I have a 2005 marquis spa (Quest). It sat idle and empty for 2 years. Today I cleaned it up and replaced the filters. The problem is the water will not heat up, also the heat led is not lit. I followed the start up procedure, set all my settings and 8 hrs. later the water was still cold.
The other strange thing is no diagnostic code. Could it be the heat sensor or heating element or both? Is it a do it yourself project?