Most Important Parameter for these units that should be right up front. But they really, really do not want you to be a competent shopper, because if you were, you probably wouldn't buy one. At least not theirs lol.

As it happens the "1000" unit is 1000 Watt-Hours, and the "2000" unit is 2000 watt-hours. (Well OK it's in the model number, but you can't take that for granted, ever!) 1000 watt-hours is about the storage you can expect from a $150 car battery (better: deep cycle marine starting battery) from CostCo. And so you can rely on data from people who have tried running their furnace off a car battery, like this guy.

I don't agree with the hatchet job the guy did wiring up the furnace - it doesn't switch neutral like it needs to, and I don't see a fuse.

That video's report of 6 hours feels about right to me. Furnaces take a lot of power. Once you install the switch, switch it to generator and feed your furnace through an extension cord via a wall outlet and a Kill-A-Watt. It will read out the watts it is using.

Mind you, this only works because it's a gas furnace, and it's only using electricity to push the fluid around (e.g. air, or water in a hydronic system). A furnace that uses electricity as the literal heat source simply will not work on battery.

The cost of lithium batteries has dropped like a stone in the last 10 years, to 15 cents a watt-hour. The "power stations" haven't dropped a nickel and are still at $1 a watt-hour. I do not like them, I think they are insanely oversold to 1%ers and dumb people, and 99% of buyers think they will do more than they will do, because they don't understand amps and watts and watt-hours.

  • "A furnace that uses electricity as the literal heat source simply will not work on battery" - is that a challenge? how many LiFePO4s do you think I'd be able to pile up before the floor would cave in?
    – user253751
    Mar 23 at 10:53
  • @user253751 or until the batteries themselves combust and become the heat source...
    – FreeMan
    Mar 23 at 12:49
  • 1
    Spot on about value for money. $1000 to keep your furnace running a few hours if you have a gas water or steam system, or maybe an hour if you have forced air. For that period of time I have a much better system, it's called a "jacket".
    – jay613
    Mar 23 at 14:02
  • Yeah, I'm a huge fan of battery/electric, but forced air furnaces are just too power-hungry. We have a Williams/Montery 50k BTU wall furnace that requires no electricity, and I don't understand why it isn't a standard feature in every snow belt home with gas. Use it as emergency heat, with a modern heat pump or a condensing gas furnace as primary. Needing electricity for heat - what a dumb idea. Forced-air only exists because it enables 1959-era A/C systems. Today, we have mini-splits. Mar 23 at 20:13
  • @user253751 at that point you'd just buy a wrecked Nissan Leaf at an auction, and take the battery and battery charger out of it. Now for a couple grand you have a 16-40 kWH battery pack and fast charger. Now you need an inverter and some bits, but you can see why I think those $1000 Jackery's are good money after bad. . You need some more bits, but you can see why I consider Jackerys to be "good money thrown after bad". Mar 23 at 20:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.