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Douglas, HVAC Technician
Category: HVAC
Satisfied Customers: 3089
Experience:  Manufacture Rep for Major Brand, Technical Trainer, NATE
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My Luxaire furnace will not run. I am getting 3 blinking red

Resolved Question:

My Luxaire furnace will not run. I am getting 3 blinking red lights, which indicates pressure switch open. If I take the smaller air tube off of the bottom of the burner box and blow into it (into the pressure switch), the light will go back to green, but then back to 3 red shortly after I stop blowing into it. Also, if I take off the bigger air hose off from the exhaust gas blower and suck on it, the light will go green. The exhaust gas blower is also making some pretty loud noises, like fan blades rubbing. Do you think I have a bad pressure switch, or could it be the ex. fan causing improper pressure switch operation, and what would the approx. replacement cost for each component? Thank you. Pete
Submitted: 7 years ago.
Category: HVAC
Expert:  Douglas replied 7 years ago.
judging from what you are suggesting, if the fan is making alot of noise, it's probably the fan itself. If it touches the inside of the housing, it will slow down and lose pressure. If the wheel has rusted it may be coming apart.

You will need a model number of the furnace or a part number from the entire venter assembly. Usually you cannot replace just the motor as you cant get the wheel off and without the wheel coming off, you cant get it out of the housing.
Customer: replied 7 years ago.
It is not the (electric) motor that is making the noise, it sounds like the impeller blades of the blower itself. there are four mounting screws/nuts that hold the motor onto the blower housing, that looks like it would come off so I could then remove the blower itself. the blower does not appear to be slowing down significantly, just making a rubbing noise as it spins. The unit is only about 2 years old. Should I start with the pressure switch replacement (i'm sure a much cheaper part) and see if that fixes the problem and then go to the blower unit if it doesn't? Any idea on cost for either of these parts?
Expert:  Douglas replied 7 years ago.
yes, the wheel inside only needs to slow down a few rpm to lose the airflow bu rubbing on the housing. You can take the nuts off, but the wheel is likely still connected to the shaft.

If the unit is only two years old, the whole assembly should be under warranty, why buy the parts? granted you will have labor to pay but the parts are covered through the contractor who submits the claim to his distributor.

Again you need a model number of the furnace before you know what parts cost.
Customer: replied 7 years ago.
The furnace came with the house which was bought 2 years ago. the furnace was supposedly replaced just prior to purchase of the house. How long are they warrantied for, and how would I obtain warranty service with no paperwork? Also, the manafacture date on the furnace is 2005.
Expert:  Douglas replied 7 years ago.
most have a 5 year parts warranty, so if it was built in 2005, you should be ok.
Douglas and 3 other HVAC Specialists are ready to help you
Customer: replied 7 years ago.
Thank you.
Expert:  Douglas replied 7 years ago.
Your welcome...