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Ask Rick or Nick in Texas Your Own Question
Rick or Nick in Texas
Rick or Nick in Texas, HVAC Technician, Manager, Owner
Category: HVAC
Satisfied Customers: 92
Experience:  25yrs State Licensed/ own/ operate/ repair/ install/ design-> AC & Heating company in Texas
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limit switch open what does that mean and how can i fix it

Customer Question

limit switch open what does that mean and how can i fix it
Submitted: 8 years ago.
Category: HVAC
Expert:  Rick or Nick in Texas replied 8 years ago.


There usually two limit switches located at either end of you burners. The have a football shaped metal mount with a black round plastic assembly on it with a red or blue button in the center and has two wires connected to it and run from one to the other on one side. Locate these limits and push in the button to reset them. They will click slightly when reset. If one or both reset retry the call for heat and at a safe distance try and observe the lighting sequence and see if it starts. Let me know if this helps. If not i will need the make and model # XXXXX your unit.

Expert:  Jim Eastwood replied 8 years ago.
Wolvie 1974 since you did not accept the above answer I will give it a shot. You asked what does it mean if a limit is open. Almost always it means that temperatures in some part of your furnace have exceeded normal levels also it means is that in the case of a manual reset limit as Rick described the burner flame or hot gases are coming out of the front of the furnace in this case you should have a professional take a look at your furnace as you likely have a serious problem. Other limits typically automatic reset are often located just above the burners these normally stick open when there is an airflow issue dirty filter, dirty coil or blower motor not working. If this answers your question please hit accept.
Expert:  Rick or Nick in Texas replied 8 years ago.
Jim thx but I got this.....I am waiting for Wolvies's response as to go thru the process as he observed to see if it was just an isolated incident or if there are signs of a more serious problem BEFORE he spent alot of money on a service call I/we might be able to help discover and save him some money which is our objective to help, inform and save our customers money whenever possible not just jump on and give a general answer and ask for an Accept. I for one do not expect one UNTIL I have not only answered a question but hopefully solve the problem and save our customers money.....woohoo!