Orie Posted February 2, 2009 Report Share Posted February 2, 2009 Hello all, first time owner of a spa (i don't fit in normal tubs!) and first post here. Just finished setting up a 1992 Sundance "Marin 32", also known as a "600 series" i believe. My problem is this.. on first heat up, the spa heated to about 96deg, then refused to get hotter. The heat light simply clicks off, and it appears that the computer doesn't think it should be heating the water anymore. If i put a hose directly on top of the temperature sensor in the filter area and blast cold hose water at it, the heater light comes on, the relay clicks in the control panel and it seems that the heater comes on, judging from amperage draw. I got the tub up to 104 once using this method and enjoyed about 1 hour in the tub. Since then (overnight), it seems to want to come on at about 86deg, and the hose trick doesn't work so well anymore. I'm betting this is the temperature sensor, but at $60 a pop, I'd appreciate any other advice. The "Flow" light is on, and all mode selects work, including manual pump low/high. I'm running the tub at 240vac. Thanks all! Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted February 3, 2009 Report Share Posted February 3, 2009 My Sundance comes on at 80, Yours comes on at 86. Might be a calibration thing, but I don't even know if it can be calibrated. You may have to get one. Anyone jump in here. Quote Link to comment Share on other sites More sharing options...
ps558 Posted February 4, 2009 Report Share Posted February 4, 2009 Hello all, first time owner of a spa (i don't fit in normal tubs!) and first post here. Just finished setting up a 1992 Sundance "Marin 32", also known as a "600 series" i believe. My problem is this.. on first heat up, the spa heated to about 96deg, then refused to get hotter. The heat light simply clicks off, and it appears that the computer doesn't think it should be heating the water anymore. If i put a hose directly on top of the temperature sensor in the filter area and blast cold hose water at it, the heater light comes on, the relay clicks in the control panel and it seems that the heater comes on, judging from amperage draw. I got the tub up to 104 once using this method and enjoyed about 1 hour in the tub. Since then (overnight), it seems to want to come on at about 86deg, and the hose trick doesn't work so well anymore. I'm betting this is the temperature sensor, but at $60 a pop, I'd appreciate any other advice. The "Flow" light is on, and all mode selects work, including manual pump low/high. I'm running the tub at 240vac. Thanks all! Temp sensor needs replaced Quote Link to comment Share on other sites More sharing options...
Orie Posted February 4, 2009 Author Report Share Posted February 4, 2009 Temp sensor needs replaced Ordered one yesterday, we'll see what it does on friday! Quote Link to comment Share on other sites More sharing options...
ps558 Posted February 5, 2009 Report Share Posted February 5, 2009 Temp sensor needs replaced Ordered one yesterday, we'll see what it does on friday! Before you go thru the hassle of replacing the unit. Plug it in were it goes and just drape it over the side of the tub into the water for a quick test. Quote Link to comment Share on other sites More sharing options...
Orie Posted February 11, 2009 Author Report Share Posted February 11, 2009 Hello all, first time owner of a spa (i don't fit in normal tubs!) and first post here. Just finished setting up a 1992 Sundance "Marin 32", also known as a "600 series" i believe. My problem is this.. on first heat up, the spa heated to about 96deg, then refused to get hotter. The heat light simply clicks off, and it appears that the computer doesn't think it should be heating the water anymore. If i put a hose directly on top of the temperature sensor in the filter area and blast cold hose water at it, the heater light comes on, the relay clicks in the control panel and it seems that the heater comes on, judging from amperage draw. I got the tub up to 104 once using this method and enjoyed about 1 hour in the tub. Since then (overnight), it seems to want to come on at about 86deg, and the hose trick doesn't work so well anymore. I'm betting this is the temperature sensor, but at $60 a pop, I'd appreciate any other advice. The "Flow" light is on, and all mode selects work, including manual pump low/high. I'm running the tub at 240vac. Thanks all! Bought a new temp sensor and installed it over the weekend. The tub now heats all the way up to 104 and holds there! Problem solved. Installation was a piece of cake, though it will require draining the tub below the sensor level in the filter area, or a really quick hand! Quote Link to comment Share on other sites More sharing options...
Pool Guru Posted February 11, 2009 Report Share Posted February 11, 2009 Just as a little postscript, the question of calibration was mentioned earlier in this thread. As a general FYI to anyone following this post, most mechanical thermostats do have a calibration screw. There have been many times over years when I have had to go in and replace a thermostat that another tech had recalibrated. Recalibration (setting the old T-stat to heat to a higher temp) is never a good idea because what you gain in range you lose in accuracy. It is very likely that you could end up with an overheat situation, especially if the high-limit is also failing (since the thermostat and the high-limit can both work in a similar manner, and they are likely the same age). The cause of the lower temp on the thermostat is usually either corrosion or an eventual breakdown of the expansion gases used inside the thermostat. As demonstrated here, it is usually relatively cheap and fairly easy to replace. John Quote Link to comment Share on other sites More sharing options...
Orie Posted February 12, 2009 Author Report Share Posted February 12, 2009 Just as a little postscript, the question of calibration was mentioned earlier in this thread. As a general FYI to anyone following this post, most mechanical thermostats do have a calibration screw. There have been many times over years when I have had to go in and replace a thermostat that another tech had recalibrated. Recalibration (setting the old T-stat to heat to a higher temp) is never a good idea because what you gain in range you lose in accuracy. It is very likely that you could end up with an overheat situation, especially if the high-limit is also failing (since the thermostat and the high-limit can both work in a similar manner, and they are likely the same age). The cause of the lower temp on the thermostat is usually either corrosion or an eventual breakdown of the expansion gases used inside the thermostat. As demonstrated here, it is usually relatively cheap and fairly easy to replace. John Well said. I couldn't agree more, probably the best $60 i've spent on the tub, it works like new now, and the dial is very precise now. My friends tub suffered several overheats due to "recalibration", where the water was almost scalding hot. I'd rather know that the temperature control will be reliable. Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted February 13, 2009 Report Share Posted February 13, 2009 The calibration I was referring to was a software calibration not a mechanical one. These temp sensors never touch water and are in a plastic "well". Old school "bulb tstats" should never be calibrated unless its Friday afternoon (huh) Quote Link to comment Share on other sites More sharing options...
Pool Guru Posted February 13, 2009 Report Share Posted February 13, 2009 The calibration I was referring to was a software calibration not a mechanical one. These temp sensors never touch water and are in a plastic "well". Old school "bulb tstats" should never be calibrated unless its Friday afternoon (huh) Well, old school "bulb tstats" also never touch water unless, of course, the thermowell has corroded away. Which, by the way, would explain the whole problem in the first place. As to a software recalibration...nope. Not possible. John Quote Link to comment Share on other sites More sharing options...
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