Ask Experts Questions for FREE Help !
Ask
    Powerlock's Avatar
    Powerlock Posts: 5, Reputation: 1
    New Member
    		  
    #1

    Feb 9, 2012, 03:19 PM
    Fan control on thermostat not working
    Thermostat ON switch does not turn on fan
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #2

    Feb 9, 2012, 04:09 PM
    Is there a wire from the g terminal on the stat to the g terminal on the furnace control board? You need one for the fan on option of the stat to work.
    Powerlock's Avatar
    Powerlock Posts: 5, Reputation: 1
    New Member
    		  
    #3

    Feb 9, 2012, 04:19 PM
    Yes there are 5 wires going from the stat to the furnace control board. W,R,Y,C, and G terminals The stat is a Filtrete 3M-50
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #4

    Feb 9, 2012, 04:21 PM
    Okay. Start at the stat. Jump r to g and see if the blower kicks on. If not, go to the furnace, and jump r to g (make sure blower door safetly switch is pushed in so you have power to the unit). If still no fan, then your fan relay or control board is bad. Let me know what you find.
    Powerlock's Avatar
    Powerlock Posts: 5, Reputation: 1
    New Member
    		  
    #5

    Feb 9, 2012, 04:35 PM
    Jumped r to g on stat,no fan. Jumped r to g on furnace with blower door safetly switch is pushed in, no fan. Fan runs when furnace heat is on.
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #6

    Feb 9, 2012, 04:55 PM
    Now, what wires from the blower motor hook to what terminals on the control board. Also, what brand and how old is the furnace? One step at a time here.
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #7

    Feb 9, 2012, 05:17 PM
    Im about to go eat dinner and relax with my girls, so I may not get back till tomorrow after work. Let me know what you find, and I will do my best to help out.
    Powerlock's Avatar
    Powerlock Posts: 5, Reputation: 1
    New Member
    		  
    #8

    Feb 9, 2012, 05:36 PM
    Furnace is a Lennox G20 series 10 years old. Wires from motor are white=Neutral Brown,Red,and Black=D Yellow=H
    Attached Images
     
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #9

    Feb 10, 2012, 04:34 PM
    All right, here goes. THe A terminal is the cooling speed, the H is heating speed, the CF is the continuous fan (which is the one you want to put the red on). The D terminals are dumby terminals which aren't wired to anything in the board (just a place to put unused wires). So, put your red (low speed) on the CF and you should be all set. You must not have central a/c? Just assuming since nothing is hooked to the cool speed terminal A. If you don't have a/c, you can put the black wire on CF instead of the red and you will get high speed vs low speed. However, I would start with red and see if you are happy with the airflow. Please let me know how things work out.
    Powerlock's Avatar
    Powerlock Posts: 5, Reputation: 1
    New Member
    		  
    #10

    Feb 10, 2012, 05:29 PM
    Placed the red wire on the CF terminal. Fan is on THANK YOU
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
    		  
    #11

    Feb 10, 2012, 07:17 PM
    Glad it worked. Take care
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!

Thermostat: Install an extra external fan control on are and G? [ 1 Answers ]

May I safely install an external switch to the fan control in my thermostat? Would this be the R and G terminals? (The purpose is to have (fan only) circulation increased in the house, controlled by a digital timer that opens and closes a relay switch throughout the day/night for short 1-3...

Working the celing fan without remote control [ 1 Answers ]

Hi, We moved into this place, and found the ceiling fan not working, though was told it's remote controlled. We have no remote control for the fan nor does the fan work when the switching... only the lights would come on (using the light switch)(the fan switch is separate). We've taken the fan...

How can I add fan control for my thermostat [ 1 Answers ]

I used to have a covensional 2 wire mercury thermostat and have recently upgraded to a digital thermostat that supports more options including being able to turn the fan on automatically. I want to be able to turn just the fan on and not the whole furnace so I can get better air circulation in...

Wiring fan from thermostat to control board? [ 10 Answers ]

Hi all. I just installed a new thermostat thinking this would solve my problem of not being able to engage the fan using the old thermostat (using "on" or "auto".) I was wrong. I'm getting the same behavior with the new thermo. According to another HVAC forum, it turns out the reason I...

Carrier Thermidistat Fan Control Not Working [ 1 Answers ]

The fan control on my Carrier Thermidistat does not turn the blower fan on when the Fan button is set to On. In Auto, the fan will not operate the fan on either a heating or cooling cycle with my heat pump. The fan DOES work when the furnace operates in emergency mode which is being controlled by...

View more questions Search