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Carlin EZ4 odd behavior when shutting down

wobano Member Posts: 8
Greetings. I have a Carlin EZ-1HPW burner attached to a Weil-McClain GO-4 boiler (tankless).

Recently, after a burn cycle (normal cycle - no issue there), the burner has trouble shutting down. I'm not talking about ignition - she lights up fine and the boiler runs for a few minutes. But, when the boiler shuts off, and burner USED to blow the fan for a few moments and shut off clean. NOW it tries to shut the fan off, but the fan pops right back on again.

The fan continues this cycling on and off and on very quickly for about 20 seconds...then stays on for a long moment (like 8 seconds), then finally shuts off completely. This pattern repeats every time: 1st attempt to shut down...then cycling rapidly on/off/on/off (less than a second each cycle), then a longer period "on," then finally shutting down.



  • BDR529
    BDR529 Member Posts: 273
    Has the control been changed? Verify B1 from the aquastat to control on the burner. the red and black wires get swapped sometimes in the clip I forget the name of.

    -I'll take a stab at wiring issue, cranky crontrol and or aquastat.
  • 426hemi
    426hemi Member Posts: 80
    What primary control do you have? 
  • wobano
    wobano Member Posts: 8
    What is a primary control? You mean Aquastat? My Aquastat is a Honeywell model L8124A1015
    B1 from Aquastat has not been touched or re-wired since before when everything was working well.

    I have a Weil McClain Boiler, GO-4
    I have a Carlin EZ-1HPW Burner
    Attached to the burner there is a fan housing (or something) that says "Beckett model no. 7Q7502."

    Thanks so far!
  • BDR529
    BDR529 Member Posts: 273
    Primary is on the burner, has the reset button.

    The line from the honeywell to the primary has quick disconnect for the electrical. The wires inside do not follow through correctly. That quick disconnect is always guilty till I prove it.

    If the Primary has been replaced,The black B1 from the Honeywell might end up as a red down at the Primary.

  • mattmia2
    mattmia2 Member Posts: 8,886
    perhaps the primary control uses a separate relay to run the burner motor when firing vs when in pre/post purge?
  • wobano
    wobano Member Posts: 8
    Carlin 60200-02 in my primary controller.

    It has been working "fine" for years until just recently - so wouldn't that rule out a miswire? Failing wiring, thou, I suppose makes sense. Can I open up the primary to see? Or just swap with a new one?
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,761
    The Carlin 60200-02 is the device that turns the ignition, valve, and motor on and off. The motor on and off is coming from that control. I would change the 60200-02 with the most recent replacement. Carlin 70200 has more diagnostic features

    Program the control for the features you need for the WM WTGO boiler.

    If you are not comfortable with DYI then get a pro to do it. You may benefit from a pre-purge and post-purge feature. Any burner adjustment should include a combustion test with instruments.

    Best wishes

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • mattmia2
    mattmia2 Member Posts: 8,886
    Maybe the relay for the burner motor is failing and it isn't shutting down but is experiencing ignition failure. Or any number of connections may be burned and intermittent or melted and shorting.