Pentair temperature calibration / weird pool + hot tub reaction

[adrian_c]

Bit of a weird one today.

I have a Pentair Mastertemp 400 heater, and the Intellitouch wired remote (#520396) connected to the Intellitouch i9+3.

The heater is showing temperature 20 degrees higher than the wired remote, for both pool and hot tub. After measuring the temperature in the pool, I determined the heater is fine and the remote needs calibrating. I attempted to calibrate the water temperature on the remote, in the menu/setup/advanced/calibrate function. Seemed easy enough.

After calibration, the hot tub started to drain, aggressively. This has never happened before. I stopped the water loss by "timing out" my intellitouch i9. I then re-filled the hot tub with two hoses and repositioning my pool cover pump underwater in the pool pumping into my hot tub. After re-filling, I switched the Intellitouch i9 back to "auto" which restarted the pool filter/pump, and the hot tub draining started again. This time, I turned everything off at the breaker, and the draining stopped. When I turned the breaker back on, the Intellitouch i9 started the pool filter/pump again, and the hot tub didn't drain this time.

It's now all good, back to normal.

Is there any explanation for why the calibration would have caused the hot tub to drain, or send the Intellitouch into a drain cycle? I would like to calibrate the remote properly (I put the remote temp back to where it was ... still 20 degrees off ... to try to get the system back on even keel). Is calibrating the water temp on the remote connected to anything that would drive hot tub drainage? Seems really weird. The remote is measuring the air temperature accurately, just not the water.

Any thoughts welcome.

 

[mknauss]

Welcome to the forum. @ogdento has intelliTouch experience.

 

[ogdento]

I don't know how the intellitouch uses the water temp to control the spa or heater (I don't have either), but I have seen the temp readings get out of whack when there's not a good connection on the terminal block, usually from corrosion on the pins or the block. I suppose the sensor itself could maybe have some scaling or could be going bad, but try this first...

pull off the block, inspect the pins and the block and try cleaning the pins with very fine sand paper or steel wool and see if that changes anything. For a sanity check, if you connect a 10k resistor where the water temp sensor goes, you should get a water temp of around 76. Keep in mind that if you pull the sensors off with the system running, the pool will think it's below freezing and go into freeze mode

 

[adrian_c]

Thanks OG.
The air temperature is being read accurately, just the water temp is too low on the wired remote from the intellitouch. I will clean the water sensor as recommended. I will leave the air sensor alone as seems to be fine - that's the one that detects freezing I thought?

 

[ogdento]

Yeah the air sensor is for freeze... When I test boards I use a mocked up connector block that's just got 3 10k resistors on it, one for air water and solar. I never unscrew the wires, I just pull the whole block off and the board shows an air temp error and kicks on freeze control.