Hi Sean, Did you ever manage to fix this - I've got the same hot tub and a similar issue in the fact it runs for a few minutes with simply the filter running and then errors with the E1 error. We had quite a major flood recently which thankfully didn't quite reach the house, although elevated on decking a good foot and a half above the grass, the water got high enough for the hot tub to be sitting in just short of an inch of water. The circuit breaker was completely submerged and I've replaced that directly from mSpa but I thought the hot tub itself was initially OK. I've taken the control box apart and checked the filter and although it makes bit of a rattle (it always kinda has) it's clear of dirt. I was thinking of ordering a replacement filter but wondered if you'd had any success before I shell out £65 on a guess.