Pentair MasterTemp 400 PS issue...but not PS itself.

[zdfoster]

I've tried a few things and dug around on this forum with no luck...so creating my own post.

I have an old (12yrs) Pentair MasterTemp 400. I turned it on this spring and the unit turns on and fires up but flashes the Service System before the blower kicks on and starts heating...then the Heating led turns off and the Service System turns on.

I checked the back of the Control board and the PS led was turning on and off every so often. The unit still works through all of this but then after maybe 3-4 minute the unit shuts off.

So I checked the flow and everything and all switches are normal. Backwashed and made sure all baskets were empty.

I went and got a new PS and installed and that did nothing. Same results. So using wire, I jumped the PS and it is still happening.

I checked all the wires and there are zero evidence of rodents/loose wires.

So I thought maybe a bad control board...so I replaced that. Still having the same issue.

Is there anything else that can be triggering the PS error other than the PS switch?

Thank you for any help!!

 

[ajw22]

Welcome to TFP.

Did you check the PS wires and connectors for continuity?

Any sign of rodents in the heater?

Did this heater ever work for you?

 

[zdfoster]

Thx for the reply but yes, checked the whole unit and there is zero signs of rodents and all the wires are in good condition. Everything is seated well.

Yep, the heater work all last year with zero issues.

 

[zdfoster]

And before anyone asks, I don't have a bypass valve, so that can't be it

 

[ajw22]

Post pictures of your equipment pad and heater.

 

[zdfoster]

Here is the heater.

Tried to show that the board has the led 'service system' and 'heating' leds on and then the back of the board when the PS led is on as well.

 

[ajw22]

You do not have a genuine Pentair PCB. Many people have had problems when using clone PCBs that worked when they put in a genuine Pentair PCB.

I realize you are showing the same problem with your old PCB and the clone. But they are not as identical as claimed. We don’t know how to diagnose problems with those boards.

It will cost you more money to try a genuine PCB and you have to decide how much you want to throw into an old heater.

I suggest you install your old Pentair PCB. Then jump the PS terminals at the connector at the board.