I have a hamilton 780. The temp of water in our spa is inconsistent and we are experiencing very cold below freezing temps. I have tarped and setup external heat in an attempt to keep the spa from freezing.
Yesterday evening I went out to test the water temp of the spa. I found that the water level was low. I topped up the water to go over the filer barrier. The – – – symbol was on. I shut off the breaker and then put it on again. All the jets went on. I tested the water temp with a water thermometer because built in temp gauge has not been working properly for about four months. Temp was 85F. After two hours the water was lukewarm. The O N symbol was showing. I covered tub with tarps to maintain heat yesterday evening. This morning I checked under the tarp and air temp was 3 C. Checked again at lunch and water was lukewarm and the symbol was – – – After work water was hot and symbol was – – – I have now enclosed hot tub area with tarps so I can work with problem.
What do you advise?