Another Mastertemp thread

[gator968]

Hi,

I have been reading as many old threads to try and understand why my heater kicked the bucket. I just found my multimeter and am going to dig around inside more based on the electrical flowchart.

While I am doing that I thought I would post my specific failure scenario to see if it can give a clue on what to hone in on.

Heater was working then disconnected for 2+ years during a messy reno.
Previous system was Easytouch, current system is Intellitouch.
Heater is connected 220v with the proper plug and the firemans switch currently jumpered.
On initial power up, heater came on and started working for a couple of minutes. Then the fuse blew.
After replacing the fuse, heater boots up normally ( r13 on display) then does nothing. No buttons elicit any response.
There are no lights on control board or on ignition control board.

Thanks in advance!!

-Kevin

 

[gator968]

Seems that I missed pressing the spa on button on the control panel. After pressing the button heater came on again for less than a minute and blew the fuse again.
I imagine something may be gunked up inside. Builder did not bypass the heater during pool replaster. Going to do a bit more research, as my failure condition changed from what I thought previously.

 

[ajw22]

Show us a picture of the Fireman's Switch jumper. If done wrong and a wire is shorting to ground it will blow the fuse.

 

[gator968]

Here is a picture of before ( coming from the header on the intellicenter ) and after jumping. Both have the same end result.

 

[ajw22]

OK, you have the standard yellow jumper installed.

Any signs of rodents in the heater? They like to chew on the wires and will cause many problems.

 

[gator968]

OK, you have the standard yellow jumper installed.

Any signs of rodents in the heater? They like to chew on the wires and will cause many problems.

Thanks for the replies!!

No signs of rodents from what I can tell. There are alot of areas which appear to have had moisture, mainly near the manifold ( one bolt rusted off ). But all wires seem intact.

Is there by any chance any sensor that if bad/shorted is more likely to cause a blown fuse as opposed to just an error code? I imagine that there may have been stagnant pool water in the heater for years. Are there any moving parts that if scaled up could cause a current overload?

BTW, here is a picture of the rusted off bolt. I imagine getting these bolts replaced should be an item on the bullet list to do.

 

[ajw22]

Rusted bolts, especially the lower left bolt, is a sign of a leaking heat exchanger or cracked manifold.

Most sensors are not part of the 24V power loop the fuse protects. I think only the Water Pressure Sensor is on the 24V loop. Check the diagram in the manual.

There are few moving parts in the heater other than the blower which runs on a seprate 12oV feed.

 

[gator968]

Rusted bolts, especially the lower left bolt, is a sign of a leaking heat exchanger or cracked manifold.

Most sensors are not part of the 24V power loop the fuse protects. I think only the Water Pressure Sensor is on the 24V loop. Check the diagram in the manual.

There are few moving parts in the heater other than the blower which runs on a seprate 12oV feed.

Thanks! I’ll take a look through the manual/troubleshooting guide for that. Still trying to figure out ladder diagrams, but I should be able to dig in.

I believe that since I have the ASME bronze manifold, I did not get a good fit on the thread with the pvc and it leaked a bit whenever my bypass included the heater circuit. I guess I am hoping the moisture came from the outside as opposed to the inside of the manifold .

 

[Poolbreh]

Inspect the board for burns. It could be a short.

 

[ajw22]

Inspect the board for burns. It could be a short.

We have seen dead insects and reptiles shorting out boards.

 

[ajw22]

How old is your heater?

Find the sticker with the manufacturing date on it.

Pentair has made changes over the years and revised the manual but they only have the latest manual on their website. I have a collection of older manuals and may be able to provide a more accurate wiring diagram.

 

[gator968]

Uggh.. poor little guys :-(. No visible burns on top of board, but I wouldn’t put it past something getting on the back side and shorting it out. Ill remove the panel and check for shorts and reseat all connections, throw in another fuse and see if failure condition is the same

 

[ajw22]

Below is a MasterTemp Wiring diagram from 2015.

Disconnect the sensor connector marked in green and the Fenwal connector marked in blue from the board.

Then try powering up the heater.

If the fuse blows then the board is bad since all that is connected to it is the 24V power.

If the heater does not blow the fuse then connect the blue Fenwal connector. Power it us and see if the fuse blows.

If the fuse is still good then connect the sensor connector and try powering it up.

Report what you learn.

 

[gator968]

How old is your heater?

Find the sticker with the manufacturing date on it.

Pentair has made changes over the years and revised the manual but they only have the latest manual on their website. I have a collection of older manuals and may be able to provide a more accurate wiring diagram.

 

[ajw22]

Here is the ladder diagram showing all the sensors on the 24V loop. The color coding corresponds to the connectors to the PCB above.

All the green sensors connect to the PCB through the green connector on the left side.

The blue indicates connections to the Fenwal module.

If it is a sensor shorting you can use your multimeter and test for shorts from the pins in the green conenctor to ground.

 

[gator968]

Thanks!! Heater was day 283 of 2014 so this should be the correct manual.

Not sure if I will get the control board off today before I have to call it quits for the day BUT I did see a potentially huge issue. The gas inlet has been rotated upon inserting/removing the iron pipe. When I pick this up tomorrow I will see what I can do to get it reoriented and check connections!

 

[ajw22]

Given the gas valve is janky you can pull the 24V connection off the gas valve and see if the fuse blows.

A bad gas valve must be replaced and is not repairable.

 

[gator968]

Given the gas valve is janky you can pull the 24V connection off the gas valve and see if the fuse blows.

A bad gas valve must be replaced and is not repairable.

Well looking at the pics of the gas valve in proper orientation, I can’t see how the contacts on top of the valve are not shorted to ground.

Is there any way to test the gas valve’s operation ( if it doesn’t blow fuse when harness is disconnected ) to determine if there is a problem with the valve, or just a short on the top connectors? Or is the guideline to always replace the valve if something like this happens?

Thanks again!!

 

[ajw22]

Is there any way to test the gas valve’s operation ( if it doesn’t blow fuse when harness is disconnected ) to determine if there is a problem with the valve, or just a short on the top connectors? Or is the guideline to always replace the valve if something like this happens?

You can test the gas valve if you have a 24V AC transformer and can connect power to the gas valve. If you hear a click and smell gas then the valve opened.

 

[gator968]

You can test the gas valve if you have a 24V AC transformer and can connect power to the gas valve. If you hear a click and smell gas then the valve opened.

I can bring out a bench power supply instead of fiddling with a transformer . Is it just a relay inside, power = open, no power = closed? Are there any safety issues that could be present that would push me to just buy a new gas valve, or if I ensure closure and opening I am good??

Also, any tips on the vacuum tubes to use to replace the ones on the valve and blower? Are they standard, or do I need to purchase Pentair air orifice ones?Regardless of the operation of the valve, I should probable replace these, they appear to have degraded over time.

Thank you again!!