[Cribb508]

Rheem Criterion Furnace fan keeps coming on and off constantly with a loud noise. Can someone please help me?
Paul::confused:

[NorthernHeat]

What do you mean by constantly? And can you better describe the noise?

[Cribb508]

When the fan comes on, it goes on and off, about 5 to 6 times in a row, about a minute between, before it stops and it sounds like a train. It does not heat the air long enogh for it to be effective, until I turn up the thermastat and then it comes on every 15 minutes or so, going on and off until the whole house is overheated.:o

[hvac1000]

Bad fan switch. Out of calibration. OR the main orfice could be restricted not allowing the furnace to heat up properly to maintain temp for fan switch to operate properly.

[NorthernHeat]

I wonder if the blower motor is going out on thermal overload. This would be the visual sequence if this is the case. Start heat cycle, burners ignite, about 60 seconds later the blower starts, blower runs 1 minute (it over heats and goes out on thermal overload) the burners still run, sometimes they cut off before the fan comes back on again and sometimes they don't. The noise could be bad bearings or the rotor scraping against the stator.

For all to know.
Good filtration is the best answer to a long lasting blower motor.

[Cribb508]

What is the main orfice called? What can I get checked out or replaced?. if this is the case? Thanks Guys :confused:

[NorthernHeat]

There is no main orifice? There is an orifice for each burner. What is the model number? A Criterion is not that old of a model. It has 2-6 burners depending on BTU. Lets say it is a RGRA-100EAMER. It would have 4 burners one orifice each. There is a main limit but no thermal blower control, blower is controlled by a timer built into the PC board.

[Cribb508]

Model Number # RGDG-075AUER , 75,000 BTU.

[NorthernHeat]

OK, so did you observe the operation? Does it act like I said it might? After the blower turns off unexpectedly, put you hand on the motor, is it to hot to touch?

[Cribb508]

Yes you are right,. what should I do about this?;)

[NorthernHeat]

Replace the motor. It has to be a Protech motor because the legs screw onto the motor. You can call local Rheem dealers to see if they will sell you one from there store, or you can pay a service tech to do it for you.

[Cribb508]

Thank you Northernheat,. for your time here today. :) I will try this.

[Cribb508]

Just to let you know, I did a thoughrow inspection, and it is the inducer motor that keeps going on and off, at the same time the burners ignite. What keeps telling this thing to come on all the time? Its so loud!!

[hvac1000]

Replace the motor.

[Cribb508]

Ok thanks you guys,. I think this is a fantastic to get help like this. I support NorthernHeat:) Thanks again