Heater fires up for a few minutes and shuts off

rich6429

Well-known member
Nov 25, 2021
110
Canada
Pool Size
30000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-20
Pool temp stayed low so I had took a look at the heater (Pentair Mastertemp 200). I noticed it had E05 error, and automatically assumed it was the Stack Flue Sensor since it is what Google tells me :).

HOwever, after powering off and then powering on the heater, I noticed that the panel showed ERR AFS and fired back up...heating water ('heating' light was on) and turned off after a few 2 mins.

It does not look like E05 is on the panel anymore, but everytime I restart, same error (AFS) now shows up...fires up and turns off.

outside of contacting a technician, which can take days, what are my options here or what should I look at?
 
When you say fires up - does the heater ignite? Do you get a puff of heat before the AFS errors?

When does the AFS occur? Does the blower start running?
 
When you say fires up - does the heater ignite? Do you get a puff of heat before the AFS errors?

When does the AFS occur? Does the blower start running?
When it stops running, I turn the heater off. When turning on, this is what the panel says (pic attached) quickly and disappears. Heater would fire and ignites. “Heating” light is also on. After a few mins, it shuts down.
 

Attachments

  • IMG_7789.jpeg
    IMG_7789.jpeg
    566.2 KB · Views: 9
When it stops running, I turn the heater off. When turning on, this is what the panel says (pic attached) quickly and disappears. Heater would fire and ignites. “Heating” light is also on. After a few mins, it shuts down.

What does the heater display show when it shuts down?
 
E05 error
Ignore the AFS message and fix the E05 error.

There are increasing reports of stack flue sensors failing on MasterTemp heaters 1 to 10 years old.

When the heater starts go to MENU - SFS TEMP to display the exhaust temp. Normal temps should be ~290-350.

The sensor may be tested with an ohm meter (3.8 MegOhms @ 77F),

See Pentair MasterTemp Heaters - Further Reading
 
Ignore the AFS message and fix the E05 error.

There are increasing reports of stack flue sensors failing on MasterTemp heaters 1 to 10 years old.

When the heater starts go to MENU - SFS TEMP to display the exhaust temp. Normal temps should be ~290-350.

The sensor may be tested with an ohm meter (3.8 MegOhms @ 77F),

See Pentair MasterTemp Heaters - Further Reading
I did display the SFS temp…and it was going from the 100’s to around 350…then would all of a sudden change to 40 and stay there. And then it turns off.
 
I did display the SFS temp…and it was going from the 100’s to around 350…then would all of a sudden change to 40 and stay there. And then it turns off.
You read the link I gave you above?

If the SFS reads 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor.

Try reseating the connectors on the SFS.

Otherwise it's a bad sensor or damaged wires.

If the sensor and wiring are good, the board is probably bad.

Disconnect the sensor and check continuity across its terminals.

Resistance should be 3.5-4.0 megaohms.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You read the link I gave you above?

If the SFS reads 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor.

Try reseating the connectors on the SFS.

Otherwise it's a bad sensor or damaged wires.

If the sensor and wiring are good, the board is probably bad.

Disconnect the sensor and check continuity across its terminals.

Resistance should be 3.5-4.0 megaohms.
To close the loop on this topic...issue was the stack flue sensor. I did disconnect and tested resistance. It wasnt registering any in my meter. But the heater continued to worked intermittently, so continued to use it. I just had to power off and power on to restart.

I ended up calling Pentair (since it is within 2 years) and the technician that took a look replaced the stack flue sensor and all is good again. Thanks for all your help.
 

 
Last edited:
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.