Go Back  DoItYourself.com Community Forums > Heating, Cooling, Air Conditioning, Ventilation and T-Stat Controls > Gas and Oil Home Heating Furnaces
Reload this Page >

York 80 goes through heat cycle but fan continues to run once temp is reached

York 80 goes through heat cycle but fan continues to run once temp is reached


  #1  
Old 01-06-20, 07:16 PM
J
Member
Thread Starter
Join Date: Jan 2020
Posts: 4
Received 0 Votes on 0 Posts
York 80 goes through heat cycle but fan continues to run once temp is reached

I searched these forums but couldn't find my problem.
I have a York Diamond 80 (about 20 years old)
model #P3HUA12L04801A
The furnace runs through its normal heat cycle. Once it reaches temperature it shuts down except for the main blower. It continues to blow cold air through the house until I cycle power to the furnace.
When the furnace is blowing cold air after the heat cycle the control board LED flashes continuously. The control board cover indicates this is FLAME - NO CALL FOR HEAT. I checked the high limit switch and it is working as it should.
What else should I check?
Thanks
 
  #2  
Old 01-07-20, 03:56 AM
B
Member
Join Date: Oct 2015
Location: Ct.,USA
Posts: 2,074
Received 113 Votes on 99 Posts
Most furnace controls continue to power the blower after the thermostat is satisfied since there is still usable residual heat in the furnace's heat exchanger. I would think this cool down function termination is adjustable by changing time or temperature at the control board.
 
  #3  
Old 01-07-20, 10:32 AM
J
Member
Thread Starter
Join Date: Jan 2020
Posts: 4
Received 0 Votes on 0 Posts
Hi beelzebob,
Thanks for the reply. Yes, but the blower continues to run until I remove power from the furnace. When I reapply power the blower is off until the temp drops below the setpoint.
 
  #4  
Old 01-08-20, 04:07 AM
B
Member
Join Date: Oct 2015
Location: Ct.,USA
Posts: 2,074
Received 113 Votes on 99 Posts
When you cycle power right after the thermostat is satisfied, the blower should be running until the time period has elapsed or the heat exchanger temperature is decreasing below the blower OFF setpoint depending on which design your furnace control has.
 
  #5  
Old 01-08-20, 12:53 PM
J
Member
Thread Starter
Join Date: Jan 2020
Posts: 4
Received 0 Votes on 0 Posts
The blower will run for hours blowing cold air if I don't cycle power.
 
  #6  
Old 01-08-20, 06:30 PM
B
Member
Join Date: Oct 2015
Location: Ct.,USA
Posts: 2,074
Received 113 Votes on 99 Posts
That is not what you said in post #3.
 
  #7  
Old 01-08-20, 08:43 PM
J
Member
Thread Starter
Join Date: Jan 2020
Posts: 4
Received 0 Votes on 0 Posts
Sorry for the confusion. I said in post #3, "the blower continues to run until I remove power from the furnace." I should have been more clear and said the blower continues to run after the heating is finished until I remove power from the furnace.
 
  #8  
Old 01-08-20, 08:50 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,547
Received 1,599 Votes on 1,473 Posts
Welcome to the forums.

If that is the original control board in that furnace...... then the blower is timer controlled.
If it's not shutting off..... the board has a problem.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: