overheating

i have a 2005 down east spa by master spa. it is overheating the water. we set the temp on 80 and the mode on sleep and it got to 107. we had the thermostats checked and both read ok. we removed the cabinet insulation and the filters to see if that was the problem. after cooling down overnight, i turned power back on and set to 95 on economy mode and in two days was 103. we bought the unit new and it performed perfect until this year. any suggestions appricated. thanks in advance

[Mary]

Is the actual water temperature the same as what the readout says it is? Also, how many hours a day is the filter cycle set for and what is the ambient temperature during the day this time of year? How was the spa temperature senor tested?

mary, yes, the temp readout is correct. the temp sensors were checked by a spa repair person in the area with an ameter. the reading was .017 , he had a new one on hand and it read the same, so we deterrmened the temp sensors ok. this morning, i disconnected the terminals from the electrical panel to the heating element(no way it can heat now) i checked the temp just before this post and it was now 104. still have no filters in unit. the pump sounds smooth as it ever did. im gonna drain the water and refill with new water. we havent used the spa in ten months(wife was pregnant)and the water is 12 months old, however we have maintained proper ph and other chemical levels. thanks for your help. look forward to hearing from you soon.

[Mary]

Yes I would recommend replacing the water. Then I would take note of the water temp after fill up and leave the spa heater disconnected over night and see what the temp gets to. The reason I asked how long the filter cycles are set for and what the outside temp is during the day because if the pump is running for a long period of time and it's hot outside the spa could potentially overheat with the heater not even coming on. This is due to the cover and a well insulated spa.

Also, I do not believe this model spa has a 24 hour a day circulation pump but can you please verify that for me. This would be a seperate small pump from your regular therapy jet pump.

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.

i have replaced the water and checked the tem. it rose from 69 to 78 overnight, however the temp was set to 80, therefor the pump ran all night thinking it needed to heat water. the heater is still disconnected. the polling cylce is set 2 min ever 30 min, and it suppposed to heat water if necessary. the filter cycle is 2 hours ever 12 hours. there is no circ pump.

im having some trouble posting, so bear with me if it takes a while to reply. sometimes it wont post my message for some reason, and other times it will show up a day later.

[Mary]

I would go ahead and reconnect the heater. Leave it set to 80 or a little higher in case the water is already there and when it reaches set temp take note if the heater indicator shuts off. If so and you are comfortable using a volt meter I would then take a voltage reading going to the heater to verify that power has shut off going to the heater.

thanks, mary. i will reconnect in the morning, and test with a meter later and let you know.

mary, sorry for the delay, i have yet to chech the heater with a volt meter as i can not find mine. im gonna have to borrow one. as soon as i do, i will post a reply. thanks again.