What would cause a gas furnace to draw too many amps?

What would cause a gas furnace to draw too many amps?

Exactly what do you mean by too many amps? As in it blew a fuse??? That is a short circuit, look for burned transformer, overheated motor, etc.

Stalled/jammed blower fan motor?

Can the blower turn freely? I had a bearing failure in one many years ago, it seized. Interestingly, it didn't trip the breaker, and the blower motor didn't burn out...which was good because I couldn't find replacement bearings and had to rebuild it from parts I scavenged off another similar old blower that a shop had removed when replacing a unit. I think I handed the shop owner a couple of bucks for the old unit, other than that the repair was free.

Anyway, I'm assuming blower because it is the biggest amp draw. The second biggest user would be the induced draft fan.

quote; The second biggest user would be the induced draft fan.

It may be the "second biggest draw", but it still a "Very small" one. We would have to know what he means by "excessive amps" and how he determined it.

Merry Christmas everyone! I'm helping my sister-in-law with this issue. I'll try to find out what the amp draw was according to the repairman. No one available til Tuesday. She said they got the furnace running but did not know how long it would last. Right now, I've very limited information. Thanks for your inputs thus far.

If the voltage was marginal (say in a brown-out), and things were 'on the edge' of accepability, it could draw excessive current and trip or blow a safety device. When I had my air handler/a-c unit installed, I installed a low-voltage cutout device. I think it was made by IDS. It's about the size of a deck of cards, has some controls on it to set the desired operating range, some LED indicators, and an internal relay to disable operation if the power is outside of parameters you set. No idea if it has saved my system, but it also has a time-out after power outages to prevent operation immediately after power reapplication when it can fluctuate radically for a few moments or so, thus further protecting things while the voltage is all wacky until it stabilizes. The internal motors probably would be okay, but the unit has at least a couple of circuit boards, and not asking them to operate until the power is stable is probably a good thing.

kailor said:

Merry Christmas everyone! I'm helping my sister-in-law with this issue. I'll try to find out what the amp draw was according to the repairman. No one available til Tuesday. She said they got the furnace running but did not know how long it would last. Right now, I've very limited information. Thanks for your inputs thus far.

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Sounds to me that the service man, was blowing a little smoke. Maybe not.

It is very disturbing how they take advantage of the unknowing. Maybe he spoke the truth. who am I to judge.


If she called because of a blown fuse, then Jim's answer makes more sense than mine.


Have a happy Holiday.

The blower motor was bad.

kailor said:

The blower motor was bad.

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We appreciate that you came back and gave us the outcome. Sounds like the service man knew what was up but just didn't explain it very well. Motors do go bad, and hopefully this did not cost you too much...maybe an arm and just one leg, not both!!!