Trane xr80 - tud100c948k0 - no heat, fan on - sometimes
#1
12-09-16, 05:40 AM
Join Date: Aug 2010
Location: INDIA
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Trane xr80 - tud100c948k0 - no heat, fan on - sometimes
I have xr80 - tud100c948k0. Since last few days , sometimes, at night time (only) heating switches off but blower won't stop. This remains same even after I switch off and on unit from thermostat. Then what I do is - goto basement and manually take xr80 cover off, wait for a min or so and put it back. Within few mins unit will start and heat will on. This issue won't happen consistently. So far it happened only at night time almost everyday in last 3 days. Ignitior seems good. I cleaned heat sensor using sand paper and wire brush and doesn't looks like an issue. Filter is clean too.
Not sure if this is related to relay or complete control circuit.
Any help will be appreciated.
Also where can I find replacement parts locally. Any good HVAC store chain ?
I would prefer to solve this issue asap as temperature has gone down in scotch plains, New Jersey .
Thanks in advance.
Not sure if this is related to relay or complete control circuit.
Any help will be appreciated.
Also where can I find replacement parts locally. Any good HVAC store chain ?
I would prefer to solve this issue asap as temperature has gone down in scotch plains, New Jersey .
Thanks in advance.
#2
12-09-16, 08:04 AM
Group Moderator
So far... what you are describing is an overheating problem. Make sure filter(s) are clean.
Check registers and returns.
There should be a sight glass in the blower door where you can look in and see the red trouble LED on the control board. The flashes will tell you the fault/problem.
More info on back of blower door.
Check registers and returns.
There should be a sight glass in the blower door where you can look in and see the red trouble LED on the control board. The flashes will tell you the fault/problem.
More info on back of blower door.
#3
12-09-16, 08:11 AM
Join Date: Aug 2010
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Thanks for reply. Red light is slow blink which is normal operation. Filter is clean too. Cleaned y'day one more time and still issue happened again today.
Can you let me know how to check registers please ?
Can you let me know how to check registers please ?
#5
12-09-16, 10:42 AM
Group Moderator
A slow blink is normal. It means the system is not calling for heat.
Try turning the thermostat up a few degrees.
Try turning the thermostat up a few degrees.
#6
12-10-16, 12:10 AM
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Finally , noted 4 flashes when it exactly happened.
Thanks everyone for reply. Tonight it happened again and I noted 4 flashes when it happened exactly. This time though, unit is not starting heat at all.
Fault error sheet on my furnace shows 4 flashes means "open high limit device".
It seems to me - I need to replace the high limit device . Any other thoughts ?
Fault error sheet on my furnace shows 4 flashes means "open high limit device".
It seems to me - I need to replace the high limit device . Any other thoughts ?
#7
12-10-16, 01:57 PM
Forum Topic Moderator
It is more likely that poor airflow is causing that limit to trip than you have a faulty limit.
If you also have air conditioning inspect both side of the evaporator coil
A weak run capacitor or a plugged air filter can also trip a limit.
An undersized return air intake coupled with a highly restrictive 3M air filter can trip that limit.
If you also have air conditioning inspect both side of the evaporator coil
A weak run capacitor or a plugged air filter can also trip a limit.
An undersized return air intake coupled with a highly restrictive 3M air filter can trip that limit.
