[philipk65]

Hi, I'll give a back story first. I have a 17 years old York Diamond 80 furnace. We RARELY use it so it's had an easy life (we live on coastal CA.). On Christmas we ran it for guests and it acted funny. Heated a couple of degrees shut off, blower stays on then heat fires up again. Tried the upstairs thermostat and it the furnace work fine (heat, blower worked for 15 minutes heated to right temp. shut off heat then blower shuts down in 2 minutes like it should. Maybe the thermostat downstairs is bad. put an old working thermostat on. Same issues. Maybe something in furnace. Opened up furnace to look around, now NOTHING works at all but the manual FAN setting on the upstairs and downstairs thermostats! I tried all the trouble shooting tips online to no avail. Also, the code light flashed 1 time for 1 second after the door is closed and then stays off. Any ideas?
Thanks. Kevin

Yes, dual zone and filter is new and vents open.

I have a York furnace that acts funny. The house is a dual zone (one furnace, two thermostats). The upstairs thermostat runs the furnace fine. Heats up fine, takes 5 minutes to satisfy the thermostat, heat stops then blower turns off in a minute or two.
Now, the downstairs thermostat, fires the furnace fine then heats for 3 to 8 minutes, flame/heat turns off then the blower run for 3-4 minutes. And the second the blower turns off the heat fires right back up again and does this for several cycles. There are no code flashes from the control board. What could cause this? Thanks!

 

[user_12345a]

Re: York Diamond 80 furnace issues

Is your system zoned?

Could be tripping the limit based on description - check filter and make sure all vents are open/clear.

 

[roughneck]

Re: York Diamond 80 furnace issues

Use your meter and test to see if the furnace is calling to run.

 

[user_12345a]

You have to see if the call for heat to the furnace is being dropped - power gets applied to the W terminal on the board by the zoning panel.

Could be an internal problem - ie safety opening or external.

 

[roughneck]

Is this the same issue as in your other thread?
You never responded to that one. Despite several members asking questions.

https://www.diychatroom.com/f17/york-diamond-80-furnace-issues-676663/

 

[Missouri Bound]

Replace the downstairs thermostat. If that doesn't help replace the zone control.
Trouble shooting starts by isolating different components.
The fact that the upstairs seems to be working fine would rule out the problem with the furnace.

 

[user_12345a]

It's unnecessary to replace parts to troubleshoot - check everything with a meter.

The fact that the upstairs seems to be working fine would rule out the problem with the furnace.

Not necessarily, the upstairs zone could be larger so it may pass enough airflow to prevent limit trips.

If it's running near the max of the temp rise range, it may not take much to cause overheating - a bypass damper bypassing too much air, dirty filter, blower wheel getting dirty.

Some furnaces shut the fan while warming up so it could very well be limiting out.

 

[Missouri Bound]

Not necessarily, the upstairs zone could be larger so it may pass enough airflow to prevent limit trips.

.

I am under the impression this is a new issue. But if not your suggestion can be accurate. Blocked return and supply could also create a short cycling issue.

 

[philipk65]

Yes, this is a new issue.

FYI - the upstairs is a lot smaller than the downstairs.

 

[philipk65]

Re: York Diamond 80 furnace issues

The first issue I got working, now its something new

 

[roughneck]

Ok, check with your meter for a call for heat.

 

[surferdude2]

This thread seems to be fractured from an earlier one. It may tend to cause some people to be confused but not me, I'm always pre-confused ahead of time, so not to worry. lain:

 

[Missouri Bound]

This thread seems to be fractured from an earlier one. It may tend to cause some people to be confused but not me, I'm always pre-confused ahead of time, so not to worry. lain:

For many of the years I have been on this planet I have found that starting confused is much better than getting confused.
It saves time.

 

[user_12345a]

Note to others - I did not start this thread.

The original post went missing, please fix this thread moderators.

 

[surferdude2]

Somebody's been dipping into the hard cider again. I wish they would share! :vs_OMG:

 

[joed]

threads merged