Ask Experts Questions for FREE Help !
Ask
    Mackman88's Avatar
    Mackman88 Posts: 1, Reputation: 1
    New Member
    		  
    #1

    Dec 9, 2007, 07:25 AM
    Fan turns on and off rapidly, even with thermo off
    Hello and thanks to anyone that can help me!

    My furnace started acting up yesterday, I was wondering if its worth fixing, calling a repair person OR just buying a new one...
    First it is a 15 year old furnace, it's a Goodman model GMP 100-4

    what is happening is the fan cycles on and off even when the thermostat is off (I've replaced the thermo just in case and that didn't help) I don't mean it cycles every few minutes I mean it will turn on and off 3 times a minute and sometimes 3 times a second (completely random).
    I have checked all the wires and connections seem fine, no burnt wires.
    once in awhile it will actually run a regular cycle and heat up my home. Then it will go back into its odd cycling (don't think its to hot as its in my basement and its about 25F here).
    sometimes it starts a regular cycle and runs for 15 + minutes, other times it starts a cycle and the blower comes on at the same time the exhaust fan comes on.
    I have checked the temp of blower motor and its cold to the touch.

    Just seeing if I can get any tips/info before I spend a bunch of money.

    Thanks

    Mack
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
    		  
    #2

    Dec 9, 2007, 08:53 AM
    It could be the fan limit control. The fan part controls the blower on most older furnaces. If you turn the blower to on manual at the thermostat does the blower come on and stay on?
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Thermo disc [ 1 Answers ]

Hi can any one tell me how to read the temp of a thermo disc here are the numbers on the one I have 36TX11 21608 L190-55F 28P114-1 A0544 THANK YOU

Light turns on & Fan turns off automatically when a remot is installed [ 2 Answers ]

I bought a Hunter remote separately and installed to my ceiling fan. Everything works good except the following problem. I turn on the fan & turn off the light before I go to sleep and in the middle of night the light goes on and fan turns off. This happens a few times until morning when I turn...

A/C Seems to have power, no cooling, thermo weird [ 1 Answers ]

I have an Amana heating and airconditioning whole house unit. The unit is 3 years old. THe A/C has been running fine all summer. I came home today, after a poweroutage, and ther LCD thermostat has all of the characters lit. All of the time, temp, and incidators are all lit up. If I turn the swith...

New instal thermo 3 wires. [ 3 Answers ]

OK I just recently bought a honeywell thermostat controller. When I removed my old thermo (slider switch type with mercury) only 2 wires were connected, but a third wire was in my box still covered (not bare wire). One wire connected was white and the other red the 3rd odd ball was green. What...

Thermo stat wiring question [ 1 Answers ]

My LUX thermostat and wiring has a red wire and a white wire. My HEIL furnace is labeled R G W Y G. Does the red go to R & white to W? I'm not sure and don't want to cause any damage! Thanks for any help!

View more questions Search