Posted by
Message
pwejr88
LSU Fan
Friend of Bill
Member since Apr 2007
27998 posts

A/c issue after lightning strike. Any help appreciated
Two units. One upstairs, one downstairs.
Both Nest thermostats. Love them. No problems.


Lightning last night hits our house or right by it. Trips four breakers in the breaker box. All downstairs was ok, but it tripped three breakers in upstairs bedroom and one in bathroom. Both cable boxes and modem are off completely, I’m guessing fried. (This is an easy fix).

My problem:
The downstairs a/c is fine.
My upstairs a/c will not come on. The thermostat is reading that no power is coming in to the thermostat. The a/c breakers were never tripped.

Any advice?
This post was edited on 3/15 at 11:55 pm


rsbd
LSU Fan
banks of the Mississippi
Member since Jan 2007
12156 posts

re: A/c issue after lightning strike. Any help appreciated
Compressor is grounded out


pwejr88
LSU Fan
Friend of Bill
Member since Apr 2007
27998 posts

re: A/c issue after lightning strike. Any help appreciated
Can I fix that?
How?


Replies (0)
Replies (0)
00
brew400
LSU Fan
West side Best side
Member since Sep 2009
488 posts

re: A/c issue after lightning strike. Any help appreciated
if no power is coming into the thermostat that power typically comes from the furnace inside, if its an electrical furnace there is usually another breaker on the furnace itself. if thats ok, it could be the transformer inside of the furnace, its a simple 120-24v thats not super hard to change. if all of that checks out then call someone.


cajuncarguy
On the road...Again!
Member since Jun 2013
1854 posts

re: A/c issue after lightning strike. Any help appreciated
Call your insurance company and keep good records.


Walkerdog14
LSU Fan
Member since Dec 2014
478 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
Had to replace my outside unit last year because of this


Replies (0)
Replies (0)
10
mdomingue
LSU Fan
Lafayette, LA
Member since Nov 2010
8807 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
You should have a breaker or fuse box near your compressor. Check that. There is also likely a control board inside the furnace if you have a gas furnace, I'd assume something similar if you have a heat pump or electric heating. That may have a fuse(s) or even a breaker type trip and is probably the source of your thermostat power.

All of this from memory but the long and short is check near your outside unit for a fuse and/or breaker box. Check your inside unit for fuse/switch and that the controller unit isn't fried.

ETA if you have a reasonable price AC guy you use that you trust not to screw you, call them if uncertain. If you're in the Lafy area I can recommend the guy I call when I can't or don't have time to do it myself.
This post was edited on 3/16 at 7:08 am


Replies (0)
Replies (0)
30
Tridentds
Texas A&M Fan
Sugar Land
Member since Aug 2011
10303 posts

re: A/c issue after lightning strike. Any help appreciated
Breakers protect the wiring and not the unit. Better check that outside unit for damage.


Replies (0)
Replies (0)
10
Riolobo
LSU Fan
On the lake
Member since Mar 2017
1006 posts

re: A/c issue after lightning strike. Any help appreciated
If lightning strike use it as a cheap way to get a new unit through insurance


Replies (0)
Replies (0)
40
wickowick
LSU Fan
Head of Island
Member since Dec 2006
39615 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
Lightning damage, call insurance and HvAC guy. Things that normally have issues, garage door openers, low voltage home phones, sometimes fridges and stoves. Every home is different and sometimes it takes a little time to determine what all was damages


Replies (0)
Replies (0)
30
GATORGAR247
Member since Aug 2017
576 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
Try flipping the breaker off then back on. Sometimes they dont look tripped but are.


Replies (0)
Replies (0)
10
plazadweller
Auburn Fan
South Georgia
Member since Jul 2011
8450 posts

re: A/c issue after lightning strike. Any help appreciated
Our 6 ton package unit was fried from a power surge coming into the office. It was a 40+ year old unit and worked like a champ prior to hurricane Michael. It fried every major component on the unit. Nothing else at the office was affected including a 10 ton package unit that is15 years old.. Our HVAC tech had as much of an explanation as we did. File a claim. If possible have your HVAC tech meet at the same time as the insurance adjuster. He can go over everything with the insurance adjuster. I’m sure they’ll want to send out a “specialist” to look at it as well.


Replies (0)
Replies (0)
00
MSWebfoot
LSU Fan
Hernando
Member since Oct 2011
3183 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
I have had this before. It turned out to be the control board on the furnace. You probably want to check for fuses and the transformer as well.
You may want to check your deductable before calling the ins co. I replaced my own ac board, and garage door opener for way less than my $1k deductable.


Replies (0)
Replies (0)
10
TBoy
Notre Dame Fan
Kalamazoo
Member since Dec 2007
11399 posts

re: A/c issue after lightning strike. Any help appreciated
I had lightning fry a control panel upstairs. Although I do most small jobs myself, an A/C guy was needed to diagnose and fix it. Good luck.


Replies (0)
Replies (0)
00
Jvalhenson
Member since Sep 2017
136 posts

re: A/c issue after lightning strike. Any help appreciated
May have popped the low voltage fuse on the inside unit. There will be a 3 or 5 amp fuse that the low voltage running from thermostat to unit to control is going through. Any little surge will pop them. Check that fuse out


pwejr88
LSU Fan
Friend of Bill
Member since Apr 2007
27998 posts

re: A/c issue after lightning strike. Any help appreciated
Is that on the unit in the attic?


Replies (0)
Replies (0)
00
fallguy_1978
LSU Fan
Half mile from St George
Member since Feb 2018
13308 posts
 Online 

re: A/c issue after lightning strike. Any help appreciated
quote:

Call your insurance company and keep good records

Yep. shite happened to me last year. It fried all kind of crap in our house. Ended up costing like 3-4k


Replies (0)
Replies (0)
00
cdaniel76
New Orleans Saints Fan
Mandeville, LA
Member since Feb 2008
18791 posts

re: A/c issue after lightning strike. Any help appreciated
quote:

May have popped the low voltage fuse on the inside unit.


I've had that happen before also. It will be located on a small circuit board, usually within or mounted onto the blower motor housing.


pwejr88
LSU Fan
Friend of Bill
Member since Apr 2007
27998 posts

re: A/c issue after lightning strike. Any help appreciated
Found the fuse inside the unit on the circuit board and it wasn’t tripped either.
Guess it’s the circuit board or the transformer.
This post was edited on 3/16 at 7:20 pm


Replies (0)
Replies (0)
00
Miketheseventh
LSU Fan
Member since Dec 2017
963 posts

re: A/c issue after lightning strike. Any help appreciated
This sounds like the most logical answer. It doesn’t take much of a voltage spike to fry those control transformers


first pageprev pagePage 1 of 2next pagelast page

Back to top

logoFollow TigerDroppings for LSU Football News
Follow us on Twitter, Facebook and Instagram to get the latest updates on LSU Football and Recruiting.

FacebookTwitterInstagram