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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22541
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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rheem 90 plus gas furnace. Not turning on. Checked the 3

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rheem 90 plus gas furnace. Not turning on. Checked the 3 troubleshooting lights. Both green led lights on solid. Orange led light not on. Tried shutting furnace off and on. No change.


My name is Billy.

What is the model number?

Customer: replied 3 years ago.

I'm not sure if it is not 90 plus... I've used this service once before for the furnace if you can locate it that way, or tell me where to look.

Thank you.

There are revisions throught the years,

Just aprox how old and we can started?

Customer: replied 3 years ago.

I am ready to start and it was manufactured in 1992 as best I can tell. Labels on panels have 92 prefixes... No obvious model number though

Thank you,

Can you tell me when thermostat is turned up and power is on...if there is 24v from terminal w to terminal c on the circuit board?

Customer: replied 3 years ago.

I have an analog volt meter from radio shack. New battery in it but I don't know how to read it. Switched it to RX 1K ohm setting and put connectors into the connection for the ignitor. Needle went from 0 (left) to far right... which I assumed means the connection is not broken on the ignitor.

If you can instruct me with that info I can check voltage on the terminals.

Do you have a volt setting, AC~?

Customer: replied 3 years ago.

Yes. Opposite side in red, AC with a V after it.

great...set to that...and then check an outlet to test.

verify 115v or so on meter

Customer: replied 3 years ago.

3 settings: 1000, 150 and 15. Which one do I use and do I simply insert the prongs into an outlet?

set to 150.

Then meter lead in each side of outlet

Customer: replied 3 years ago.

ok, I did it and the needle went to approx. 800 out of 1000 on scale. Also there is a dial on the side of the device. I have that about in the middle.

what is the make model number of the meter
Customer: replied 3 years ago.

Radio Shack volt meter. Only number on it says 05A06. Bought it some years ago, never used it. Dial on side says ohms adjust. Pretty cheap as I recall.

Ok on the 150 scale on the front of meter...there should be 3 different lines to follow and we want the 150 scale

what does that line read when testing with meter at outlet

Customer: replied 3 years ago.

Yes I had it set to the 150. Put the prongs in a wall outlet and needle went to 800.

Ok, at least we know it moves with ac power.

Now remove furnace doors and tape the blower door switch down.

Then turn thermostat to heat and up.

Then use meter to check the thermostat wire terminals on the board in furnace. R to c and W to c.

Customer: replied 3 years ago.

sorry for the delay. had to re-attach the ignitor. Checked both with gas on and off. both read about 200 on the acv meter of the scale. I also noticed that now the "ok" led was flashing twice in succession when I turned the system back on.

when you read 200 w to c was the exhaust fan running in the top that attaches to exhaust vent?

Customer: replied 3 years ago.

Nothing running at all. Hear slight buzz from panel. Read manual about the "ok" led chart about blinking twice. It says pressure switch stuck open.

correct...the pressure switch reads open because the exhaust fan is not turning on.

Can you try to access the exhaus motor to spin it to see if stuck?

Can you use meter to see if 115v is going to the motor?

Customer: replied 3 years ago.

Do you mean the blower motor in the upper compartment? It has an electric motor in front that seems abnormally hot. If so, I think I can remove the screws holding it in place to check it.

That is the one...hopefully something is just stuck in there...power off...
Customer: replied 3 years ago.

removed motor. wheel fan stiff to move but does. removing back casing to see if i can manipulate it more. Or would that be a waste of time?

can you get some oil down the shaft sides?

Customer: replied 3 years ago.

I will check. still removing back casing


this is your issue.

It obviously has power to it because it was hot.

But it was seized resulting in no air flow thus open pressure switch.

Get that motor freed up, oiled etc...and you may be able to save it. If not you will need to replace the motor or assembly.

I thank you for your extreme patience.


BillyHvac and 2 other HVAC Specialists are ready to help you
Customer: replied 3 years ago.

I replaced the blower motor, which is working, but still orange led light and no glow from ignitor...

Have you checked that the vent pipes are clear?
Customer: replied 3 years ago.

A little confused, sorry. Are you still working with me on my furnace?

yep on other thread
Customer: replied 3 years ago.

Too many windows open. It looked like it was ended so I closed it... If we could continue on this one please.

no problem

have you removed vent pipes and tried unit just to the point ignitor starts?

Customer: replied 3 years ago.

Exhaust disconnected at furnace exterior. Should I have the gas on when I attempt this?


Customer: replied 3 years ago.

I removed the vent pipe at the unit. Turned the system on both with the gas on and off. Good airflow leaving unit. No orange led light present. Same green code. No glow from ignitor...

Customer: replied 3 years ago.

You still with me billy?


Customer: replied 3 years ago.

billy I need to know if you are still assisting me or not...

I apologize for delay.

Have you poked the barbed fitting clear that the tube attaches to?

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