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Baxi Ht 380 boiler gas pressure fault

bruce_21 Member Posts: 238
The last two times it got super cold, the boiler went off and gave a code indicating a gas pressure fault. Both times the air handler which is 75% of the heat load had been turned off. There was frost all over the outside gas regulator seen the second time, don't know about the first time. The gas company said that because the boiler was running flat out to make up the indoor temp that caused the gas pressure problem. Is this for real? How do the regulators work that a long time flow can reduce the pressure? What could be happening here?


  • meplumber
    meplumber Member Posts: 678
    Sounds like a vaporization problem.

    Is this natural gas or propane?
  • Tim McElwain
    Tim McElwain Member Posts: 4,588
    If this is Propane

    it could be that the liquid is not fully vaporizing. Propane gets down to very low pressures in the tank when the temperature goes down. The boiling point of Propane is -44 degrees but vaporization can be affected when temps get down near zero. One of the solutions is to make sure the line to the Baxi is at least 3/4" pipe and has a good 10 feet of uninterrupted pipe directly to the unit.

    The other thing to do is shield the second stage regulators as best you can from cold winds.

    If this is natural gas then I would be very surprised if that regulator is affected by running a long time. A solution to help eliminate the freezing problem on either is to place a tee with a drip leg and fill it with "Methanol" this will help to keep the lines and regulator from freezing up  The gas  company or propane company should be the ones to do this.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,253
    on Natural gas

    the only freezing issues I have seen were when the roof dripped on the regulator and froze the vents shut on it. Icicles and gas regulators are not good playmates. Tin roofs of sheet metal help out until the gutter guy can get in to divert the water.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
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