mastertemp 400 not turning on without automation

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poolfusq

Gold Supporter
Jan 7, 2022
57
San Antonio, TX
A recent lightning storm surged some but not all of my equipment. My easytouch 8 panel is semi-toast and is getting replaced (upgraded to intellicenter). While its on order, I am manually running the filter pump which thankfully still works. I want to run the mastertemp 400 heater. When I turn on the panel, it starts up as normal for about 2 minutes before it gives up and just displays 12:00am. During those two minutes if I put it into spa mode, the heater will come on, fire up, everything is fine. But when the easy touch shuts off, the heater turns off... fine.

Then I turn the breaker off to the easy touch, leave the breaker on to the heater (which is also the breaker to a purifier ozone/uv thing, which lights up fine), have the pump on at 3000 rpm (lots of flow for the heater's flowmeter) but the heater doesn't turn on. Nothing on the display. Hitting pool on or spa on does nothing. Any ideas?
 
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The "Fireman's Switch" is a poor name for the 2 wire 24 volt AC remote control system of the heater.

The Fireman's Switch is a 2 wire control that can connect to automation such as the EasyTouch or IntelliCenter or to a timer.

The current is less than 500 milliamps (0.5 amps).

The firemans switch is the two center bottom terminals with the yellow wires on the block below the Fenwal box.

The right terminal has the fuse.

You remove the jumper and run a wire from one fireman's switch terminal to the one connection of the J19 terminal in Easytouch and then a wire from the other J19 terminal back to the other fireman's switch terminal or similar connections in other automation controllers.

The MasterTemp Installation Manual specifies to use 18 gauge wire with a minimum 3/64” (1.2mm) thick insulation rated for a temperature rise of at least 105°C. The area the wire passes through can get hot and melt wire insulation.

IntelliCenter: Insert the conductors into the GAS HEATER two-screw terminals (J2) on the upper right of the mother board.

EasyTouch Control System: Insert the conductors into the GAS HEATER two-screw terminals (J19) on the motherboard.

IntelliTouch Control Personality circuit board: Insert the two conductors into the GAS HEATER (J30) two-screw terminal on the left side of the Personality circuit board.
 
OK I got the heater working. But the increase temperature button doesn't work anymore. All the other buttons work. Is there some type of setting to this or did this surge possibly mess up the heater's button/display?

Any work arounds? It's set at the correct setting now from using the down arrow (85 pool, 99 spa).
 
JamesW said:
Shorting pins 1 to 2 briefly is the same as pressing "Spa On". Pressing a button on the membrane pad shorts a pin (2 through 5) to pin 1 to make a selection. Pin 1 is the lowest pin and pin 6 is the highest pin.

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.

Why did you short the pins? Were the buttons not working? Is the membrane pad connected now?

You can briefly short the pins as listed above to simulate pressing a button but don't leave the pins shorted.

The pins are so small and close together that it's hard to short any two without touching the others. So don't do it if you can't short only two.

If you can short only a single pin to pin one, the board should respond as indicated. If it doesn't, then the control board is bad. If all pin combinations work by short but not by pad buttons then the membrane is bad.

I would try the membrane pad first and then the control board.
Click to expand...
 

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JoeSchmoe said:
I found a pinout on an older post on this forum that said pin 1 to pin 6 is for the up button. So, I removed the membrane keypad ribbon cable (I removed power before unplugging), got my fused leads, and got on the ground to try jumpering pin 1 to 6 to simulate an up button press. My wife watched the keypad while I tapped the pins, and sure enough, the temp went up. Upon further inspection, my earlier attempt at cleaning the pins was not the greatest. Pin 6 was darker than the rest and pretty oxidized.
Click to expand...
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.


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Is a Max Temperature set?

Try going down and then back up..
_________________________________________________________________________________

MAXIMUM TEMPERATURE SET POINT

Access the control panel board on the underside of the top cover.

Locate the yellow button on the corner of the control board.

3. Push the Max. Temp. Set Point button on the back of the control board (see Figure 7).

The following sequence should happen:

A. The unit turns on and the POOL ON light will turn on.

B. Press the ^TEMP or TEMP pad (on TOP of the panel) to set maximum pool temperature.

C. Wait up to 30 seconds; the POOL ON light will turn off and the SPA ON light will turn on.

To override the time delay, push the Max. Temp. Set Point button again.

D. Press the ^TEMP or TEMP button on the control panel and set maximum spa temperature to 40°C (104° F) or less.

E. Wait up to 30 seconds; the SPA ON light will turn off and the unit will shut down.

To override the time delay, push the Max. Temp. Set Point button again.

1721226369106.png

MAXIMUM TEMPERATURE SET POINT
1. Unbolt and remove the door panels (see Figure 32).
2. Access the control panel board on the underside of the top cover. Locate the yellow button on the corner of the control board.
3. Push the Max. Temp. Set Point button on the back of the control board (see Figure 33).
The following sequence should happen:
A. The unit will come on and the POOL ON light will come on.
B. Press the STEMP or T TEMP pad (on TOP of the panel) to set maximum pool temperature.
C. Wait up to 30 seconds; the POOL ON light will go off and the SPA ON light will come on. To override the time delay, push the
Max. Temp. Set Point button again.
D. Press the STEMP or T TEMP button on the control panel and set maximum spa temperature to 104°F (40°C) or less.
E. Wait up to 30 seconds; the SPA ON light will go off and the unit will shut down. To override the time delay, push
the Max. Temp. Set Point button again.
4. Reinstall the access door panels
 
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