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pressure relief on tankless keeps lesking been replaced twice is

k bm
k bm Member Posts: 1
I have a job that the pressure relief keeps blowing off on the tankless. it has been replace but leaks the next dat. it is 15000 btu rated at 150 psi what the heck?

Comments

  • JERRY   MAC     HODGE
    JERRY MAC HODGE Member Posts: 1
    TANKLESS P/R BLOWING

    CHECK OUTSIDE WATER PRESSURE, MAY NEED THERMAL EXPANSION TANK, IF THERE IS A CHECK VALVE IN THE COLD WATER SUPPLY IT WILL CAUSE THE WATER TO EXPLAND THIS SHOULD NOT BE A PROMLEM WITH TANKLESS HEATERS AS THE WATER IS FLOWING WHEN IT'S ON.
    CITY WATER PRESSURE COULD BE GOING UP BY 15 TO 20 PSI. AT NIGHT CAUSING THE RELIEF TO BLOW, THEN YOU NEED A PRESSURE
    REDUCING VALVE INSTALLED ON HOUSE SYSTEM, NOTE MOST PLUMBING CODES LIMIT CITY PRESSURE AT 80 PSI.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Expansion Tank?

    If thermal expansion is the cause, no relief valve will hold back that kind of pressure. Is there a check valve in the system to the tank inlet and if so is a potable-water rated expansion tank installed?

    Boyles Law, (S.370, 1662 Acts of God, Supra)
  • Greig_2
    Greig_2 Member Posts: 5
    pop-off

This discussion has been closed.