Max-E Therm SR400LP - Control Board LED doesn't come on

[1000RR]

I'm wondering if anyone has some troubleshooting suggestions on my pool heater (Max-E Therm SR400LP). It's about 3.5yrs old. I took a surge from an electrical storm and since then, the pool heater doesn't come on (the LCD screen on the heater shows nothing). Here are the things I've done so far:

• I've replaced the heater's control board w/new touch pad (Pentair replacement kit) - no change. Nothing shows up on the LCD screen.
• On the main Intellicenter, I've tested the output wires on the back of the main Control Board that says "Heater" and they are outputting a little over 27V.
• I've tested where the control wires that come into the heater at the glass fuse and get the same 27V.
• I've tested the yellow wire that comes from the heater's control board down to the Ignition Control Module and the input to the module is the same 27V.
• I've tested the 120V input to the Ignition Control Module and it has power.
• The Ignition Control Module has no LED light blinking
• When I flip the main breaker at the subpanel for the heater to ON, I immediately get 27V output at the heater output on the back of the main motherboard on the Intellicenter. If I tell the Intellicenter to turn on the Spa, the valves operate properly, and the light for "Heater" turns on in the Intellicenter but still nothing happens at the heater (heater LCD is still entirely off). And with the Heater indicating 'on' at the Intellicenter, I still get 27V.

So should I be seeing 27V all the time, regardless of what's going on (as my above bullets indicate)? What tells the LCD on the pool heater to turn on? Does the Iginition Module have anything to do with that part? The fact that I replaced the main control board and touch pad for the heater with a brand new one and there was no change should indicate that's no the problem. All other equipment works fine for the pool. With the electrical surge, I also had pool LEDs have issues, but I've replaced them and they're fine. Should the main control board at the Intellicenter vary the output voltage from 27V to something else when it receives the Spa On/Heater On signal?

Let me know if you have additional suggestions or if I've said enough you can suggest the issues (Heater's Ignition Control Module? Intellicenter's Main Control Board? Something?).

Thanks in advance!

 

[ajw22]

First thing to do is remove the heater from IntelliCenter control.

Go to the fireman’s switch connection in the heater and disconnect the control wire and wire nut the wires at the heater tog.

Show me a picture of what you found and what you did.

It should look like the picture above.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[1000RR]

@ajw22 Allen, thanks for your response. If I understand correctly, I'm going to disconnect the control wires coming in from the Intellicenter and then take the two yellow wires as part of the Fireman Switch and tie them together. After that, I can flip the main breaker back on for the heater. I'm suspecting that you'd expect to see the heater kick on at that point and be able to be controlled from the control panel on the heater if the heater is working fine at that point, yes? And if that's the case, you're going to tell me that I blew up part of the main control board in the Intellicenter, yes? I'm just guessin/anticipating....

 

[ajw22]

Just do it and let’s take it one step at a time.

I doubt you blew up your IntelliCenter board but let’s see which box the problem is in.

 

[1000RR]

@ajw22 Thanks Allen. When I tie the two yellow wires together from the Fireman Switch (where I disconnected the control wires for the Intelicenter), you said to take a picture of what I found. Are you wanting a picture of something in particular (LED screen, Ignition Module area, etc)? With the wires jumper'd like that, the heater should work on its own independently, correct. Basically work via the top touch pad? Let me know what you expect so I can be aware of what to look for. It's dark here now, so I'll get out there in the morning and let you know. Thanks again!

 

[ajw22]

I expect you to connect the wires together, show me a picture of the wiring area like I posted, and tell me what the heater control panel shows. Does the heater then work with the pump on?

 

[1000RR]

I expect you to connect the wires together, show me a picture of the wiring area like I posted, and tell me what the heater control panel shows. Does the heater then work with the pump on?

Sounds good Allen, I'll report back tomorrow morning once I get back out there. I'll let you know. Thanks again!

 

[1000RR]

@ajw22 Hey Allen, I jumper'd the wires as suggested. The Control Board now comes on. When adjusting the heat upward on the touch pad (w/pool pump on high) to engage the heater, the red heater LED on the touch pad comes on for a moment and then goes out, and then I get an Error Code on the LCD display of "ERR AFS". The LED on the FENWAL shortly there after comes on blinking once every 3s also indicating an Airflow fault. If I have the Fireman Switch wired back into the Intellicenter, I get nothing again at the LCD Touchpad (LCD Screen doesn't power up).

 

[ajw22]

You have multiple problems.

Does the blower begin running before the heater throws the AFS fault?

Does your heater have a 5 button control panel or 6 buttons?

On your IntelliCenter open the top compartment with the PCB. Find the gas heater relay the fireman’s switch is connected to. Disconnect the wire from the relay use your multimeter and check for continuity on the relay screws when you call for heat .

 

[1000RR]

I had a feeling it was multiple issues.

Blower does not begin running before heater throws the AFS Fault.

Heater has the 6 button control panel

When performing the continuity test at the heater relay on the Intellicenter (with wires removed), there is NO continuity when I call for heat (heater light comes on, on the Intellicenter panel after I make the call for heat, but the relay is still open, no continuity).

 

[ajw22]

Is everything else working properly on your IntelliCenter? If so let’s leave your IntelliCenter alone until you have a working heater to reconnect to it.

I suspect the the gas heater relay or relay driver was fried. But with your heater you can use RS-485 control instead of the fireman’s switch.

Back to the heater - The blower is powered through the Fenwal F1/F2 connections that are a relay. Disconnect the wires to F1 and F2 and safe them off. Check if there is no continuity between F1 and F2 when the heater is off and that there is continuity when you start the heater. That would show the relay in the Fenwal is working.

I suspect the lightning hit close to the fireman’s switch wire and blew out the relay on your IntelliCenter board and maybe the relay in the Fenwal controlling the blower.

 

[ajw22]

As a further check of the Fenwal…

The F1/F2 contacts on the Fenwal are supposed to close and start the blower motor when you have 24 volts between "TH" and the 24 volt ground. If you have 24 volts at these 2 points and the F1/F2 contacts do not close, you would need to replace the Fenwal.

Check for 24V between TH and ground when the heater starts up.

 

[1000RR]

Everything else is working properly on the IntelliCenter - yes.

F1 & F2 disconnected, manually called for heat on the Heater's Control Pad, Heater LED on Control Pad lit for a couple/few seconds, no continuity between F1 & F2.

 

[ajw22]

Check for 24V between TH and ground when the heater starts up.

 

[1000RR]

As a further check of the Fenwal…

The F1/F2 contacts on the Fenwal are supposed to close and start the blower motor when you have 24 volts between "TH" and the 24 volt ground. If you have 24 volts at these 2 points and the F1/F2 contacts do not close, you would need to replace the Fenwal.

Check for 24V between TH and ground when the heater starts up.

I tested voltage between TH and Grnd when I called for heat (Heat LED on Control Panel lit for a couple seconds) and ZERO voltage. Still confirmed to have ~27.3v at Fireman Switch.

 

[ajw22]

Did you replace your heater board with a genuine Pentair board?

You say you replaced the keypad also. Did your old keypad have 5 buttons or 6 buttons?

 

[1000RR]

Yes, replaced heater board with genuine Pentair replacement kit.

The old one had 5 buttons. The new one has 6 buttons. When it turns on it says Version 2. I still have the old board/touchpad.

 

[ajw22]

Below is the wiring diagram.

TH voltage comes from the PCB that you say you replaced to the Fenwal to tell it to turn on the air blower.

 

[ajw22]

Yes, replaced heater board with genuine Pentair replacement kit.

The old one had 5 buttons. The new one has 6 buttons. When it turns on it says Version 2. I still have the old board/touchpad.

Ok, then you don’t have the ability for RS-485 control of the heater which complicates your IntelliCenter repair if you get this heater running.

 

[1000RR]

I checked for voltage on the Fenwal side at TH, not the yellow/blue tracer wire itself. Should I test the Yellow wire instead?