Pump Turn On Randomly Results In Either Normal Pressure or Very High Pressure

[NewToTFP]

Experiencing strange behavior wherein any given engagement of the pump (Pentair 342248) presents either normal or very high pressure at random. In the high pressure state if I shut off the pump and vent the filter (Triton TR100, newly installed along with accompanying multiport valve) for about 5 secs and then reengage the pump I get about an 80% success rate of it going back to normal pressure. Post venting the pump lags a bit recovering prime and goes to normal, or it ramps and goes to high pressure. Either results in small air bubbles in the pump filter and air out of the returns.

Freshly backwashed, the filter might go from 33psi to 20psi and back again if I cycle the pump off/on manually and if I vent it the success rate increases significantly. The filter continues to create gradual pressure increases as it does it's job cycle over cycle, but the behavior then might then go from 23psi when mildly dirty to 33psi if I (the programming) turn the pump off and then back on. That success rate has diminished over time and after replacing everything absent the pumps (+booster for cleaner) I'm at a loss.

Is it a clog acting as an intermittent diaphragm, is it the pump failing in some way? Any insight would be greatly appreciated.

In ground
40.000 Gallons
Jandy RS controller and newly installed valves
Integrated Spa with shared suction and return
3x Skimmers
2" Lines throughout

 

[ajw22]

Welcome to TFP.

I would check that you have the correct MPV for your filter and/or the input and output lines were not reversed.

Post pics of your filter and MPV if you want us to have a look.

 

[JamesW]

It might be a sticky pressure gauge.

When it shows a high reading, tap the gauge to see if it goes back down to the lower pressure.

 

[NewToTFP]

Welcome to TFP.

I would check that you have the correct MPV for your filter and/or the input and output lines were not reversed.

Post pics of your filter and MPV if you want us to have a look.

Picture attached. Thanks for the help.

 

[NewToTFP]

It might be a sticky pressure gauge.

When it shows a high reading, tap the gauge to see if it goes back down to the lower pressure.

Unlikely as it was exhibiting the same behavior on the old gauge before I replaced the sand filter. Will give it a try anyway though.

 

[ajw22]

Show me pics where the model numbers of the filter and MPV are readable.

 

[NewToTFP]

Show me pics where the model numbers of the filter and MPV are readable.

 

[NewToTFP]

Just as a follow up I solved the issue. It was a bad check valve in line before the heater where the flap had come loose and was acting as an intermittent diaphragm depending on how it came to rest inside of the housing when the flow stopped.