Mastertemp 300

[bfithian]

My heater turns itself on in spa mode and I don't have a spa. I tried unplugging the keyboard ribbon as discussed in a different post but that didn’t resolve the issue. What would be my next logical step in accessing the issue? I am not getting any error codes either.

 

[ajw22]

Welcome to TFP.

Is your heater connected to any automation?

How old is your heater?

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[1poolman1]

My heater turns itself on in spa mode and I don't have a spa. I tried unplugging the keyboard ribbon as discussed in a different post but that didn’t resolve the issue. What would be my next logical step in accessing the issue? I am not getting any error codes either.

Pool mode and Spa mode are just different temperature settings. Does the board respond to any input from the touchpad? You can try jumping the pins as in the following:
1 to 2 ...spa on.
1 to 3...pool on.
1 to 4...heater off.
1 to 5...down arrow.
1 to 6...up arrow.
With the connection to your right the pins are numbered top to bottom.
If you get no response it indicates a faulty board.

 

[bfithian]

The board responds to heater on and off, but not to pool mode. Once I turn it off, a few seconds later it turns right back on in spa mode. By itself the display shows what I think is the current temp then it flashes a higher temp, which I'm guessing is the flue temp. When you say jumping you mean taking a wire and touch the two pins to see the response? My board is mounted to the upper side of the unit so it makes it difficult to see the pins.

 

[ajw22]

The board responds to heater on and off, but not to pool mode. Once I turn it off, a few seconds later it turns right back on in spa mode. By itself the display shows what I think is the current temp then it flashes a higher temp, which I'm guessing is the flue temp. When you say jumping you mean taking a wire and touch the two pins to see the response? My board is mounted to the upper side of the unit so it makes it difficult to see the pins.

Are these behaviors with the keypad installed or removed?

Everything you describe is consistent with a bad membrane keypad.

 

[bfithian]

I unplugged the keypad and the heater still comes on.

 

[ajw22]

I unplugged the keypad and the heater still comes on.

You did not answer my question above.

Either you have a bad board, a bad keypad, or frayed wiring.

 

[1poolman1]

I unplugged the keypad and the heater still comes on.

The board "remembers" the last setting that was input. Touchpad is just the input device, like a computer keyboard. Jumping, yes momentarily using a small piece of wire to touch the different pins. The wire takes the place of the touchpad.

 

[bfithian]

You did not answer my question above.

Either you have a bad board, a bad keypad, or frayed wiring.

Wiring looks good. U

The board "remembers" the last setting that was input. Touchpad is just the input device, like a computer keyboard. Jumping, yes momentarily using a small piece of wire to touch the different pins. The wire takes the place of the touchpad.

So if I let it come on, shut it off with the keypad, then quickly unplug the keypad, the board should remember the being shut off and not come on?

 

[bfithian]

You did not answer my question above.

Either you have a bad board, a bad keypad, or frayed wiring.

Isn't unplugging the keypad the same as removing it?

 

[bfithian]

The board "remembers" the last setting that was input. Touchpad is just the input device, like a computer keyboard. Jumping, yes momentarily using a small piece of wire to touch the different pins. The wire takes the place of the touchpad.

If it wasn't raining here I would do that now. I unplugged the 12 pin 120v plug for now so I can still run my filter and get my pool clean.

 

[1poolman1]

Isn't unplugging the keypad the same as removing it?

Yes. If you unplug the touchpad with the heater off and it turns back on without it plugged back in it is most likely a bad board.

 

[bfithian]

Thanks, I will try that today after work.

 

[bfithian]

Thanks, I will try that today after work.

I unplugged the keypad after switching off the heater and it worked, the heater did not turn back on. I waited about 5 to 7 minutes then turned the pool pump off, then turned it back on and the heater did not come on. As you were saying before, is this a good indicator that the keypad is bad? I'm ordering one from Amazon today. Thank you

 

[bfithian]

Next question: How do you replace the membrane? Looks in the pictures that it just sticks to it.

 

[1poolman1]

Next question: How do you replace the membrane? Looks in the pictures that it just sticks to it.

Peel off, clean the area as best you can, stick on. Be sure to align the openings for the service lights. Also, push the ribbon cable all the way through before removing the protective paper or it can get stuck to the membrane.

 

[bfithian]

Wow, perfect fit for 22 bucks. Thank you again for the help. It's working great.