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boiler losing pressure?

B_Gee Member Posts: 1
Howdy folks....

  We have had call backs from three different clients(whose boiler systems we have installed), about their heating systems losing pressure.  The boilers are all Viessmann Vitodens. The pressure goes down to about 9 PSI and the systems shuts down. We boost it back up to around 20 PSi and everything works fine for about two weeks- then same thing happens again.  Could this be a problem with the PRV? Any suggestions>---Thanks.


  • Timco
    Timco Member Posts: 3,040

    I would get the system up to 25# exact, put a gauge on the system side, isolate the boiler, and see which side (system or boiler) drops pressure. At 25#, you should see something leak. Unless you see water under the PRV from a leak, not likely the issue, and the water has to be  going somewhere. Converted gravity with the attic tank vent still spilling out onto the roof?

    Just a guy running some pipes.
  • JK_3
    JK_3 Member Posts: 240
    I agree except

    I agree with timco except for if you are alreadt setting at 20 psi and drooping to 9 psi in two weeks it could take several hours do detect. I would a the max allowable pressure ( I beleive its 50 psi ) for the entire system and figure out which side is losing pressure. If neither side is losing cold I would then lower the pressure to 25 psi, fire the boiler to operating temp for a short time( watch the guage DO NOT LET IT EXCEED MAX PRESSURE) and then let it cool down, If the pressure ends up lower than 25 psi you may have a leak on or near the exchanger that only leaks when hot and the water is leaving with the flue gas. I have had this be the case more than once and the first time it took several call backs to figure out. Let us know what you find.
    Life is Good !! Enjoy it !!
  • CattivoAngelico
    CattivoAngelico Member Posts: 1
    In Need Of Serious Help!

    It seems that my water pressure is no longer what it used to be and it worries me greatly!  I have lived in this home for almost 5 years now and have never been low on water!  There are times now when my shower runs down to a trikle, there is a serious issue and I'm freakin out and my husband seems to think that oh its just an act of God to he** with that it's time to take matters into my own hands!!!! I need it fixed now before I am unable to live in a $220.000.00 home! I have a boiler system.  I do not use the heat in the summer.  I have a well about a 120ft. from the house.  There is a tank next to my water softner system and so far as I said 5 years now it has been wonderful! I do my usual routines wash, dishwasher, showers, and such so that hasn't changed!  It's getting frustrating and I'm not to keen on spending $500.00 on a plumber when I'm trying to play catch up for heating bills for the winter months!  If anyone on this planet can understand my pain and this crap that's happening with this supposed very EXPENSIVE house I bought I would really appreciate the help!

                                Signed Very Disappointed American Homeowner! 
  • Gordy
    Gordy Member Posts: 9,546
    edited July 2010
    You really need to have

    A professional check out your water supply system. There is a multitude of causes for the symptom you describe.

    I'm not a professional Plumber.

    It could be anything from the well needs to be deeper to a limed up shower head.

    With a well supply there are different components that can cause low water pressure.

    Could be the well pump.

    Could be the pressure Tank, or some of its components.

    Could be the water table is getting low.

    Could be debris in the supply piping plugging up the aeroators in your faucets.

    Sorry for your pain but these things can happen in a house that cost 100,000.00 or 1,000,000.00.
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