Pentair MasterTemp not responding to ScreenLogic

Jimrahbe said:

Chas,

I assume you are using a two wire fireman's connection.

If so, that is all that SceenLogic will do.. You are just supposed to set the heater to full hot. The ScreenLogic will close the small heater relay and this tells the heater to heat. When the water heats up to the set point, the relay will open and the heater will shut off.

Thanks,

Jim R.

Click to expand...

Jim,

Thanks for your reply. Yes, it is the two-wire connection, exactly the same as it was on my previous 2015 model MasterTemp 250. But with the prior model I could adjust the setpoint from within ScreenLogic which was, and remains, set up to do so. Only now changing the setpoint from within ScreenLogic doesn't actually do anything. Have they taken away this feature for some reason?

Regards,
Chas

Jimrahbe said:

Chas,

The automation just closes the heat relay.. That is all it does.

Find the two wires attached to the heater relay and short them together (That is all the relay does).. It the heater fires up, that means the relay is bad, or the chip the drives the relay is bad.

If the heater does not fire up, that means the heater, or the heater settings are bad. Or the 2-wire cable could be bad or not connected at the heater end.

Thanks,

Jim R.

Click to expand...

Jim,

Got it. I figured out my issue. With the 2015 MasterTemp, pulling the fireman's switch jumper and attaching the two control wires had the effect of completely disabling the MasterTemp control panel in favor of using the Intellitouch temperature sensor plus ScreenLogic. With this 2023 model, the control panel on the heater is not fully disabled. When ScreenLogic sends a heater on command, you can still adjust the setpoint in the heater's internal system and that setpoint acts as a cap and the heater will stop firing when that cap is reached even if the setpoint assigned within ScreenLogic is a higher value. In my case, the internal heater setpoint was 80 degrees and the ScreenLogic setpoint was 81 degrees. Thus the heater overrode ScreenLogic. Once I set the internal heater setpoint to "max", leaving the ScreenLogic setpoint at 81, the pool duly heated to 81 and then the heater stopped firing. Not sure why this system logic was changed in the newer heater. Anyway, thanks very much for your input.