New member in Texas with Mastertemp HLS error

[dparsons44]

Hi pleased to be a new member !! Looks like a great place for me to get good advice

I have a 10ft diameter Cowboy pool with Mastertemp 125. It’s coming up to 4 years old, and I’m starting to get HLS errors as the pool approaches 90deg, for the last couple of degrees. It does eventually get there.

I just replaced the pressure, and 3 sensors on the manifold. It’s better, but still giving HLS just before reaching set temperature of 90deg.

Any advice welcome …

 

[ajw22]

Welcome to TFP.

Check the thermal regulator and bypass valve.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

The High Limit Switch prevents the Heat Exchanger outlet temperature from exceeding 135°F (±8°F).

The High Limit Switch is located in the lowermost well of the Manifold Adapter under the Manifold Switch Cover. Mounted below the AGS Switch, it is black to differentiate it from the AGS Switch, which is marked with a red dot.

The HLS is often caused by insufficient water flow through the heat exchanger. This can be due to several things:

• Thermal regulator not opening.
• External bypass open.
• Internal bypass broken.
• Pump too small or on too low rpm.
• Clogged filter.
• Scale in heat exchanger.

The High Limit Switch is p/n 42001-0063S

Start by checking the thermal regulator.