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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22627
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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I have a totaline P274. THe 5amp fuse blew in the air

Customer Question

I have a totaline P274. THe 5amp fuse blew in the air handler. I replaced the fuse. When I turn the breaker back on, all of the segments on the display light, then it displays HP (it is a heat pump) then it displays the temp setting for about 1-2 seconds and goes back to full display. It will continue to cycle back and forth like that. I should mention that the A/C was working just fine yesterday before the 5amp fuse blew. I should also mention that we live in FL and took a pretty close lightening strike a few days ago that damaged some of our electronics.
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: Thought the A/C continued to work fine after the strike
JA: Do you plan on doing the work yourself?
Customer: Up to a point. I'm pretty handy, have multimeter, tools etc. If it goes beyond my ability, then I'll call my ac guy. If it's a thermostat, I certainly can replace that.
JA: Anything else we should know to help you best?
Customer: the house and a/c are 15 yrs old a/c is a carrier
Submitted: 1 year ago.
Category: HVAC
Expert:  BillyHvac replied 1 year ago.


My name is Billy

Unfortunately your thermostat got a static or short when the fuse blew.

Did you find what blew the fuse?

Customer: replied 1 year ago.
I replaced it. It was the little 5amp fuse on the circuit board in the air handler
Customer: replied 1 year ago.
replace the thermostat?
Expert:  BillyHvac replied 1 year ago.

I apologize there was a site glitch...we have one shot at another you still have your manual?..or need one for a test?

Customer: replied 1 year ago.
It's a two story house w/ two A/C units. Same thermostat on both. I'm going to swap them and see if the good thermostat works. If so, then I'll replace it. I downloaded the manual, but nothing helpful in it.
Expert:  BillyHvac replied 1 year ago.

If you run the install set configuration and it still faults replace thermostat.

Sometimes going back to set up will clear it.

I wish you the best