abc123 Posted July 27, 2012 Report Share Posted July 27, 2012 I had been noticing this month that the control panel is getting a little harder to use, normally I go out and push the button for ten mins and let it run so I can test my water. Lately I have been having to press either of the buttons a few times before they respond. Four days ago I went out and my water was almost warm, I left it alone after unplugging the power, and searched Google for Classic F Jets work but no heat. I ran into something about the circulation pump, and I had forgotten to see if the water was circulating. I went out yesterday plugged it back in and saw the water circulating. Left it plugged in this time. Today I found something about the Hi-Limit Thermistor, so I went out to find it and see if I could see anything that looks odd about it so I might know if its having a problem. I noticed a white crust on the outside of one of the Thermistor, So I took a picture of it. I am not sure what one is what so the one with the white crust on it is the one at the far end. I also noticed that the plugs on the other end of the wire are very loose and floppy. Heater going bad or Thermistor going bad? After I took the photo I decided to feel the water and it is warm again. Did I reset something by unplugging ? Also this link has a photo of the other side of the wires, I see bare covered wires on one of the plugs does this need to be addressed? http://img.photobucket.com/albums/v198/itsmeab4u/Hot%20Tub/IMG_20120727_144750.jpg Quote Link to comment Share on other sites More sharing options...
PreservedSwine Posted July 27, 2012 Report Share Posted July 27, 2012 If the high limit thermistor was bad- your power LED would flash on the control panel, and the jets would not work. The control thermistor, however, can go bad, and the jets will still work. The white stuff is hardness, it shouldn't be there- it means you have a very small leak, and the water evaporates before you notice it dripping. The white stuff it whats left after the water has evaporated. You don't need a heater, just a new thermistor O-ring, or possibly a new heater-body, if the old one has cracked along the seam that runs the length of the heater body- across both thermistor threads. As far as it heating now, yes, plugging in and unplugging in a thermistor will sometimes fix a faulty thermistor reading due to tiny amounts of corrosion at the harness, which is broken up by unplugging, and then plugging them back in. That era spa (1995 - 1996) uses a flow switch as well, so be sure your filters are clean. Do you hear excessive clicking? Do you hear a clear, single "click" at some point when turning the temp all the way down, and then another click (at roughly the same spot on the temp dial) when turning the temp back up? Quote Link to comment Share on other sites More sharing options...
abc123 Posted July 27, 2012 Author Report Share Posted July 27, 2012 Thanks for getting back to me so fast ! I hear no clicking and the body of my heater seems ok, I did happen to try and check that since I read about one splitting at the seam. I will however go check that better after wiping it off so I can see under there. My LED is not flashing. Now do I have to find an O-Ring for this heater, or can I run to home depot and get one? I see one online for this heater for .68 Quote Link to comment Share on other sites More sharing options...
abc123 Posted August 3, 2012 Author Report Share Posted August 3, 2012 You don't need a heater, just a new thermistor O-ring, or possibly a new heater-body, if the old one has cracked along the seam that runs the length of the heater body- across both thermistor threads. I got my O-Ring yesterday. $1 with shipping! Now would I want to remove the heater from the hot tub to change it? I guess the removal of the thermistor will give the water an escape route. I read that you can use a cork to close up the hose for minimal water loss. I ordered both O-Rings thinking that the other is the same age. Should I go ahead and change them both, or wait for a leak. Any tips on how to go about this? The chemicals are perfect now, with the help of this website! I am probably close to empty and refill time if that would be best. Quote Link to comment Share on other sites More sharing options...
PreservedSwine Posted August 3, 2012 Report Share Posted August 3, 2012 I wouldn't use a cork. Either do it next time you drain the spa, or, just be very, very quick with the O-ring swap. Do NOT overtighten the thermistor when you put it in- the plastic housing is at least 16 years old, and separates along the seam easily when tightening the thermistors securely in place. In fact, I would drain it, and use a little silicone when replacing the O-Rings, to ensure if there is a small crack- the silicone will seal it. Quote Link to comment Share on other sites More sharing options...
abc123 Posted August 4, 2012 Author Report Share Posted August 4, 2012 Thank you much! I will take your advice, be slow and careful instead of fast. Thanks for all your help, its appreciated Quote Link to comment Share on other sites More sharing options...
Roe Posted April 19, 2018 Report Share Posted April 19, 2018 On 7/27/2012 at 4:38 PM, PreservedSwine said: If the high limit thermistor was bad- your power LED would flash on the control panel, and the jets would not work. The control thermistor, however, can go bad, and the jets will still work. The white stuff is hardness, it shouldn't be there- it means you have a very small leak, and the water evaporates before you notice it dripping. The white stuff it whats left after the water has evaporated. You don't need a heater, just a new thermistor O-ring, or possibly a new heater-body, if the old one has cracked along the seam that runs the length of the heater body- across both thermistor threads. As far as it heating now, yes, plugging in and unplugging in a thermistor will sometimes fix a faulty thermistor reading due to tiny amounts of corrosion at the harness, which is broken up by unplugging, and then plugging them back in. That era spa (1995 - 1996) uses a flow switch as well, so be sure your filters are clean. Do you hear excessive clicking? Do you hear a clear, single "click" at some point when turning the temp all the way down, and then another click (at roughly the same spot on the temp dial) when turning the temp back up? What does the single click mean when turning up the temp and at the same point of turning it down? I am also having a problem with the circulation pump. Quote Link to comment Share on other sites More sharing options...
PreservedSwine Posted April 30, 2018 Report Share Posted April 30, 2018 On 4/18/2018 at 9:23 PM, Roe said: What does the single click mean when turning up the temp and at the same point of turning it down? I am also having a problem with the circulation pump. A single click is what you want to hear. No click would mean either a bad thermistor, or bad heater relay. If it's a 95 or 96, you need good circ pump flow to close the flow switch. Good luck! Quote Link to comment Share on other sites More sharing options...
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