Temperature Sensor Question...

[nitromax]

Hello,

I have a Hot Springs, Hot Spot, Trinidad, 2005 model hot tub. I just replaced the jet pump on it as it was rusted out. The pump works perfectly now on both speeds, the lights work, and the heater is jamming out at 111 degrees, even though the default 102 is what it should be stopping at. I replaced the filter as well. The problem is the display will read like 85 degrees but in measuring the water with an outside probe it reads 111 degrees, and I get 3 blinking lights on the display panel. The heater is obviously working, so I thought maybe it was a faulty temp sensor. The part number is here: http://www.backyardplus.com/proddetail.php?prod=71578

I tested the water at 106 degrees and the resistance on the temp sensor was 5.4K, at 105 degrees it was 5.6K and at 104 degrees it was 5.8K. I have a couple of different charts that shows what the temp/resistance values should be. That is close to a 10K thermistor chart, but how far or close off will show that the sensor is bad? From the chart they should only be about 100 ohms different for each degree. From a price stand point I was hoping it was a bad sensor. Any ideas on what this problem is please?

Thanks in advance if you can help!

[Tman122]

Hello,

I have a Hot Springs, Hot Spot, Trinidad, 2005 model hot tub. I just replaced the jet pump on it as it was rusted out. The pump works perfectly now on both speeds, the lights work, and the heater is jamming out at 111 degrees, even though the default 102 is what it should be stopping at. I replaced the filter as well. The problem is the display will read like 85 degrees but in measuring the water with an outside probe it reads 111 degrees, and I get 3 blinking lights on the display panel. The heater is obviously working, so I thought maybe it was a faulty temp sensor. The part number is here: http://www.backyardplus.com/proddetail.php?prod=71578

I tested the water at 106 degrees and the resistance on the temp sensor was 5.4K, at 105 degrees it was 5.6K and at 104 degrees it was 5.8K. I have a couple of different charts that shows what the temp/resistance values should be. That is close to a 10K thermistor chart, but how far or close off will show that the sensor is bad? From the chart they should only be about 100 ohms different for each degree. From a price stand point I was hoping it was a bad sensor. Any ideas on what this problem is please?

Thanks in advance if you can help!

I think you got it. The sensor is also the logical place to start. 12 years is pretty good longevity on all those parts. If the tub is still doing it for you then........(in good shape and comfortable)

I say all the parts would be a good investment for the next 12 years of longevity. If you have the skill and time. And it sounds like you have the skill. If the tub performs for another 5-8 years your doing good. New tubs are 8 grand. Don't spend more than 2 grand and your fine. Unless you want new. And you can spend 5-6 grand for a pretty decent new tub almost like what you got. Shouldn't be to hard to replace that sensor.