Heil blower stays on

[dj1100rt]

I have a Heil, gas, condensor furnace. The blower stays on forever after a heat cycle. Model #NUGK100DH3. Is this likely to be the fan control and limit or the relay in that same circuit. Unit is a 1989 model.

Thanks,
Dave

[too tall terry]

if that model uses a fan/limit,it could be that,or it could be controled by the control board....if the control board is used,there are dip switches that can be set for your blower off delay time.....how long would you say the blower stays on after heating call is over?.....more than 3 mins?.......nothing meant by this, but when was the last time you had the furnance serviced?......it might be a good idea to call for service,and if a fan/limit is used,by all means do not attempt to adjust it yourself!!!!

[dj1100rt]

Fan stays on all day as the furnace cycles through many heat cycles. If I turn off the power at the main switch, after a heat cycle and the plenum has cooled, the fan, of course, goes out. As I turn the main switch back on, the fan will stay off until another heat cycle triggers it.

The furnace was serviced at the start of last year's heating season, probably a year ago this month.

Thanks,
Dave

[haaar]

Depending on what type of fan control Heil used that year, you have a bad relay on the control board, a bad fan relay, or a thermal fan switch.

As old as it is, I'll bet it is a thermal switch.

Sometimes those switches will collect dust over the years, and a good cleaning of the switch itself will bring them back from the dead.

[dj1100rt]

I've just replaced the fan relay and that didn't solve the problem. The fan stays on all day after the heat cycle is ended. (In the summer, I have the same problem with the air conditioning cooling cycle.)

Any ideas?

Thanks,
Dave

[beenthere]

Time to have it checked/serviced again.

[supernova72]

Is the filter clean? LOL

[mr subcool]

sounds like a setting in the thermostat to me. Or a control fan limit switch sticking

[marksatterfield]

I'm having a similar problem,

Thanks folks,

--Mark

http://www.marksatterfield.com

That was clearly a DIY question.
We are not a DIY site. Please read the rules, Thank you.
http://hvac-talk.com/vbb/showthread.php?threadid=1241

http://hvac-talk.com/vbb/showthread.php?t=186644

[catmanacman]

a service company will be able to find the problem and get the part to repair it and also check the condition of the unit why did the part fail ?