I was hoping you'd have the asterisk footnote on the items with a motor, particularly those for compressors - the surge watts requirement is higher than running watts for them. You can't run them if you don't have enough electromagnetic torque (surge watts) to start them....

So, I could use a little education here concerning the 2 leg 120v requirement. If my furnace is connected to a single 14/2 or 12/2 wire wouldn't that be to just one leg of the breaker box?

The hair dryer my wife uses is 1800w.

Generally yes, your furnace blower motor is 110V motor with that size wiring. If your furnace uses natural gas or propane as it's heat generating source instead of resistance electric heat strips then the furnace only needs the 110V motor to move air through your duct system. I've never seen a gas fired heater with a 220V blower motor. Conversely if you have electric heat then your motor is almost assuredly a 220V motor.

Most heat pumps have a back-up electric heat strip system thus 220V to the blower cabinet.

You ever sneak it from her for heat shrink and terminal connectors?

I wired up my elderly neighbor's gas furnace to a plug so he could run it from a generator last week. It was a 120v blower and he ran it on a Honda ex800 generator. I was wondering if the generator had GFI outlets, I know a motor with caps will trip those.

It is a 120V 2 stage heat gas furnace.

The blower motor will run but the board locks out ignition saying "Incorrect Polarity or Bad Ground".

I switched the polarity and hooked the ground up through a piece of 10 Ga. solid copper in case the stranded wire wasn't making enough connection.

It is a new 80% 2 stage gas furnace with an ECM motor in it.

The blower motor would come on and blow constantly but the board would blink 9 times giving the "Incorrect Polarity or Bad Ground" code.

Back-up heat strips seem to run from 5kwh to 25 kwh. Not hard to determine what caused the demand spike when the temp was really low last week. That's like having 2-3 electric dryers running 24 hours/day.

It seems to be a common problem with multiple brands and some of them have even said they wouldn't run on whole house generators.

One of the Generac guys here said he has been installing an aftermarket board in his to trick the Rheem furnaces into running.

I have not tried anything else or spoken to anyone at the manufacturer about it yet.

A buddy of mine tried running his older one on his 9000W generator and it would not fire either after trying everything he could think of.

Have you took a meter and checked how much voltage your generator is putting out? Some are adjustable and it may only be doing like 90 or 100 volts, it will run but the computer boards not getting enough juice so it thinks it has a bad ground.

I’ve had one since I moved to Rayburn in 2016. It hasn’t missed a beat in 5 years. I have a maintenance contract on it and it has a sensing device on it that reports generator status back to the installer’s office. They perform regular maintenance. I have an 1800 square foot house with a total electric house and an aerobic septic system,. It’s a 22KW and if it’s Junk, then I guess others must make your coffee for you. That said, there are other brands out there if you think Generac is junk. The CEO of Generac recently reported a 6 month waiting list if you want one, or you can get up in zero degree weather pull you “maybe it will do the job” generator out, run extension cords, and hook up a space heater or two, then hope the pull start actually starts it. In the meantime, my Generac will be supplying power within 20 seconds of the power going out. I love it when someone “heard” something about some consumer product, but badmouths someone’s purchase.

Nope...have a Makita.

https://www.amazon.com/gp/product/B079M8YVM4/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

Nice!!