Max-E-Therm - "service Heater" Message

[peterstb]

Hi All,

I have recently been having issues with my Starite Max-E-Therm heater (model no. SR400NA). I have been trying to follow the trouble-shooting steps in the installation/owners manual, to no avail.

The Symptom:

• Turn the heater on Pool "or" Spa, and bump the temperature setting to a few degrees above the standing temperature
• "Service Heater" light comes on for a second, then goes off
• Blower is running, but no ignition attempt is made
• After 20 or so seconds, the "Service Heater" light comes on permanently. (Requires the heater to be turned off, as decreasing the temperature is not possible in this state)

Troubleshooting:

• Turned over the control board to look for LED's possibly indicating an error (none on initial investigation, except for the "Service Heater" LED)
• Initiated the startup sequence again, and observed the LED's through the process
  • The AFS light comes on for a second, immediately on startup, but goes off again (result is "Service Heater" error again)
• Disconnected the two blue wires from the AFS switch and initiated the startup sequence again, and observed the LED's through the process
  • The AFS light comes on for a second, immediately on startup, but goes off again (result is "Service Heater" error again)
• Jumpered the two blue wires together (thinking I was bypassing the switch)
  • No AFS light this time, but same result ("Service Heater" error again)

• Jumpered the AFS switch terminals(Not sure why I did this??? :-))

  • The AFS light comes on for a second, immediately on startup, but goes off again (result is "Service Heater" error again)

I have disconnected the Heater power several times, throughout this process, per the troubleshooting guide, but it didn't seem to change any results.

Any thoughts would be greatly appreciated!

Best Regards,

Todd

[Pool Clown]

Do you hear the gas valve click while the blower is running?

[ps0303]

Possibly that the ignitor isn't glowing. Two ways to check it would be to turn the unit on and while it's going thru the sequences feel down around where the ignitor is and see if it's getting hot. Be careful as it gets REALLY hot. Or if you have one of the clamp on amp probes, you can see if there is any activity going on with that clamped around the wires to the ignitor.

[Shawn Hatfield]

I’m having the same issue but at the end the  ps led was lit up. I replaced the pressure switch but now it’s an afs on and off led and a service system led did you ever find the problem on your heater?

[DSG]

I have similar issues on my Sta rite max e. 
it has been working normally for years.  Now it initiates the fan, ignitor and burner normally, but shuts down after about 5 min.  The blower runs for a few minutes then turns off, with a Service Heater light. The board shows an AGS LED.  There are no LEDs displayed on the Fenwal board. I have replaced the AGS (twice) and all the other sensors and internal bypass valve and thermostat. The water pressure switch is functioning normally.  Basically everything.  The water flow is excellent and the filters are all clean.  I don’t see any obstructions in the burner inlet. 

Frustrating!! Can anyone suggest additional diagnostics?
Thx!!!