New inducer motors fail with three red flashes; old motor doesn't

[Givemeasec]

Last winter the inducer motor on my York furnace was running loud so I ordered a replacement. Put the new one in, but the furnace didn't start, and instead only repeatedly flashed red three times. According to York, this means that the pressure switch is stuck in the open position, but when I put the old motor back in the furnace kicked back on and worked again with the same pressure switch (though it was still loud). Since the furnace still worked with the old unit, I figured that there wasn't anything wrong with anything else in the furnace unit (like the pressure switch, vent pipes, etc.), so I sent the replacement motor back and asked for another one. Same result with that one (flashes red three times) and then again with a third motor (the third one was OEM with specs that match the old one).

I left the old one in all summer since I wouldn't need it but now that it's getting colder again I'd like to replace the old unit. Any ideas why new ones keep generating the three red flashes and the old one doesn't?

 

[user 4883]

Has the pressure switch ever been replaced or is it OEM?
Does the pressure switch have any adjustment to it?

 

[Givemeasec]

It's OEM. There doesn't seem to be any adjustment to it. I'm thinking of just replacing the switch (along with the motor).

 

[user 4883]

It's OEM. There doesn't seem to be any adjustment to it. I'm thinking of just replacing the switch (along with the motor).

Hate to see ya keep throwing money at the problem with no results.
Put a vacuum gauge on it an see what the difference between the two motors is.

 

[pjones]

Who matched the specs up when ordering a new motor? Sounds like the new one isn’t pushing enough air to activate the pressure switch. If it’s working with the old motor then the pressure switch probably isn’t the issue, in fact it sounds like it’s actually doing its job. You need to move enough air before lighting the burners to be sure there will be proper combustion.

Don’t get a generic replacement motor, get an OEM replacement assembly that includes the all the parts (gasket, inducer wheel, and collector scroll). I’m assuming you have been replacing the whole assembly each time, I mention it just to be sure.

There are other possible solutions too but there’s no point going there until we know for sure you have the right parts. It can make a big difference sometimes.

If that fails to fix the issue then post the make and model number of your unit and pictures always help too.

 

[Givemeasec]

Hate to see ya keep throwing money at the problem with no results.
Put a vacuum gauge on it an see what the difference between the two motors is.

Fortunately I haven't lost any money since I've been able to return the motors each time. I'll look into getting a vacuum gauge.

 

[Givemeasec]

Who matched the specs up when ordering a new motor? Sounds like the new one isn’t pushing enough air to activate the pressure switch. If it’s working with the old motor then the pressure switch probably isn’t the issue, in fact it sounds like it’s actually doing its job. You need to move enough air before lighting the burners to be sure there will be proper combustion.

Don’t get a generic replacement motor, get an OEM replacement assembly that includes the all the parts (gasket, inducer wheel, and collector scroll). I’m assuming you have been replacing the whole assembly each time, I mention it just to be sure.

There are other possible solutions too but there’s no point going there until we know for sure you have the right parts. It can make a big difference sometimes.

If that fails to fix the issue then post the make and model number of your unit and pictures always help too.

The first two motors I tried weren't OEM, but the third and last one was. I think it was a SupplyHouse rep who matched the OEM one. Amazon matched one of the others, based on my furnace. I'll post the part #s and try to get some pics.