A battery backup for the starting mechanism is probably possible, but the bigger problem is the power to drive the blower. That requires the majority of the electrical power required to run a gas furnace. Sump pumps runs in bursts, so it doesn't require continuous power. Cable telephones are low voltage electronic devices, so it doesn't require a lot of power either. That blower in the furnace though will probably require more power than your typical battery can run for any decent length of time. A better bet is a small generator when your power goes out. That's what I do. A small 2000 watt generator is more than enough to start it and run the blower (along with the fridge too!).

Although I don't have another suggestion for the furnace, can you advise which battery backup solution you have for your sump pumps? With this last storm we were flodded because we had no power. I am not looking for a genrator solution.

Thanks

There are battery back up sump pump units like the basement watchdog available at any home depot, lowes or other large home improvement place. There are also water type that us residential water pressure to run a pump that unless the city runs out of water, your basement will be dry.

About the only good alternative for heat in an outage is a generator unless you want to risk it all with a kerosene heater.

"There are also water type that us residential water pressure to run a pump that unless the city runs out of water, your basement will be dry."

Nopt that uncommon following a major flood, hurricane, or even a decent strength/size tropical depression.

The city water folks need power to pump and filter the water.
Once the large above ground tanks run low the water pressure goes away until they can be refilled.

Mr. Netwon's gravity is were the water pressure comes from.
No water in tank, no pressure.

One thing for sure, a water-powered backup sump pump has never cuaght a house on fire, battery backup with chargers have.

If for some reason you lose power from some horrible storm and the same storm knocks out the pumping station even in this little town of 900 people on a good day and the generator for the plant is not able to run either... I am sure there are already bigger problems to deal with than a wet basement.

Every system has it's pros and cons... I have thought about both and will probably do something after I finish more of my basement.

In 47 years, I've never lost water, but can't count the times I've lost electric. (I have a generator, and no basement)

The guys at wind and sun forum disagree with Mr havac -
Neil writes:
" yes people do it all of the time. .... in any case you need to know how much the total draw will be and for how long it will be needed to provide this backup power. once you find out that info you should add another 25% or so for inefficiencies in the inverter and charging inefficiencies. this power is in watts which is volts x amps. if the system isn't large you can go with 12v, but do be sure to size your wires correctly as too small of wires will introduce too much resistance and of course lessen the overall efficiency more. any way, when you decide on the battery voltage suitable for the system divide the watts by the battery voltage to come up with the amps. this figure must be doubled because you shouldn't drain the battery or batteries below 50% depth of discharge.
on the inverter's requirements, be sure to get a sinewave inverter and that it can take not only the constant power needed by the boiler, but also the surge power it will require upon startup. the surge could easily exceed several times the constant power the boiler requires even though it's to be for a few seconds. if you place other items on the inverter then it all must be figured into the requirements additively.
one more requirement would be a way to introduce or switch the inverter into the household circuits as most do not get connected to the grid. disconnects are fused and protect you from having multiple power sources active to the same wire. without this this could be as dangerous as connecting a generator up to the grid when it's not designed to do so. there are more costly inverters out there with grid tie ability and builtin chargers.
the charger is another consideration as without it the batteries would die. the charger should be a quality design and not a run of the mill automotive battery charger. it should have at least 2 stages of charging being bulk and float and not be less than 5% of the battery capacity. be sure of the maximum charge current the batteries can take as per manufacturer's specs as some cannot take more than 10%, but some do go higher. you don't want to exceed the manufacturer's max charge rate recommendations. i think this covers most of it and if you decide later on to want to add solar you could by buying and installing the pvs and an appropriate controller all wired to run parallel to the backup system just outlined.

NIEL

Here is a link that might be useful: Battery back up

I have a 1,500 watt inverter powered by a 4D industrial battery that is enough to run the furnace and the blower! I find that the inverter needs to have a bonded ground and a managed 60 hertz 115 volt AC current for my electronically controlled furnace!! This is good for the 10 hours at night even in sub zero temps! Then I start up my generator to power part of the house and charge the battery for the next night! Here in Tahoe we get several power outages a season some lasting a few days!

If you can get 3-4 hours of run time, then this is a very nice solution. Did you also wire in the transformer for the thermostat? That wasn't clear in the video.

My NG boiler(s) are in a convection hydronic system - large diameter pipes which go up to radiators and the water moves due to temperature difference (convection). No pumps. My old boiler had a thermocouple in the pilot light which generated enough power to open the gas valve when the thermostat called for heat. My new furnace (recommended because it's more efficient, according to the gas company) has some electronic controls which require 120VAC. When I lost power for 8 days due to Sandy, I got an inverter to drive the 120 Volt electronics from a 12 volt battery. It worked fine.

I didn't need to wire my thermostat in because the furnace has its own 24vdc transformer that is powering my thermostat. You could just wire that in with the battery instead as long as the volts are within the thermostat limits. I checked mine, it would work either way.

Quite a difficult question. I would be interested to know what you decided to do in the end. I don't know much about furnace systems, and if I have any problems, I immediately contact https://www.newfurnace-newac.com/get-a-quote-page-1/. These guys were recommended to me by my friend and I am glad that now they are helping me deal with all the problems associated with HVAC. So if you are still looking for an answer to your question, I advise you to consult them. I think they'll help you.

So I tried to run a test on the setup I had above, it failed!! I did a bunch of reading on hear and various garage forums, anyway, I found using an inverter was the right solution for me. It also passed a great real test and exceeded my expectations.

Two things: Isolate your system from the mains coming in or you are going to shock a linesman. Easy as turning the breaker to the furnace to off

Remove your previous video when you used the aps.

The latest setup shown in the last video does have power going to the on off switch outside of my furnace room, no power goes back from this setup even with the switch in the on position if the power is off.

My first setup may have been incorrect, the only way a shock is possible here is if someone was working on the furnace with the emergency shut off on.

Hi Bruce I just saw this post from 3 years ago. I would like to do similar to what you are describing. How do you convert your battery powered generator to A/C to take my furnace? Sorry electric novice. And do you recommend a different generator?

I use a pure sine wave inverter. Many will make the claim that they are but most are not... do some research when finding an inverter. For the record, the setup I linked in the video in this thread is still working.