Question about Heating & Cooling
Sounds like the blower motor is getting hot and cycling on internal motor overload. Probably airflow or the blower bearing or capacitor. Turn off all power to the unit then you need to check the filter, Evaporator coil to see if air is getting through it. When checking the coil for a blockage you need to remove a side plate, it's triangular and check the entering air side of the coil to see if its blocked. You need a volt ohm meter with a micro-farad scale to check the blower capacitor and motor amps. You could have a bad motor bearing.
Posted on Feb 19, 2019
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
You have a flame sensor that may just need cleaning take out and take fine sand paper or emery cloth and clean
Posted on Nov 30, 2008
This just sounds like a couple of problems. First, your blower is designed to only turn on once the heat exchanger heats up, so the flame will be on for a minute or two before the blower starts. it sounds like your blower is cooling down the heat exchanger too fast and causing it to shut off so it can warm up again...check blower speed for heat, it should be the lowest speed (black wire). Blue=medium speed, red= high speed. second problem could be your flame sensor rod is calcified, you just need to locate this and clean it off with some fine sand paper.it is located in the flames near the burners. Also change your filters, for proper air flow through your heat exchanger.
Posted on Oct 28, 2009
I have a Lennox G40UH furnace. The burners fail to ignite about every 5th time. The furnace will try to ignite the burners then shut down. Once in a while the temp will drop down to 62 then fire up. I have only gotten a Diagnostic code once "Watchguard - burners fail to ignite" once I shut the power down and it started.
The furnace is clean, 5 years old, the flue is not clogged.
Posted on Jan 03, 2010
hi check out the temp rise and fall on the fan control see if he has left the blower in the summer swich postion where it runs all the time
Posted on Feb 12, 2010
SOURCE: furnace short cycles
You could have a bad overtemp sensor which is activating at too low a tempreture. They should not be that expensive. I would just replace it to eliminate the control if it is bad. It is a small metallic disc attached to the heat excanger. Has two wires coming off it. Approximately 1 inch in diameter. Usually on the front of the heat exchanger. It should have the tempreture that it activates at stamed on it. The temp is probably in celceus. Prior to replaceing it you could determine the activation temp and if you have a thermometer, or better yet an infared thermometer, check it while running to see what temp it activates at. If it is bad it will activate at too low a tempreture and should be replaced. Let me know if you need anymore help.
Thanks for using FixYa
Posted on Feb 23, 2010
Tips for a great answer:
Aug 23, 2017 | Heating & Cooling
May 14, 2010 | Goodman GMS90703BXA Heater
Jan 17, 2010 | Heating & Cooling
Oct 14, 2009 | Heating & Cooling
Feb 15, 2009 | Heating & Cooling
Jan 06, 2009 | Heating & Cooling
Dec 12, 2008 | Honeywell Electronic Programmable...
687 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: