Pentair Mastertemp 400 immediately shuts off after boot

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D

doddsilla

0
May 25, 2018
6
Atlanta
My heater was working fine, then about two weeks ago it started to shut down immediately after booting up (no blower, no ignition) and the buttons on the front would not work (had to use ScreenLogic to turn it on). I had a pool service tech take a look and he thought I needed a new control board, so I ordered a new one and replaced the old and got the same results with the new control board. I've yet to find any other users with this same issue, so I hope I'm in the right place. There's no error codes shown on the display and no LED's are lit on the back of the board. Video linked below showing the behavior I am experiencing.

MasterTemp 400 shutdown.mp4

Any guidance would be greatly appreciated
 
never seen that before, no lights on the back of the board for the 3 seconds it’s on? I would probably reconnect fireman switch jumper to start, just to rule out automation. Usually the screen doesn’t go blank like that unless there is an interruption in the fireman switch either from the automation or a broken/chewed low voltage line.
 
Thanks for the response. My heater is a 2018, so I'm not sure if it has a Fireman's Switch. I took a look at the spot where the switch "should" be (I think) and it looks like the yellow wires are connected to a control line that goes to the EasyTouch control box. I checked the fuse above it and the fuse was connected and still good:

1627907509899.jpeg
 
That is your “firemans switch “. Disconnect the control line at the two blue wire nuts. Then twist the two yellow wires together and put a wire nut on it.

You have restored local control to the heater. Now put your pump on and see if the heater works from its control panel.
 
Thx for the response. So, I followed your advice and disconnected the Fireman's Switch and connected the two yellow wires. I tried turning on the heater with the touchpad, and nothing kicked off. In order to bypass the touchpad, I removed the connection from the circuit board and shorted the 5th and 6th pins to start the heater. I'm now getting an E06 error for the stack flue sensor, which is to be expected because the wires had broken on the old one (maybe from repair tech). I have a new one being delivered tomorrow, so that swap should be pretty easy to do.

Takeaways from this is that I need to replace my touchpad (which should be well within my skillset) and that I need to diagnose/fix the Fireman's Switch in the EasyTouch. Any guidance on how to accomplish the latter? Is there a module in the control box I should be looking for and a simple part to replace, or do I need to check the relays or something else electrical?

Thanks again. This has been a huge help so far, and I feel like I would have gotten caught in an expensive rabbit hole with the repair tech trying diagnose this.
 
Get your heater running in local mode first. I don’t think there is anything wrong with your fireman’s switch or ET.
 
Update: Replaced the stack flue sensor and reset system breakers. I was then able to turn on the heater manually and the blower/ignition started pumping out hot water. Success! I then turned everything off, rewired the ET Fireman's Switch and tried to turn on the spa and heater with my phone controller. No luck! Heater showed the same behavior as before with it going through the boot cycle and then turning off. Now that I have diagnosed it's not a board/sensor issue any more, what are my next steps?
 
Looks like you have a pretty heavy duty communication linking between automation and firemanswitch so the chance of a break in the line is unlikely. I would start with rewiring connections at automation. Make sure terminal is snug on board, sometimes opening the flap will loosen it. I’m assuming all heat settings are correct.
 

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I think I solved it. I did a search on EasyTouch heater control problems and ran across this post:

Have manual heat, but no control from EasyTouch Panel

I turned the heater on and set the temp to 104 (the highest setting). Once I did that, the heater would activate using the phone control and it would respond to temperature changes on the phone by turning on or off. I'll keep an eye on it, but it turns out the fix to my problem was a $13 sensor and a couple of button presses and not the $760 dollars the pool tech wanted to charge me to replace the board.
 
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doddsilla said:
I checked the wiring on the board and it looks fine to me. I think if the wiring was bad, it would never send the signal to the heater to start in the first place.

View attachment 361189
Click to expand...
Is the water temperature accurate? It’s either there is no demand from board or what is listed above. I’ve never experienced a bad heater terminal so I don’t think that’s the issue.
 
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