If it is 4 years old , check your warranty . We replaced the board on the Friedrich 1 ton unit we installed last spring . The Friedrich has a 5 year warranty .
We had a snow storm about the time the board went out . May have had lightning ? Many people lost power . Ours did not go out , in the night , long enough to disrupt my digital alarm clock . But we could have had surges and spikes .
The schematic shows a surge suppressor built in to the outdoor unit . Thinking about a whole house surge suppressor .
Square D by Schneider Electric Panel Mounted Single Phase Type 1 Surge Protective Device-SDSA1175 - The Home Depot
Any one have any comments on this one ? Would be easy for me to install .
Johnstone warranted our bad board .
Thank you Lord ! :-)
And thank you , Johnstone .
God bless
Wyr