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No pressure reducing valve

DavidMitten Member Posts: 16
A friend of mine with hydronic heating system had a no-heat problem. The issue seemed to be a low water condition in a few of the zones. I filled the system through the purge valves and bled the air.
Here is what I don't understand - there is no pressure reducing valve/backflow preventer for boiler makeup water. The only way to put water into the system is thru the zone purge valves with a garden hose. The boiler does have an LWCO, so I am not worried about that bit.
The water is supplied by well. Does this have anything to do with the setup? Her ex-husband(plumber) installed the system, but the circulator pump is in the wrong place, so I question what his knowledge base was.
Unfortunately, I am on not on the east coast, where people know what a real heating system is. So, I have few personal resources nearby to consult.


  • hot_rod
    hot_rod Member Posts: 22,271
    It's best to have a fill valve and approved backflow valve, or one of the plastic fill tanks like Axoim.
    If it has glycol, you need to use a fill tank and not connect it to the potable water.
    A low water cutoff valve is also a good idea.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • WMno57
    WMno57 Member Posts: 1,348
    edited January 2021
    My 70 year old boiler has no LWCO, BFP, and the circ pump is in the "wrong" place. The PRV cuts off at 22 psi. I fill to 12 psi and shut off the water, so my PRV might as well not be there. It all works just dandy.

    I also only have one zone.

    Is the well water extremely hard or high iron? Maybe the system was initially filled with better quality water? Other than that, I don't see why being on a well would make a difference in how it should be set up.

    How about a photo of the system, or at least tell us more about it.
    I DIY.
  • DavidMitten
    DavidMitten Member Posts: 16
    It does have a LWCO.
    It is not a Glycol system.
    I would think that just for homeowner convenience, and ease of use, it would have a proper fill valve.
    Otherwise, someone has to fill the system upon startup each season, and for a homeowner who is not a heating enthusiast, that is just a hassle.
    I will post some pictures, but I think my question is answered.
    Looks like I will be working on the whole system as soon as the season is over.
    HVACNUT Member Posts: 5,865
    I've seen a few water boilers where they forgot to install a drain in or at the block, but I don't think I've ever seen one without a means to fill. Even without a PRV.
    Follow all the piping. You might find something, even just a manual valve. Any valves turned off at the well pump or X tank?
  • HomerJSmith
    HomerJSmith Member Posts: 2,468
    edited January 2021
    The water fill (supply) pipe doesn't go directly to a valve on the expansion tank, does it? What does the tridicator gauge say the sys pressure is?

    Well water is iffy. I never use it. One can test it at Rhomar's site by sending a sample in. Then you will know its quality.

    Pics would help in the analysis. Why would you say the pump is in the wrong place?
  • Big Ed_4
    Big Ed_4 Member Posts: 2,807
    Does the expansion tank looks like this with a cool water pipe to it ?

    There was an error rendering this rich post.

    EBEBRATT-Ed Member Posts: 15,635

    I agree it should have a reducing valve.

    But hot water systems don't use water. I have installed many a glycol system with out any water line connected to it and they run for years without adding and water or antifreez. You don't need to add water every year unless you have a leak.