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Category: HVAC
Satisfied Customers: 14624
Experience:  15yrs in the HVAC industry with certificates and degrees.
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I have evolution 90i heat kicks on for few minutes like 2-3

Customer Question

I have Bryant evolution 90i heat kicks on for few minutes like 2-3 after that hear bunch of clicking gas shuts off and inducer stops but blower keeps going for another minute or so all while flashing code 24 which is 24v ac open . after blower stops code 34 starts flashing only . I checked fuse and 24 volt across fuse seems like when it wants high heat its kicking off idk?
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: all good
JA: Do you plan on doing the work yourself?
Customer: yes possibly
JA: Anything else we should know to help you best?
Customer: I did have pressure switch error few weeks ago but traced back to clogged trap cleared that and its been good until now
Submitted: 8 months ago.
Category: HVAC
Expert:  HVAC Guru replied 8 months ago.

Hello, one minute while I get some information together.

Expert:  HVAC Guru replied 8 months ago.

Hello and thanks for using this service! If you are a JA Member I would like to personally thank you and welcome you back! I am HVAC Guru an extremely experienced tech on the site and I try to get to as many customers as I can. NOTE it takes time for me to type research and add links so please wait for me to respond back I can only do this so fast. Secondly, I do not know your skill level so please try and let me know if I am going beyond your knowledge or comfort zone thanks! I strive for a 5 star rating from everyone especially our JA members.


This is common on the Bryant 90i units, you need a new control board to fix that issue. Replace that and you will be good to go.

All I ask is please use the Star Rating Link at the top of your page before leaving, that is the only way I am credited through the site, tips are appreciated.

Customer: replied 8 months ago.
Hello thanks for response . This unit has 2 pressure switches high and low on low side I have 24 volts and on high I don't have 24 will it supply it when called for high heat
Customer: replied 8 months ago.
Just asking cause I had issues with switches before
Expert:  HVAC Guru replied 8 months ago.

If the pressure switch was not working it would not even glow