Hi all, newbie here. First let me say that this forum is full of awesome info, but I can't find the answer to my issue after some extensive searching.

Issue: Summit heat pump first up no problem and kicks out beautiful warm water for about a minute before switching to "F5" which is defrost mode. It doesn't switch out of defrost mode unless I flip the breaker off and on again, but it still flicks to defrost mode after 1 minute.

I've read the manual and searched online for answers and it could be a coil sensor that is shot ($30 part) or the board ($600 part). I found a thread here that talked about backwashing the sand filter, which I've done to no avail.

Here is the heat pump we have: ard-pool.ca/prd/In-Ground-Pool-Heat-Pumps-Summit-Heat-Pump_10201_10551_30018_-1_14004__I.htm/pressure.htm