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

    Nov 1, 2007, 05:42 PM
    Fan Limit
    I have an older furnace with a Honeywell fan limit switch. The unit ignites, heats up and then the fan comes on normally. When it gets to the proper temperature the heating unit shuts down and the fan continues to run, as it should, as the unit cools down. The problem is that the fan doesn't shut down and the heating unit fires up again regardless of if it's at the proper room temperature or not. This seems to cause a continuous heating cycle and really eats up the natural gas bill.
    Any ideas are appreciated


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

    Nov 1, 2007, 05:53 PM
    Could be a fan and limit control they do go out of calibration. Also it could be the thermostat heat anticipator setting.
    T-Top's Avatar
    T-Top Posts: 1,871, Reputation: 100
    Ultra Member
    		  
    #3

    Nov 1, 2007, 06:23 PM
    The fan limit control switch controls the temp of the on and off the blower with a limit if the blower doesn't come on it kills 24v or 115v to the unit to shut it down. But a stuck or weak combination switch will not make it call for heat. Is it heating your house above the set temp, or is it just running a lot? If you have a lot of air leaks around the windows and doors you will get the same symptom.
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!

Fan limit switch [ 2 Answers ]

I need some help understanding the operation of a fan limit switch. What's the sequence of operation of this object. And how do one troubleshoot this part to determine if it's performing as it should. Thanks!:confused:

Fan limit switch temperature settings [ 2 Answers ]

What are the normal temperature settings for the fan limit switch on the a/c+gas heater blower unit?

Beach Fan Limit Switch [ 1 Answers ]

Have a gas Beach furnace with fan limit switch issues. First time the blower would not shut off and blew cold air in the end. Replaced fan limit switch and it worked for a month and then did the same thing. Next time it lasted for nearly a year and same thing over. Now with a new one it works and...

Fan Limit Broblems [ 1 Answers ]

I got some problems with the Fan limit. Ever time when I replace him it works for a couple days then it goes bad again. What might cause that problem?

Replacing a fan limit control switch [ 1 Answers ]

I have a York gas furnace that is about 18 years old. The fan is blowing continuously. Tried to replace the thermostat and it didn't correct the problems. I am assuming the fan limit control switch is bad. Can I replace it myself? It is a Honeywell switch. Should I remove it and take it with me to...

View more questions Search