i replaced the water tonight. the temp was 68, and verified with another thermometer. the heater is still disconnected. this model can have an optional circ pump, but mine does not. the filter cycle is still the factory setting as far as i know. the spa does a temp polling every 30 min for 2 min and only heats water if needed(supposedly). the filter cycle is also factory set for 2 hours every 12 hours. we are in northern ky, and its been boiling hot as usual, however the spa performed perfect previous summers. we would actually turn it down below body temp in summer for a more relaxing soak, and it would maintain the lower temp. for this reason i dont think my problem is weather related. if weather and outside temp is the problem, it will fix itself in a couple months and save me a bundle. if youd like to check out the owners manuel,search master spas owners manuels, i have a 2005 downeast portsmouth model with 2 pumps. thanks again for you time and reply if you need more info or have another suggestion.