Pool temperature reading is wrong

PoolInMN

Member
Oct 6, 2018
21
Minneapolis
My pool temperature reading has been accurate since we've had the pool for the past two years. Last night I turned the heater on and it showed 76 degrees which seemed low but I thought might be correct and I let the heater run over night. This morning it was still reading 76 degrees both on the heater itself and the control panel. I put my hand in the water (don't have a in pool temperature gauge yet) and it felt much warmer than 76 degrees to me after having the heater run overnight. I also felt the water from the return jets and it was warm so I'm certain the heater had been running.

Is there a common component related to the temperature reading that can fail? Maybe the sensor?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,863
Northern NJ
... both on the heater itself and the control panel. ...
Where is this "control panel"?

Do you control your HP from automation or on the HP controls?

Thermistors that measure water temperature often fail. I can't tell from your post or signature what you have that controls your HP. Get a thermometer to directly measure your water temperature before you begin replacing parts.
 

PoolInMN

Member
Oct 6, 2018
21
Minneapolis
I have a "control panel" that is fairly similar to EasyTouch Control Systems. I don't use it to control the temperature though I think in theory I could and it does display the temperature. I do control the temperature directly on the heat pump itself.

I have a thermometer on order so I'll be able to test the water temperature tomorrow. It looks to me like the temperature is read by a sensor that is attached to the PVC piping between the filter and the heater. My guess is maybe that sensor has gone bad? It just seems odd since it was working well up until yesterday.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,863
Northern NJ
The temperature readout on the HP should be internal to the unit. Two independent temperature readouts would not fail at the same time. Sounds to me like your water is 76. Confirm with a thermometer.
 

Tenab

Bronze Supporter
Jun 26, 2019
162
NE Texas
My Heat Pump reads different than my Intellisense.

The pump was off the other day due to power outage. When it came back, I had to reset breakers and noticed Intellisense thought my water was 105¡ 🤣 It probably was in the PVC sitting still before I got the pump going.

The pool water was no where near that.
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,383
Stuart/FL
I'm with Allen. The automation system usually has it's own temp sensor. So does the heater. Odds of both failing are pretty remote. The gauge will help diagnose. Also, when the sensors fail they usually creep higher for a short while then go straight up.

Chris