Generators and Electronic Furnace Controllers

I live in St Louis and just got power back after losing it for four days for the second time in one year.

The first time was in the summer and was merely inconvenient. This time I had to have a way to keep the furnace running. I first borrowed a generator (3550w), but I started feeling bad about putting so many hours on someone else's unit and figured it was time I had my own so I went out and bought a Coleman

5000w with the Suzuki 10hp engine.

Problem (with both but more so with the new one) is that generator power is not clean enough for my new-fangled electronically controlled furnace (Trane hv-80). With the borrowed unit the board kept flashing an error code that basically indicated to replace the controller board. Fiddling around with it for a while and I was able to get it running. With the new one the glow igniter comes on and apparently causes enough of a voltage fluctuation to disrupt the controller board and I get a "check igniter" error code.

Do other people have these problems? Between the midwest and the gulf coast we certainly have plenty of people who occasionally have to run on generators and electronically controlled furnaces are pretty much the norm now. Is my Trane just being particularly fussy? Everything else we powered off the generators ran great.

Of course the "cover our ass" page of the generator manual suggests getting a line conditioner for just about anything that's not a light bulb. Do I really have to drop a few hundred more dollars on one of those just to get my furnace to run?

By the way, what convinced me that this was the problem was that the furnace fired right up when I temporarily ran it thought my computer UPS. The UPS alarm squalled like hell because it wasn't big enough, but the voltage as measured with my voltmeter held much better and the furnace lit up. It would be nice if I could isolate the power to run the controller board from those that pull major amps so I could just get a conditioner for that, but it looks like everything hooks straight to the board so I don't know if that can be done.

Naturally, four hours after I got the new generator running the utility company got our power back up. I would still like to get a handle on this before the next time.

Reply to
Rick Brandt
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It could have been something as simple as the generator/s weren't grounded properly. The new stuff with circuit boards are very finicky when it comes to a good ground. Bubba

Reply to
Bubba

Are you just talking about earth ground (rod) or does it need to be grounded to the safety ground in the house?

Reply to
Rick Brandt

I second that opinion. I live in an area of the U.S. which had an extended power outage affecting several hundred thousand homes earlier this year, and our climate is, like many cities in the Northeast, very cold in the winter. Many homes with high efficiency newer furnaces had generator incompatibilities, but inadequate generator grounding was an extremely common problem which caused many furnaces not to work properly.

It is not surprising that permanently installed generators like my Generac Guardian require an 8 foot long solid copper 5/8th inch diameter rod to be driven into the ground and bonded electrically immediately next to the generator.

Smarty

Reply to
Smarty

Well that's good to hear. The next time (knock wood) I'll hopefully have fewer problems. That'll be Murphy at work of course. Ameren claims these are the two worst storms in their history as far as customers losing power and they happened just a few months apart. Now that I'm prepared a little better my generator will likely just gather dust.

Reply to
Rick Brandt

If you don't mind modifying the furnace controller, I'd try running the power to it through a quality line filter (not conditioner and not just surge suppresser) and locating the DC power supply on the controller and piggybacking a larger filter cap. By keeping out line noise and providing better ripple control on the DC power you might be able to convince it that the generator is ok.

Pete C.

Reply to
Pete C.

I bit the bullet and installed the Generac after two extended outages without heat, light, etc. Even if I never need it, the peace of mind is worth the investment.....

Smarty

Reply to
Smarty

Put some fuel stabilizer in the tank (Sta-Bil or something similar) and run it for a few minutes before you store it -- we failed to do that after the last time we used the generator about 2 years ago, and then last Friday when we needed it, we couldn't get it started. :-( Took apart the carb, cleaned it with solvent and then compressed air, reassembled... and all was well. But it's a pain in the neck that could have been avoided with a stabilizer in the fuel tank.

Reply to
Doug Miller

Its like anything else. If it is used infrequently and is important, you need to put it on a schedule. It should be operated XX amount of minutes every week/month. You dont put your car in the garage, let it sit for 2 years and then expect it to run when you need to go get a pack of smokes, do you? Bubba

Reply to
Bubba

Were these wired with two wires from the generator to the furnace or three?

Reply to
Stormin Mormon

Both. Of course, if you wired the furnace into your generator using a three wire cord (third wire being ground) that should take care of it.

Reply to
Stormin Mormon

Circuit board off the UPS and blower off the generator? You'd have to do some serious wiring, to make sure the two powers don't meet.

Reply to
Stormin Mormon

I like to run em dry.

Also, for hard starts, sometimes some ether sprayed onto the air filter helps.

If you remove the spark plug and spray ether into the spark plug hole, you turn a $500 generator into a $75 hunk of scrap to sell on Ebay. A relative of mine had this happen.

Reply to
Stormin Mormon

Jake, do you want this one?

Reply to
Oscar_Lives

WD-40 has (at least it used to have propane) as the propellant...

With Stormy's 'help', just about anything is possible...

Next time, suggest simply dip the end of the spark plug into the gas tank and then quickly replace it.

Reply to
PrecisionMachinisT

The best solution is to run the carb dry by turning the gas off at the tank and letting the unit run until it quits. The other poster's advice about periodically running it is a good idea as well but you can get by with just starting it a few times a year. You do need to put stabilizer in the tank if you are going to leave gas in it for more than a few months. But even with stabilizer it will not last forever and eventually should be drained. I run mine twice a year and if I reach the end of the year and have not had to use it I drain the gas from the tank. I also keep a 5 gallon container of gas with stabilizer in it around. Periodically I use that gas in the lawn equipment and replace it with fresh gas and stabilizer. That way you are ready to go whenever. Usually you have some advance warning but not always. I've had mine for about 8 years now.

I have not had the problems you are hav> >

Reply to
jamesgangnc

Millions of BIG UPS are tossed every year because the batteries are expensive.....

so find a used surplus LARGE UPS, plug in generator and try it in advance of next outage.

cheap solution you really dont nreed the battery just the conditioning

Reply to
hallerb

The main panel has a proper ground

Reply to
Noon-Air

Who said anything about a UPS or separating power? I didn't say that. I said to run all the power through a quality filter block (~$20 surplus) and to add an additional filter cap to the controllers DC supply. The filter keeping out spikes and hash and the extra cap reducing ripple should make the controller happier with generator power. Void the controller warranty of course.

Pete C.

Reply to
Pete C.

Yes, it does.

I'm wondering if he has tried to connect directly to the furnace with it disconnected completely from the main. Not just with the breaker off. In that case he probably does have a floating ground at the furnace. If you just turn off the breaker and connect the two hot and the common from the generator to the furnace then the main panel will give you an earth ground and tie the common and ground together. Not exactly the way you should do it but it should work and you would not have a floating ground.

There is a mechanical lockout available for several brands of ma> > The best solution is to run the carb dry by turning the gas off at the

Reply to
jamesgangnc

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