Heater not working - Pentair MasterTemp 400

[Drbiii]

Last week I tried to heat my pool spa and noticed the heater wasn’t working.

I havr a Pentair MasterTemp 400 and when I switch the system to spa, the heater turns on and looks like it’s starting to go through the process…(displays 128, displays an “r13” code, displays “service system”, then when pump turns on it switches to “service heater”. Theres no error code but the display does show a “1”.)

No click from the igniter, no blower.

Any insights into where to start?

NOTE: I’m planning to pull the top panel today to see if there are any of the back panel LEDs lit up.

 

[ajw22]

Is the heater connected to automation?

Let us know what the LEDs show.

You also have to check the LED on the Fenwal box.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[Drbiii]

Ok. Just pulled it apart. And tried to run the system.

Back panel showed the PS light on briefly but then turned off. This time I got a “Service Heater” light and did get an E01 code.

It is connected to automation. Pentair Intellitouch i9+3

Opened the age well box. No LEDs in there.

 

[Drbiii]

I also noticed a little rodent chewing on the automation wire but I don’t think that’s the cause

 

[JamesW]

LED 07 is a temp sensor fault.

Follow the brown wires from the board to the thermistor and replace the wires if they are damaged.

If the wires are ok, replace the thermistor.

The following are the LEDs:

1. .....PS (Pressure Switch)
2. .....HLS (High Limit Switch)
3. .....SFS (Stack Flue Sensor)
4. .....AFS (Air Flow Switch)
5. .....AGS (Automatic Gas Shutoff).
6. .....Service System
7. .....Thermistor
8. .....Heating
9. .....Pool On
10. ...Spa On
11. ...Service Heater.

 

[JamesW]

• The "E01" code indicates an open water temperature sensor, also called the thermistor on the parts diagram.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[ajw22]

If the rodent chewed on one wire, he probably chewed on others.

The temperature sensor is in the manifold and a wire runs from the sensor to the board.

You need to examine all the wires and replace any that show marks.

 

[JamesW]

42001-0053S GENUINE Pentair MasterTemp Sta-Rite Max-E-Therm Pool Heater Thermistor.

Pentair Thermister for Max-E-Therm, MasterTemp Heaters - 42001-0053s - INYOPools.com

42001-0053S - THERMISTER (42001-0053S)

www.inyopools.com

 

[Drbiii]

Just found the problem. Looks like something chewed through ALL the sensor wires.

Do I need a whole new harness or can I just add a butt connector?

Looks like one of the sensors is chewed right at the connector? Are these standard blade connector sizes or do I need to get them from Pentair???

 

[JamesW]

Are these standard blade connector sizes or do I need to get them from Pentair???

Standard 1/4" female spade terminals.

Do I need a whole new harness or can I just add a butt connector?

You can use connectors.

 

[JamesW]

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[ajw22]

From Pentair MasterTemp Heaters - Further Reading

Wiring can get chewed up by critters.

Pentair says:

If any original wiring supplied with this heater must be replaced, the installer must supply (No. 18 AWG, 600V, 105° C. U.L. approved AWM low-energy stranded) copper wire or its equivalent.

Line voltage field wiring should be 14 gauge, with a circuit capacity of 15 Amps.

The old non-connected heater's complete replacement wiring harness (p/n 42001-0104S) is being replaced by the replacement wiring harness for the Connected Heater (p/n 461107). The new Wiring Harness for the Connected Heater has adapters to make it backward compatible with the non-connected heater.

 

[Drbiii]

A few other questions as I’m planning to fix this mess…

1. Do with wires have a certain polarity? How do I know when wire goes on which side of the sensor?
2. Should I go ahead and replace the sensors while I’m in there?
3. While I was cleaning out the case it looked like there was some kind of insulation in there at some point. I assume it goes around the tub. Is it worth it to replace that or just leave it alone??

 

[JamesW]

I would not spend $300.00 on wiring.

 

[Drbiii]

I would not spend $300.00 on wiring.


View attachment 623399

Wow! Yeah…definitely not getting the whole harness.

 

[ajw22]

1. Do with wires have a certain polarity? How do I know when wire goes on which side of the sensor?

Sensors do not have a polarity.

2. Should I go ahead and replace the sensors while I’m in there?

How old is the heater?

You run the risk of getting a new but bad sensor.

3. While I was cleaning out the case it looked like there was some kind of insulation in there at some point. I assume it goes around the tub. Is it worth it to replace that or just leave it alone??

Show us pictures of what you found.

The burner can has insulation on the top and bottom. If the rodents tore it up, it needs to be replaced, or the heater can melt itself. Take careful stock of all the damage before you begin spending money on parts.

Rodents can damage a heater to where it makes more sense to replace it instead of repairing it.

 

[Drbiii]

Sensors do not have a polarity.



How old is the heater?

You run the risk of getting a new but bad sensor.



Show us pictures of what you found.

The burner can has insulation on the top and bottom. If the rodents tore it up, it needs to be replaced, or the heater can melt itself. Take careful stock of all the damage before you begin spending money on parts.

Rodents can damage a heater to where it makes more sense to replace it instead of repairing it.

View attachment 623403
View attachment 623404

These insulators appear to be inside the tub (they’re showing underneath the lid, right)?????

I saw insulation outside of the tub. It looks like there was still some underneath it, but this pic shows all the torn up insulation around the tub (yellow stuff)

 

[ajw22]

The rodents could have dragged that stuff in. Looks like they had quite a party in there.

 

[Drbiii]

The rodents could have dragged that stuff in. Looks like they had quite a party in there.

Ha. Yes they did!

What's interesting is I just used the heater a month ago with no problems so this appears to be fairly recent.

Good thing is it looks like it was just those sensor wires so I’ll is those and see what happens. I may try to find some stainless steel mesh to line the inside of the panels for the future while I’m in there.

 

[JamesW]