Welcome to our forum.
After Hurricane Rita the control panel was filled with sand. The repairman came out and fixed it. No charge! I was amazed and very appreciative.Bill
2005 Vanguard: - Cover pools water, don't know if this is an issue. no response from HS.
If you can, you should open the zipper and flip over the foam board. While you have it out, check for cracks, and also look over the vapor barrier to see if you have any failures in that. If so, close them up with heavy packing tape.
Oh, BTW...stuck heater relay...changed out whole control board. Been fine since.
How hot did your water get with the stuck relay?