I have a 1987 Byrant Plus 90 furnace. The other day the wheel on the inducer motor lost a couple of blades. I replaced it installed a new wheel and the motor. Plugged everyhting in but the pilot light would not stay lit. I removed the cover cleaned the pilot light area and the gas orfices. The furnace will light and cycle when the covers are off. But once I put the covers on it will not relight. I removed a small amount of debris form the exhaust pipe, which had water in it. Does anyone have any ideas why my furnace will not relight?
Thanks

This is a model 398... A or B? Sounds like an obstruction in the combustion air intake. Check the strainer in the top of the burner box by removing the pipe on top, also check the vent termination outside. Use a shop vac if possible to suck out the intake and exhaust pipes. It would also be a good idea to flush the condensate trap (located on the front of the blower) to assure the secondary heat exchanger is not flooding. Let me know...

Thanks for the quick response. I did clean the intake screen on top. I am now in the process of trying to remove the intake pipe to check and clean. I'm just trying to figure out why this relight problem would start exactly the same time the inducer motor wheel broke. Hopefully just a coincident and the vibrations of the out of balance motor did not cause some other problem.

Another thought... did you find the vanes that ejected from the old inducer wheel? If they collected in the inducer housing outlet or exhaust pipe, they could be spoiling the flow through the exhaust vent, preventing the pressure switch from engaging. Did you notice a sulfuric odor when changing the inducer? This might indicate a restricted secondary heat exchanger. More info available at furnaceclaims.com.

I found 1 of the 3 blades. I looked everywhere and could not locate the other 2 blades.
The furnace will relight and operate if I take the little inspection glass cover approx. 2" across out of the door for the pilot light/burner housing. Also I have to leave the top cover off the furnace. It's like the pilot light is not getting enough oxygen.

I would be more suspicious that the pressure switch is not engaging when the covers are in place. A voltmeter connected to the p/s would be useful to determine if this is the case. Try this: put the covers back on and remove the air intake pipe from the top. Start up unit, wait until unit preheats and blower starts, then reconnect intake pipe. If burners drop out, the pressure switch is re-opening.

When I take the intake line off, the furnace seems to operate properly, (with all covers on)
I have removed the intake line to inspect for any obstructions, there are none.
Any ideas? Thanks