Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 18 of 18

Thread: Hayward h400 heater error

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Unhappy Hayward h400 heater error

    Ok guys, second thread post here, so take it easy on me.

    Tried to fire off my pool heater today but no luck. Hayward h400 with external automation control. Hit the heater button on panel but the display on actual heater has the following error codes:
    - Bo , which is normal according to manual if externally controlled.
    - SF - temperature sensor failure.
    - HS - water temperature exceeds 105. Don't think so as pool temp is 74F.
    - LO - water pressure switch, limit switch or vent pressure switch is open.

    Where do I begin?

    A few pieces of info:
    - natural gas line open.
    - automatic pilot switch system, so no manual lighting. Don't even here anything trying to come on at all or at least fire the burners.

    Any help would be appreciated on where to start. My pool boy doesn't do heaters!!!

  2. Back To Top    #2

    TFP Guide

    Join Date
    Jun 2012
    Location
    western NY
    Posts
    1,557

    Re: Hayward h400 heater error

    Do you have water flow to the heater? Check to make sure any bypass valves are positioned correctly. Once that is verified you may need to test each of the sensors that are causing the problem. Do you have and know how to use a volt/OHM meter?
    Unknown make 18' above ground (bought used in 1999) Sparco sand filter. Hayward 100,000 BTu heater. 2 speed pump

  3. Back To Top    #3

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Pump is on (variable speed - 2500 rpm) with water flow through heater. Minimum for this heater is 25 gpm so I assume pump is pushing enough flow. I even tried at max speed (3100 rpm) and still same result.

    The heater is installed after the DE filter and right before the return line back to pool.

    Very comfortable with voltmeter and have one handy. Will upload picture of the heater with cover off shortly.

  4. Back To Top    #4
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Hayward h400 heater error

    Have you tried the obvious?

    When I had error codes, I just killed the power to everything for ten minutes and it reset itself. It's fixed it twice over the last couple years.

    The next thing to look for is spider webs or rodent damage. Mice really seem to like the teaste of vinyl wire insulation.

    On my heater, first it checks for water flow, then it fires off the blower, and once it detects a draft, it opens the gas valve and starts trying to ignite. Spider webs in the air flow sensor will keep it from lighting.

    Let us know what you find!
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  5. Back To Top    #5

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    photo 3.jpgphoto 2.jpg

    Popped open the cover, cleaned all connections... still the same.. nothing fires off... looks in good shape on inside... here are pics.

  6. Back To Top    #6

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    That is a Hayward IDL2 heater. Not the best unit they made. Any way, it looks like you have a few issues or maybe just one, the control board.
    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,

  7. Back To Top    #7

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Thanks Paul. Problem is I can't even find someone that wants to work it. Most just want to replace with a new unit. Any idea where to begin troubleshooting? Control board error code isn't being displayed but maybe it is the issue?

  8. Back To Top    #8

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    Quote Originally Posted by Omarf4 View Post
    Thanks Paul. Problem is I can't even find someone that wants to work it. Most just want to replace with a new unit. Any idea where to begin troubleshooting? Control board error code isn't being displayed but maybe it is the issue?
    Check all of your wiring and connectors. I then would take it out of bypass mode so you can operate it at the heater. Then I would start checking out each error code. SF error is your temp sensor. You could get a new one and without actually installing it you can unplug the old one and then just plug the new one on and see if the error goes away.

    LO is possibly the pressure switch. First make sure you have good flow thru the heater and a clean filter. Then you could jump out the switch and if that error goes away, replace the switch.
    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,

  9. Back To Top    #9

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Hey gang, quick update here.....spent the morning cleaning all the connections and doing circuit tests with a multimeter. All checked out clear. After the hard reset, all error codes are gone and the heater actually fires up!,,, blower kicks in but a second later, I get the SF and HS error codes.....so I am back at the thermostat issue.....where the heck is the thermostat on this thing? It's the h400 IDL model, not the IDL2 model....this unit still has the dip switches for bypass operation vs the idl2 which doesn't.
    Help! Where is the thermostat?
    Note: I have automation with external panel that has air temp sensor and water temp sensor. The temp sensor is in the picture above attached to the outflow from DE filter into the h400 heater.

    Any help would be appreciated...I am very close to getting this thing working!

  10. Back To Top    #10

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    The right side header where the water flows in and out of. You will find the temp sensor there.
    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,

  11. Back To Top    #11

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Thanks Paul. Ok, have two of them. Top has purple and blue wires. Bottom has purple and red. Purple appears to just be a jumper between top and bottom sensors. So those need replacing? Both sensors?

  12. Back To Top    #12

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    No, those are the limits. OK check the other side then. It should have red/black wires going to it if it's the same that is used on the other Haywards.
    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,

  13. Back To Top    #13

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Thanks again Paul. Appreciated all the help. I found the thermistor on the other side as you noted. Black/red/blue wires twisted together and run from the control board over to the thermistor. But, here is where it gets interesting.....
    The way my h400 is wired, it's Setup for external thermostat connected to the terminal block to the right side of the transformer. So, I think we are now to either the remote thermostat isn't working or the thermistor needs replacement inside the h400 heater.
    Remote thermostat is reporting both air and water temp, which seems to be working as its displayed on the aqualink rs4 panel correctly. So I assume it's the thermistor that's faulted here........will see about ordering the part and hope to god I am on the right path.......
    If you have any other ideas to try, that would be appreciated.....thanks again!

  14. Back To Top    #14

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    It's the thermistor in the heater. The heater knows nothing about any other temp sensor external to itself.
    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,

  15. Back To Top    #15

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    YES it is!
    Listen to this guy's luck....I walk into Leslie's pool supply asking for the thermistor...he didn't have in stock but the store 45 minutes away did....so I take a gamble and drive over, pickup the $112 thermistor...bring it back, plug it in the control board without actually installing it into the inflow header...and guess what, the heater fired right up and heating the pool as I type this!!!!!! This issue is now officially RESOLVED!
    Will keep it hanging behind the control board for the day and then swapping it out at some point later...just don't want to deal with draining the heater for now....
    Paul, you my friend, are a ROCKSTAR...thanks for the help...will be sitting in the pool this evening having a cold on for you!

  16. Back To Top    #16

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,436

    Re: Hayward h400 heater error

    You don't have to drain the heater to install. Just turn the pump off and then disconnect the thermistor from the board and unscrew from the header. Install new on and then turn pump on.

    Glad I could help you resolve the issue. Hop you had a good holiday weekend.
    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,

  17. Back To Top    #17

    Re: Hayward h400 heater error

    For future reference, many times error codes and other issues can be resolved by simply pulling all the wires from the control board one plug at a time and re-seating them. This allows some of the oxidation to be rubbed off the control board pins. I've had luck with this many times over the years. Older units will have a higher instance of this problem for obvious reasons.

  18. Back To Top    #18

    Join Date
    May 2014
    Location
    Dallas, Texas
    Posts
    17

    Re: Hayward h400 heater error

    Thanks for the tip bugman, unfortunately, I had tried that at first with same outcome. It was definitely root caused as the thermistor with a successful replacement.

    Good tip though.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •