How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Gaztech Your Own Question
Gaztech, HVAC Technician
Category: HVAC
Satisfied Customers: 468
Experience:  Owner at Gaztech
Type Your HVAC Question Here...
Gaztech is online now
A new question is answered every 9 seconds

My trane XV 95 furnace has a 3 flash code and stopped

Customer Question

My trane XV 95 furnace has a 3 flash code and stopped working. I know its a pressure switch problem but could it have been caused by a dirty air filter and how do I reset it?
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: Thermostat is fine but filter was very dirty. Replaced the filter but how do I get rid of the flash code
JA: Do you plan on doing the work yourself?
Customer: Yes
JA: Anything else we should know to help you best?
Customer: no
Submitted: 10 months ago.
Category: HVAC
Expert:  Gaztech replied 10 months ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue.

If my initial response doesn’t answer your question then let me know and we can continue our conversation.

NOTE: I can only get paid for assisting you if you RATE ANSWER the 5 star rating after you are satisfied with answer.

Are you ready?

Expert:  Gaztech replied 10 months ago.

Not a filter issue.

If this is the first time this year that your furnace has got the call for heat. It might be something as simple as a restriction in the air tubing going from the inducer motor housing to the pressure switch, something as small as a spider or a spider egg. If there is a restriction the pressure switch will not make. If that switch does not make it will not allow the ignition process to occur. There could also be a restriction in the flu. Some furnaces this will be PVC. If there was a dead bird, a nest, or anything blocking the flu. That pressure switch will not make. The pressure switch is a safety in place to prevent your furnace from firing up. Turn off power to your furnace and if you are capable of removing the upper panel on the front of your furnace. Look for a rubber tube a little bigger than a straw. It will be hooked to a round plastic switch, a little smaller than a can of chew. Unhook the vent tube and blow through it and put it back on. Then remove the exhaust from the top of the furnace. Now turn the power back on. If it fires up immediately turn the furnace off and put the exhaust back on. Then turn the power back on. If it doesn't start your flu is restricted.

Customer: replied 10 months ago.
Okay , I will try that. Unfortunately its in a rental house and can not do it until tomorrow
Expert:  Gaztech replied 10 months ago.

Hope this will get you going, I am punching out for tonight

Best regards


Expert:  Gaztech replied 10 months ago.

I can only get paid for assisting you if you RATE ANSWER the 5 star rating

Best regards


Expert:  Gaztech replied 8 months ago.

At this point the negative pressure will need to be measured with a manometer to determine if it is out of specs,

the pressure switch may be defective and not sensitive enough to close.

You could try replacing pressure switch or have a technician take readings of negative pressure.

Sorry you are having trouble getting it going but after all the checks we covered, it should work, unless that we are dealing with a defective pressure switch, it may be a indication of a more serious problem such as a cracked heat exchanger ...