Pentair Master Heater Not Firing

[TSpielman]

Greetings everyone... I could use some help.

My heater stopped firing after years of reliable use (heater is about 10 years old). I read a bunch of forums here, including the great HowTo on the heaters in general.

Following those troubleshooting steps, I was able to narrow the issue to a relay failure on the Fenway board. I considered just buying a new relay, but in the interest of "Peace of Mind," I bought a brand new Fenway board (35-662944-013) and installed it.

The heater fired right up. Yay.

But a few hours later, I swapped out of service mode to standard mode and tried to turn on the heater again, and once again, the heater is not firing.
I need to wait for daylight to disassemble and troubleshoot again - but I am worried that something else is going on or worse, causing the relay to fail.

The display does periodically display "91," but I don't know what that indicates, and a search on google doesn't show anything significant.

Does anyone here have any advice or guidance on what may be going on?

Thank you!

P.S. For what it is worth, prior to the initial heater failure, I had been running the heater continuously for about two weeks, keeping the pool at 76 with the outside / ambient temperature ranging from 45-80 (depending on day). Maybe soot buildup somewhere????

 

[ajw22]

But a few hours later, I swapped out of service mode to standard mode and tried to turn on the heater again, and once again, the heater is not firing.

Welcome to TFP.

Is the MasterTemp heater controlled by an EasyTouch system?

Having replaced the Fenwal module, you may have disconnected the fireman switch control wire to the EasyTouch.

Jumper the fireman switch in the heater to put the heater under local control.

If the heater does not start from its control panel then we know to look for problems in the heater.

If the heater starts from its control panel then we look at the EasyTouch for the problem.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[TSpielman]

Welcome to TFP.

Is the MasterTemp heater controlled by an EasyTouch system?

Having replaced the Fenwal module, you may have disconnected the fireman switch control wire to the EasyTouch.

Jumper the fireman switch in the heater to put the heater under local control.

If the heater does not start from its control panel then we know to look for problems in the heater.

If the heater starts from its control panel then we look at the EasyTouch for the problem.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

Thank you for the guidance …. But I did NOT change the fireman switch in anyway, and the heater firesd up the first time via the easy touch panel while I was in service mode.

It subsequently decided to no longer fire up.

(Edit/add) but I will try your idea of bypassing the easy touch panel to rule it out as a problem. Thank you.

 

[TSpielman]

Update (still not solved, but problem seems to be settings/configuration/electrical)

After a bunch of troubleshooting this morning, I determined that the heater is working (yay), but only when the easytouch is set to Pool mode.
When I turn it to Spa mode, I see the following behavior:
- Enabling spa heater after the pool is in spa mode will turn on the heater, but it will not fire up. No relay, no blower, no gas.
- Having the pool heater on, enabling the Spa heater and then swapping to spa mode .... the heater will stop burning and blowing after a few minutes.

For what it is worth, the membrane panel always has "spa" lit, even in pool mode. I do not know if that is normal or not.
I have also traced the wiring from the heater to the EasyTouch and there is no apparent damage to the wiring anywhere.

I hope someone here can help me identify the cause of the problem, as another google search was unsuccessful.

Thanks in advance!

 

[TSpielman]

One more clarification…..

I have an AquaLink RS controller, not EasyTouch.

 

[ajw22]

For what it is worth, the membrane panel always has "spa" lit, even in pool mode. I do not know if that is normal or not.

That is normal. The heater does not know or care where the water is coming from.

And there is no communication between your Aqualink and the MasterTemp other than turning it on and off.

 

[ajw22]

One more clarification…..

I have an AquaLink RS controller, not EasyTouch.

What REV level is your Aqualink and what controller do you use to control it?

Jandy Aqualink RS - Further Reading

www.troublefreepool.com

 

[TSpielman]

@ajw22 - thanks for the quick replies

#1. Appreciate the clarification on the SPA LED. I assumed it didnt matter, but wanted to be sure.
#2. Aqualink RS controlled only by handheld PDA.
PDA: 6.0, J-BOX: 4.0, HANDHELD: 3.0

Also, to be 100% clear - the Aqualink DOES seem to turn the heater on in spa mode, as the heater membrane goes through the bootup cycle (888, 128, r13). It just doesn't activate the relay, blower, gas and igniter.....

 

[ajw22]

I don't know the way around the Aqualink PDA. @PoolGate may be able to help.

I would disconnect the 2 wire heater control at the Aqualink PCB relay.

Put your multimeter on the heater relay two screws and check for continuity. You should see the relay open when the heat is OFF, and the relay closed when the heat is ON. Test it in POOL mode and SPA mode. If the relay opens and closes in POOL mode and stays open in SPA mode then you have an Aqualink problem. Somewhere in your PDA you do not have heat turned on for the spa.

You need to isolate if the problem is in the heater, which it looks like it is not; the firemans switch control wire or Aqualink relay on the PCB; or in the Aqualink use.

 

[TSpielman]

Once again - thanks for the tips.

I want to start with jumping the fireman's switch and first making sure that the heater is actually set to 104.

but please excuse my ignorance. Do I need to short two terminals in the heater box, or remove some connectors, or what?

 

[ajw22]

Remove the two yellow wire nuts and separate the wires.

Twist the yellow wires together and put a wire nut on it to restore the MasterTemp local control panel.

 

[TSpielman]

Well.... it may have been the membrane shorting out the buttons.

The ribbon cable looked dirty/corroded. I removed it, cleaned it up, and now I think that the heater is working for the spa.
I have ordered a new membrane (only $17, so its worth replacing).

I will monitor the situation and provide a final update to hopefully close the issue.

Many thanks for your help @ajw22 !

 

[ajw22]

Glad we could help.

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[TSpielman]

Update (problem is back)

After heating up the hot tub, the temperature seemed t peak at 98F instead of 104F.
I went back outside and the buttons have become unresponsive again, and the LED has reverted from POOL to SPA.

Even worse, now the heater wont fire even when I jump the fireman's switch (and the button pad continues to be unresponsive).

I supposed I will have to wait until the new button membrane arrives and see if that does address the problem.

 

[TSpielman]

Update: issue solved
Problem: pentair heater only fires for pool mode and not spa mode
Solution: button membrane on heater failed and was shorting out, inhibiting proper heater operation. Replaced with new membrane (<$20)

For future readers, I just wanted to close this issue out. A faulty membrane caused some very odd behavior, and a replacement proved to be easy and cheap, resolving the issues.

 

[ajw22]

We are glad we could help you get your heater running.

TFP is a member supported 501(c)3 non-profit that is volunteer staffed and has no ads. Your support keeps the servers running so we can be here to help you. It is helpful if you consider supporting TFP so we can be here to help in the future...

Become a TFP Supporter

Help Support TFP Trouble Free Pool is run by a dedicated group of volunteers that … Read more…

www.troublefreepool.com