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Thread: Heater not turning on

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    Heater not turning on

    My Hayward heater won't turn, is displaying a LO service code and won't get out of bypass mode. I have found the following troubleshooting tip but I don't know how to fix the problem.

    Thanks!!!

    The display will continue to show “bo” for 10 seconds, then “LO” will be displayed again.
    a. If the remote thermostat does not generate a call for heat the “LO” error will continue to be a “soft” lockout. The control will accept keypad inputs to change the mode and it will remain in the selected mode when the error code is cleared. The heater will not operate until the error code is cleared.
    b. If the remote thermostat generates a call for heat the “LO” error will be a “hard” lockout. The control will accept keypad inputs to change the mode and it will remain in the selected mode when the error code is cleared or the call for heat is removed. It will not be possible to switch out of Bypass Operation until the error code is cleared.
    Houston
    ~20,000 inground plaster pool
    1.5 HP Hayward
    Sand Filter

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    Re: Hester not turning on

    "LO" can also indicate poor water flow, temperature limiter error, or, the communication wire between the heater and controller is shorted.

    Which model Hayward is it that you have?
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

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    Re: Hester not turning on

    H series 400k BTU

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    Re: Hester not turning on

    So it's the ED2 series. You could try jumping out the pressure switch. If "LO" remains, then check the limit switches. If that isn't it, then I suspect the comm wire between the heater and the control unit has an issue.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

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    Re: Hester not turning on

    Make sure the filter is clean. LO I have found is most likely a dirty filter.
    Hayward Pool Tech
    80+ Years of Technologically Advanced Pool Product Manufacturing
    poolside@haywardnet.com

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    Re: Heater not turning on

    First, it is a HDF unit. Don't know if that makes a difference.

    The filter is clean.

    I tried jumping the 2 limit switches with no luck. I'll try the comm wire next. Is there anything special about that?

    As a side note, when I pull the connector for the temp sensor the blower will turn on and then the unit throws a SF error code.

    I talked to a pool guy, he immediately went to getting a new control board.

    Thanks again!

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    Re: Heater not turning on

    You mean FD unit?

    Yes if you pull the temp sensor wire it will put out a SF error. It's supposed to.

    Removing the comm wire will allow the unit to operate independently from the control system. You would also need to take the heater out of bypass operation. You can find this in the manual.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

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    Re: Heater not turning on

    Thanks for all your help!!! I replaced the comm wire and everything is working again.

    A few hours of my time is much better than the $700 control panel the pool guy wanted to hit me with.
    Houston
    ~20,000 inground plaster pool
    1.5 HP Hayward
    Sand Filter

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    Re: Heater not turning on

    Glad you were able to get it running again.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

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