Well i refilled my tub today. The temp was 1C but felt like -4C with the wind chill. The water was 10C from the house so hopefully no lines got damaged. It is slowly heating 5C every 2 hrs so will probably take about 11 hrs to heat to 37.5C overnight. One thing i forgot to do is turn the power off at the breaker when draining and refilling. I put the jets in off mode and they kicked back on when the water line was still below the jets. Would this cause any damage to the pump? The jets are still working but wondering if damage can occur as i turn the jets and air on for 10 secs to make sure all the biofilm and water is out of the lines. I also filled the tub halfway and drained before i fill it again to make sure all the ahhsome cleaner was out of the tub.