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T87 thermostat heat doesn't stay on long

My gas furnace is constantly turning on (2 minutes) and off. Is there some kind of setting (maybe the delay setting) that I need to change so that it will stay on longer.

This can't be good for my heating bill and I know it's not good for the comfort level in my home.

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  • indy_deb Dec 19, 2008

    Appreciate your help. The way you described the location of the heat anticipator helped a great deal. Thanks so much for taking time to help me out with my heating. Happy holidays. d

  • Anonymous Mar 16, 2014

    I have a constant flashing code light. code on door panel says call for heat??


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Is this truly a T-87 round mechanical or is it the new electronic version? If it is gold in color it's the old tried and true, if it's white it could be either. Pull the outside ring straight out. If it is a t-87 mechanical you will see a mecury bulb setting on a spring on top. On the lower righ (4 to 5 o'clock) is a heat anticipater adjustment. Take the brass poiter and slide it to the left as far as it will go this should increase the duration of cyles and make them less frequent. This is if the problem is truly thermostat related. If it is the electronic version of the T-87 and it displays this behavior only when it is very cold out, it is a programming glitch that they were informed of 2 weeks after it came out, because I told them. If this is what you have purchase a new thermostat and replace that junk that is defacing your wall.

Posted on Dec 18, 2008

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