GMT070-3A model was working just fine last winter. This winter it will not turn on. There are 3 blinking lights. Only yhing that changed was we had new roof and I got roofer to come check to make sure...
Hello. I can assist you. Let's begin with the pilot light. The most common reason a furnace pilot light keeps going out is the thermocouple is placed too far from the pilot light. The thermocouple is a sensor inside a steel sleeve that sits in front of the pilot light. The pilot light must heat the thermocouple so the thermocouple can keep sending an electrical charge back to the furnace, which keeps the gas valve from shutting closed. To that end, the pilot light should be adjusted so the flame it gives off is at least two inches long. Should it still keep going out, the thermocouple is faulty and needs to be replaced.
This alone may be all you need. However if after you get the pilot lit you still have the blinking lights, read on. you also may have an internal overload on the motor that opened .you can also check the motor itself by first shutting off power to the unit and physically cut the 2 power leads wire feeding the motor and OHM out the motor if you get no reading the motor is opened internally and bad ,you can check the motor to ground to check for a short.take one meter lead and attach to a good ground on the motor and the other check one motor lead at a time if you get a reading your motor is bad .you should not get any readings ( look at the wiring diagram ventor motor it should show a capacitor ,if it has one.)Capacitors are usually mounted next to or near the motors. not far away.Sometimes they have them strapped right on the motor inside a metal box.If you don't see a lump at the motor itself doubt it has a cap. also the wiring diagram will clearly show if it does. I'm sure if you look at the wiring diagram for the indoor blower motor it will show it.
If indeed you have one ( cap. ) the only way I know how to check it would be with a NON digital ohm meter the old style ones that have the needle deflections ( unless you have a capacitor tester ) remove capacitor and short out the two terminals to each other. then clip one end on one terminal other touch the other side. (OHMS scale) if you get a needle deflection then it drops back to the left side the cap. is good. (you may have to adjust the ohms scale to get a middle of the meter reading.If the needles pegs in the opposite direction you need to reverse the two meter connections. everytime you want to check the cap. you need to short the cap. terminal together I use a screwdriver holding the insulated handle and having the metal shaft of the screwdriver touch the cap. terminals.
if you get no meter movement the cap. is bad. if you get a needle movement but it goes to the opposite side and never returns then its shorted and no good . all you want is to have the needle move up then drops out and goes back. that tells you that the cap. is discharging from one side to the other to help start the motor.
Your unit is Manufactured by GOODMAN and as far as I know they have one of the better warranties out there.If you determine it is the motor Goodman bumped the warranties from 5 years parts to 10 years parts in 2006 or 2007 .
Also where is the operating instructions for this unit? last Goodman 90+ condensing furnace we installed had all the codes ( blinking lights and TROUBLSHOOTING GUIDE ) inside the install guide. So I would say to you is whoever installed your unit get the install guide from that company, person. Good luck with it.
Oct 25, 2009 |
Goodman GMS90703BXA Heater