MasterTemp 400 display turns on and immediately off

[vmwm5]

Hi Folks,

I have a Pentair HeatMaster 400 (1.5 years old) that does the following when I turn on the heater from the app or the EasyTouch panel:

1. Display comes on with "888"
2. service heater light on
3. service system light on
4. display shows "128 r14"
5. then display and lights turn off

I don't hear the heater "fire up" or may any noise (not that I'm sure I'm even supposed to). The water temperature is 89f. It was working up until 4 days ago. I tried replacing the pool temp sensor with a new one, but still does the same thing. Been working for 1.5 years (newly built house and pool at the same time) with no issues.

Any thoughts or guidance?

Thanks in advance,

D

 

[ajw22]

Welcome to TFP.

Steps 1 through 5 are the normal heater pwoer up sequence. Nothing wrong there.

Is your heater connected to any automation?

With the display off the heater is waiting for call for heat from the control panel or automation. What do you do to turn on the heat?

 

[vmwm5]

Thanks for the quick reply.

I have used both the screenlogic app, and the easytouch panel to turn on the heater. Both elicit the same results posted.

 

[vmwm5]

To your automation question, only automation would be the easytouch scheduling, nothing else otherwise.

 

[ajw22]

Then the EasyTouch is controlling your heater using a 2 wire connection between j30 on the ET and the "firemans switch" on the MasterTemp heater.

Either the relay on your ET board has failed, the 2 wire connection has failed, or you may have rodents in your heater who chewed on some wires.

First thing I would do is open the heater and check the connection shown below.

You have a multimeter?

See page 17 in https://www.pentair.com/content/dam...em_Load_Center_Installation_Guide_English.pdf

and ,,,

Heater Control with Automation - Further Reading

www.troublefreepool.com

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[vmwm5]

You rock! I'm going to check those items out now...will post my findings, thank you again for the guidance.

 

[Poolbreh]

If there is a display, there isn’t abroken link in the fireman switch. Since you have used it up to 4 days ago I’m assuming your settings are correct. You didn’t mention pool or spa buttons were enabled(one should be on and set to max settings) automation just turns the heater off and on based on temperature sensor integrated in the automation. If there is no demand On heater itself it won’t fire. Yes you should hear it fire up.