Carel controller settings

[Jack_H]

1 hour ago, dpmiller said:

are you reading the tank temperature off the controller, or off some other thermometer on the tank? Or the flow temp? Certainly on our iVT9 the flow exceeds tank setpoint so the top of the tank ends up quite a bit warmer than setpoint...

Do you actually see the tank actively heating to 50c or does it soak up a bit after shutting down @45? 

I'm reading the temperature of the cylinder temperature sensor which is displayed in the controller and app - the sensor is halfway up the cylinder...

Edited yesterday at 19:31 by Jack_H

[dpmiller]

quite possibly just the stratification settling down in the tank, I'd say

[JohnMo]

12 hours ago, Jack_H said:

the issue I have is, my DHW setpoint is set to 45 degrees, however the tank keeps being heated to ~50 degrees. I'm assuming it's using the weather comp setpoint, but can't quite get my head around how that works for DHW.

Very unlikely to be WC as that doesn't normally work on dhw, as it aims to meet a setpoint. I would look at any hysterisis values in the controller. Is there an target plus x degs hysterisis programmed? From the above images, you looking for the stop temperature differential.

[Jack_H]

2 hours ago, JohnMo said:

Very unlikely to be WC as that doesn't normally work on dhw, as it aims to meet a setpoint. I would look at any hysterisis values in the controller. Is there an target plus x degs hysterisis programmed? From the above images, you looking for the stop temperature differential.

This is what I thought. My hysteresis is set to 10 degrees, however I can't see anything in the controller that looks like a differential stop for dhw...

[JohnMo]

12 minutes ago, Jack_H said:

My hysteresis is set to 10 degrees, however I can't see anything in the controller that looks like a differential stop for dhw..

It maybe doing plus 5 and minus 5? If you are getting 5 degs of overshoot, set the target lower and decrease hysterisis?

[Jack_H]

7 hours ago, JohnMo said:

It maybe doing plus 5 and minus 5? If you are getting 5 degs of overshoot, set the target lower and decrease hysterisis?

Yeah, I'll give this a try and report back. Cheers 

[Jack_H]

Well that didn't seem to make a blind bit of difference...

 

DHW setpoint changed to 40 degrees and hysterisis set to 5 degrees.

 

DHW heating cycle seemed to kick in around 40 degrees cylinder temp and went on to reheat to ~50 degrees. 🤷