Pool Heater Broke Following Lightning Event

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Usnavy1610 said:
Thank you again for your feedback and guidance. Quick update:
- Disconnected control wire from EasyTouch and jumpered Fireman’s Switch. Turned on breakers, everything stays off as configured. Turn on main pool pump, 240VAC power is immediately applied to MT400 and blower turns on immediately and stays on as long as main pump is on, even when I’m not in Spa mode (same as before).
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Mode of EasyTouch does not matter to the heater with control wire disconnected.

You control heater with its local keypad.


The MT400 keypad does work (SPA ON, POOL ON, HEATER OFF, TEMP UP/DOWN). With desired temp set well above ambient, “Heating” light does turn yellow, but heating never turns on and ultimately “Service Heater“ comes on. Rear Control board goes through a series of typical various flashes, but always ends off on LED 9 or 10 (Pool or SPA) GREEN, and LED 11 (Service) RED. All the other error lights are off.
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Does heater turn off and stay off when you press HEATER OFF?

And try and turn on when you press SPA ON or POOL ON.

Usnavy1610 said:
- With the EasyTouch control wires disconnected, I measured continuity across them. They always stayed open, even when EasyTouch Spa was on and I set the heat temperature several degrees above ambient (the red flame would show on my ScreenLogic app). Is it possible the relay in the EasyTouch needs to see the 24VAC in order to close the circuit?
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You may have a bad wire if you are testing from the end that was connected to the heater.

Open the EasyTouch upper cabinet and test the heater relay at its connection on the PCB.
 
ajw22 said:
Mode of EasyTouch does not matter to the heater with control wire disconnected.

You control heater with its local keypad.




Does heater turn off and stay off when you press HEATER OFF?

And try and turn on when you press SPA ON or POOL ON.



You may have a bad wire if you are testing from the end that was connected to the heater.

Open the EasyTouch upper cabinet and test the heater relay at its connection on the PCB.
Click to expand...
When I press SPA ON or POOL ON, the HEATING lamp will come on but the heater never actually fires Up. Ultimately the SERVICE HEATER comes on and the HEATING light turns off. When I press “Heater Off”, all of the front panel lights turn off. However, the blower keeps blowing. Seems whenever power is provided to the heater, which is whenever the main pump is on, the blower is always blowing. Again, the heat never actually turns on.
I did test the relay from the heater end. I will try tonight when I get home.
 
JamesW said:
Typically, you want the heater powered all the time and not based on the filter pump relay.

The heater should be allowed to cool down if the pump is turned off.

The fan should run for about a minute if the pump turns off.

If the heater is trying to fire and it does not fire and it says Service Heater with no error LEDs, then that is usually a flame sensing issue and this should cause the red LED on the Fenwal Ignition Controller to blink in one of the patterns indicated on the controller.

You might have a bad igniter or a bad gas valve.

Check for 24 VAC at the gas valve and check for 120 volts at the ignitor during call for heat.

Check the amperage going to the ignitor.

Check the resistance of the ignitor.
Click to expand...
Thanks. I will try these tonight.
 
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Usnavy1610 said:
When I press SPA ON or POOL ON, the HEATING lamp will come on but the heater never actually fires Up. Ultimately the SERVICE HEATER comes on and the HEATING light turns off. When I press “Heater Off”, all of the front panel lights turn off. However, the blower keeps blowing. Seems whenever power is provided to the heater, which is whenever the main pump is on, the blower is always blowing. Again, the heat never actually turns on.
I did test the relay from the heater end. I will try tonight when I get home.
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I am trying to figure out how balled up the heater controls are.

Pressing Heater OFF should turn off the blower after a few minutes. If the blower runs anytime the heater is powered then the relay in the Fenwal that controls the blower is probably welded closed.

@swamprat69 can take you through the voltages at the Fenwal that you should see during the startup sequence.

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Usnavy1610 said:
I should clarify. While the heater only turns on when the pump is turned on, appropriate delays are set up in the system. For example, when the spa function is turned off and the pump stops, the heater blower keeps blowing for an approximately a minute before the heater turns entirely off.
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When the pump stops, water flow stops, and the pressure switch opens which cuts the 24V power and shuts down the heater.

That does not indicate that the heater controls are functioning properly.
 
Well just take me out back and shoot me. First time I have worked on this at night and just now noticed that I have a 1 flash Every 3 seconds on the Fenwal Until the service light came on, it then extinguishes. I know I looked at that before, perhaps it was after the service light had already on? My apologies. I understand this means an airflow fault- is this related to the AFS LED on the back of the controller board? My apologies again.
 
Usually when the Fenwal gives the one flash LED the PCB will show the AFS fault.

It means the air flow switch is not getting enough air to close which tells the Fenwal to proceed with the start sequence.

Heater Flame Sensing - Further Reading

www.troublefreepool.com www.troublefreepool.com

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com www.troublefreepool.com

Fenwal LED Light​

The LED will flash on for 1/4 second, then off for 1/4 second during a fault condition. The pause between fault codes is 3 seconds. The LED light on the Fenwal box can indicate the following problems:

  • Steady on - Internal Control Failure
  • One flash - Air Flow fault
  • Two flashes indicates flame no call for heat, then the Fenwal is detecting a flame current when it shouldn't be
  • Three flashes indicates no flame current being sensed and ignition locked out
 

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JamesW said:
An Air Flow Fault can also be caused if the air flow switch is closed before the blower is on.
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Check with your multimeter if the air flow switch is open when the heater is off.

It seems the lightning strike welded a few relays and switches closed in your equipment.
 
If the blower is on before the heater control commands it on, it will close the air switch and the heater will interpret it as a bad switch because it does not know that the blower is on.

Check the circuit board in the Fenwal.

Possibly a stuck closed blower relay.

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Quick update. I measured the AFS switch this morning with power off and it was always open. I gave it a few taps with a screwdriver handle to possibly dislodge any welds. With the wires off, I turned the unit on and the AFS light quickly came on. I turned power back off and then tried to remove the tubes to test for air flow and make sure there weren’t any blockages, and managed to break off the black side nipple (I believe this is the output side) on the AFS, photo attached (sigh). Anyways, when I reconnected the wires, I restarted the unit from scratch with black side hose obviously off, to see what happens. Lo and behold, the heater ignited and Fenwal was not flashing, but after 30 or so seconds, the unit would make a rumbling sound and my filter pressure meter would jump around so I turned it off the heater. However, the blower is still always on even after several minutes. I am pushing 52 GPM through the heater, and the pressure is steady at 10 psi @ 52GPM when the heater is not on. In summary:

1. Fireman jumper on.
2. AFS white and black hose removed
3. Turn on main filter pump
4. Heater blower turns on immediately and stays on.
5. Turn on Spa Heat.
6. Unit immediately to goes to Service. AFS error light on, Fenwal flashing once very 3 secs.
7. Reattach black hose. Service, AFS, Fenwal lights go out.
8. Unit ignites after about 5 secs.
9. After 20 or secs, heater makes rumbling clanking sound, and filter pressure gauge starts to jump around.
10. Turn heater off, heater blower stays on.
11. Pool pressure normalizes.

Also, I couldn’t always produce ignition, the Fenwal would continue to flash every 3 secs and service light would stay on.

Haven’t had a chance to pull apart Fenwal but plan to do that tonight.

Thoughts?

SRM
 

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When the heater first turns on, the control board is looking for an Open Air Flow Switch.

When the control board tells the blower to run, it is looking for a Closed Air flow Switch.

If the blower is on when the control board is not telling the blower to be on, the control board assumes the blower is off and it expects to see an open air flow switch.

However, if the blower is actually on when the control board is not telling it to come on, the AFS will close and the control board will see a closed switch when it expects an open switch and this is causing the error.
 
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Usnavy1610 said:
Thanks for the feedback. First, correction on my original post. #4 should say "the unit does not ignite but the blower keeps BLOWING."

@JamesW- photo of box w/ ICM is attached. Any feedback appreciated. I will check out the link you sent.
@Srqpoolguy- From photo, fuse looks like it's not blown, but I will verify in the morning and also check on for voltage on control line coming from the EasyTouc. Just to confirm, if EasyTouch is not calling for heat, line should be 0V. Calling for heat, 24V. Is that VAC or VDC for that line?

I'm hoping that there is nothing bad with the EasyTouch control panel- the rest of the pool automation is working correctly.

Thanks SRM
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Vac. I would bet the control board on heater and keypad are gone. Your keypad if not lighting up will be hard to know what's going on. If you flip the lid over you may get codes at corresponding lights. May give you and idea. However I've seen these heaters do all kinds of weird things when the pcb goes out. Look for any burn marks. There are wing nuts under the lid. Loosen them and flip it over so you can see the control board under. It also only take a drop of rain to dry those keypads and boards. If replacing use a good seal ent around key pad. Number one rate if failure.... any rain with this lightning?
 
Usnavy1610 said:
but after 30 or so seconds, the unit would make a rumbling sound and my filter pressure meter would jump around so I turned it off the heater.
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Usnavy1610 said:
9. After 20 or secs, heater makes rumbling clanking sound, and filter pressure gauge starts to jump around.
Click to expand...
This is usually a flow issue, so maybe a bad internal bypass or thermal regulator.

Pull the thermal regulator and look for the internal bypass disc at the top of the regulator pipe hole where the thermal regulator goes.

Look into the inlet to see if the internal bypass looks ok.

Can you show the entire system?

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