How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Heath Your Own Question
Heath
Heath, HVAC Technician
Category: HVAC
Satisfied Customers: 1034
Experience:  11 yrs. comm.resid. service, Type III Cert.
29994690
Type Your HVAC Question Here...
Heath is online now
A new question is answered every 9 seconds

Lennox Elite series furnace. 80% efficient. Red light is flashing

Customer Question

Lennox Elite series furnace. 80% efficient.
Red light is flashing slowly. Green light is on steady.
I changed batteries in wall thermostat. I used steel wool on flame sensor as last fall I had an issue and
the flame sensor cleaning fixed it.
This fall the furnace does not seem to light at all.

From, Gil
Submitted: 6 years ago.
Category: HVAC
Expert:  Heath replied 6 years ago.

Heath :

Hello my name is Heath it will be my pleasure to assist you. The slow flash is normal operation when you switch the thermosttat on does the ignitor com on and ignite the furnace?

JACUSTOMER-5rzv6pee- :

No it does not ignite.

JACUSTOMER-5rzv6pee- :

I thought both the red and green light have to flash slowly for it to be in normal operation? Am I wrong?

JACUSTOMER-5rzv6pee- :

1

Heath :

That is right I had to verify what board was in the furnace. The problem is in the vent pressure switch alot of times when the sit over the summer the hose or the nnipples that the hose hooks to gets gunk in them. Locate the pressure switch and pull the hose off clean the nipples that the hose attaches to and blow through the hose. Attach the hose to the vent pressure switch and lightly suck and blow on the hose to see if you can hear a click if you do then switch is okay. Re-attach the hose and turn the power off to the furnace for a few seconds and then turn it back on to see if the unit will fire up.

JACUSTOMER-5rzv6pee- :

Heath I replied to your email with a photo. I am trying to find the pressure switch and hose. I think it is the square orange hose. Is that correct? I was only able to get the hose off of the top side (the switch side) it seems clean and nipple seems clean as well.

JACUSTOMER-5rzv6pee- :

The hose is clean as I can see right through it. The pressure switch seems to work when I suck and blow on the hose when connected to the switch. I will shut off breaker for a few seconds and then turn it back on to see if unit will fire up.

Heath :

okay let me know.

JACUSTOMER-5rzv6pee- :

Not working. Again only the blower starts up and just blows the cold air.

Heath :

The inducer motor that attaches to the exhaust pipe doesn't come on? If not then that is the problem the exhaust motor has to come on to make the pressure switch then turns on the ignitor.

JACUSTOMER-5rzv6pee- :

Do you mean the combustion air blower?

JACUSTOMER-5rzv6pee- :

If so are you saying it has to be replaced or can I do something to make it work??

Heath :

Yes I am talking about the combustion blower. Sometimes they get stuck in one spot from sitting if you spin the blower by hand and get it freed up it will run again.

JACUSTOMER-5rzv6pee- :

The combustion blower was and is moving freely. I spun it by hand.

Heath :

Does it come on with the furnace? When it should be lighting?

JACUSTOMER-5rzv6pee- :

Combustion blower does not come on when furnace should be lighting.

Heath :

Okay then the problem is either the blower motor or the circuit board. Disconnect the wires going to the blower and using an electric meter chech the wires for power when the furnace should be lighting if you get no power to the wires from the circuit board then the circuit board is bad and not sending power to the motor if there is power to the motor then the motor is bad and you will have to replace the inducer motor.

Heath :

If I helped you in any way could you please hit the accept button so I can get paid for my time.

JACUSTOMER-5rzv6pee- :

Hi Heath, the furnace is not working. If I hit accept can I still get your help if I want it?

Heath :

Yes I always leave my questions open till the customer is satisified.

JACUSTOMER-5rzv6pee- :

Hello Heath, sorry for the delay in getting back to you but many reasons.

JACUSTOMER-5rzv6pee- :

Hi again Heath, I had to wait quite awhile to get a HVAC expert to come to my house and figure out what was wrong with my furnace. He figured it out very quickly. It was the 160 degree Limit switch that was not working. He ordered and sent me a new 160 degree Limit switch. I easily R&R'd it and then the furnace worked properly. I did not receive info from you about the 160 degree limit switch and therefore I am thinking I should not pay the money as it cost me money to get the HVAC expert to travel 25 miles one way to come to my house. What I do blame is that your manuals did not lead you to tell me about the 160 degree switch. I thank you for your time and hope to hear a response.

Heath :

Thats fine glad you got it fixed.