 | | | Open Temperature Limit Circuit how to fix
Asked Feb 17, 2010, 10:10 AM
—
7 Answers I have a Trane XR90 that was showing a solid diagnostic light. Could wiggle the wires and the furnace would work for a few hours. Solid light wiggle the wires and board = heat. Finally wiggling wouldn't work. So I replaced the IFC board. Went to turn every thing on and now 4 blinks on the light for a Open Temp Limit Circuit... Burners light and heat up for a minute, but the fan doesn't kick in. So,did the manual reset 2 x in 30 secs, no avail. Tried to reset the limit switch, but there is no "positive" clicking feeling, it moves but not sure it is right. Anything I am missing?
Thank you
Thread Summary |
7 Answers
 | Ultra Member | |
Feb 17, 2010, 10:25 AM
| | | If you reset the rollout protection switch and it worked for a while and now it will not work when you reset it makes me think that there is something wrong with the switch. So try again to start the furnace but this time use a jumper wire across the switch that you were working with. If that does not work there are other linit switches so try jumpering across those also one at a time.
Let me know what happens. | | | | New Member | |
Feb 17, 2010, 10:40 AM
| | | Quote:
Originally Posted by letmetellu  If you reset the rollout protection switch and it worked for a while and now it will not work when you reset it makes me think that there is something wrong with the switch. So try again to start the furnace but this time use a jumper wire across the switch that you were working with. If that does not work there are other linit switches so try jumpering across those also one at a time.
Let me know what happens. | Thank you for the quick response. Just jumped the switch and no luck. Ignition worked, blower was blowing, tubes filled then back to the 4 blink light. What is the part under the burner box w/ 2 yellow wires attached? Looked to be a sensor? | | | | New Member | |
Feb 17, 2010, 11:08 AM
| | | Quote:
Originally Posted by Tman7808 thank you for the quick response. Just jumped the switch and no luck. Ignition worked, blower was blowing, tubes filled then back to the 4 blink light. What is the part under the burner box w/ 2 yellow wires attached? Looked to be a sensor? | Update: so I jumped the switch under the burner box, and now I keep getting the quick blink LED, blower keeps running, but no fan. And it didn't kick off... | | | | Ultra Member | |
Feb 17, 2010, 12:22 PM
| | | Would you please do another list of just what your problem is at this time. | | | | New Member | |
Feb 17, 2010, 01:00 PM
| | | Quote:
Originally Posted by letmetellu Would you please do another list of just what your problem is at this time. | Now when I jumped the limit switch the blower keeps running (10 minutes) & the fire is lit, but the fan to circulate the air never kicks on. LED is fast blink (calling for heat) | | |  | Plumbing Expert | |
Feb 17, 2010, 04:36 PM
| | | Okay, so the draft inducer is running, burners ignite, but the main blower never comes on? If the main blower never comes on, the high limit is tripping(most likely not a resetable one, the resetable one is an auxilary limit, or flame rollout). Your problem is that the main blower isn't coming on. Check wiring of new board. Check for voltage going to main blower motor. | | | | Ultra Member | |
Feb 17, 2010, 05:51 PM
| | | If your fire is burning and the blower does not come on means that it is not a limit switch that is causeing the motor not to run. So use a volt meterr between the H terminal ( black wire)and the L 2 (white) terminal, do this after the burner has been burning for a couple of minutes giving the limit switch time to turn the fan on. | | |
| Thread Tools | Search this Thread | | | | Add your answer here.
Check out some similar questions!
Limit circuit open [ 2 Answers ]
I have a nordyn furnace. I replace the inducer motor cause it was making a noise and would not run all the time. I also replace a limit switch that is built onto the inducer motor. This limit switch keeps triping and it throws a code of "limit circuit open or external load on "w"." I can...
Troubleshooting 4 flashing lights - open high temperature limit switch [ 7 Answers ]
Thanks for your input. I finally was able to reverse the wiring and got it squared away. While I was in the attic I thought I would replace the motor which drives the fly wheel. I thought I was a hero till I put everything together and discover 4 flashing lights. The lights indicate "open high...
Limit circuit open [ 1 Answers ]
I have an intertherm gas furnace with a limit circuit open alarm. What can I do/check to clear this alarm?
Trane xe 80 open high temperature limit switch [ 1 Answers ]
Furnace is about 13 years old...we just replaced the ignighter in it last night because it was running through all the steps to run except ignighting. It fired right up and ran for about 7-8 hours.....now it won't ignite at all (it is running through all the steps it needs to except for...
Furnace "burner limit circuit open", How to fix? [ 2 Answers ]
The furnace in my vacant rental property does not light. The blower runs but the igniter never glows and the gas valve does not open. The LED blinks once which means the burner limit circuit is open.
How do I replace the burner limit circuit?
Inside the furnace cover I found the electronic...
View more Heating & Air Conditioning questions Search
|
