Forum Discussion

Knoffsinger's avatar
Knoffsinger
Explorer
Apr 15, 2019

Water heater circuit board

We are in a 2000 Komfort fifth wheel and our water heater quit working today out of the blue. The breaker was flipped and we flipped it back but the hot water is still not working. We noticed that the circuit board (35-525900-113) looks possibly fried. We've only used it on electric, not on gas. A few of the diodes also are loose or falling off. Is the circuit board only for when your on gas? Is there somewhere we can buy another circuit board? Is there anything else we can try before going out and buying a new water heater? We are in our fifth wheel full time so it's super important for us to fix this ASAP.
  • OP might need a new circuit board .....for propane usage



    NOT for the electric element use
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    enblethen wrote:
    Make and model of water heater?
    Breaker is for 120 volt option if equipped.
    Needs 12 volts DC on most to operate.
    Quick search shows you have a Suburban. Circuit board is easily available from Dinosaur electronics via Amazon.
    Circuit board
    Dinosaur Electronics


    I second the Dinosaurelectroics link..

    When my Water heater needed a new board I did not have the time to order so I went with an OEM

    But for my furnace I went with Dino boards.. I'm a trained electronics tech and the first thing I noticed was the QUALITY of the board.. (Way better than OEM) the next was.

    Well as an electronic Tech I have a theory as to what killed the OEM board.. Turns out Dino shares that theory because they put a protective device on the board to prevent it from happening again.
  • Suburban Water Heaters use 'separate' systems for electric and propane.
    Circuit Board controls propane ONLY (except for DEL models)

    Electric system
    120V AC Circuit breaker AC Junction Box on backside of WH TANK (right side looking from the back)
    From Junction Box to on/off switch (OEM in outside compartment lower left corner)
    From On/Off switch to Hi temp t-stat to normal temp t-stat (under cover above gas valve---Hi temp is resettable Left 'Push to Reset' button)
    From t-stat to element (under cover below/behind gas valve)


    120V AC Circuit Breaker tripping...element most likely shorted/burnt out.

    Break out voltmeter and trace the 120V AC circuit to Junction Box ---to element

    Do a continuity test on element
    Disconnect the wires (Black/White from element)
    Check for continuity between the Black & White element terminals
    No Continuity...element bad

    Check for continuity between White terminal and element flange
    Got continuity...element shorted

    New elements available at most any 'big box' hardware store
    120V AC 1440W element


  • Make and model of water heater?
    Breaker is for 120 volt option if equipped.
    Needs 12 volts DC on most to operate.
    Quick search shows you have a Suburban. Circuit board is easily available from Dinosaur electronics via Amazon.
    Circuit board
    Dinosaur Electronics