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Is this fixable?

lauranyclauranyc Posts: 3Member
We recently bought a house that had been renovated in the 90's.  It is a 4 zone hydroponic water baseboard system.  We've noticed that the thermostats do not seem to control the heat very well.  I replaced all the thermostats and the problem persisted.  After some careful testing, I think I know what is going on. 

When zone 1 is firing up, all the other zones' radiators seem to get hot too.  In the basement, the control panel shows only zone 1 lit up and only the zone 1 pipe that is connected to the control panel gets hot.  So far, so good.  However, I have noticed that there are another four pipes behind those going back into the boiler.  All four of those pipes get hot.

So, it seems like the thermostats are working and the control panels/valves are ok, but somewhere in the house, the zones get merged together.  Is there any way to fix this?  A diagram of how I think it is supposed to work is attached.   All the pipes represented in the lower right corner get hot when only one zone is on.


  • Jamie HallJamie Hall Posts: 8,381Member
    Well, the diagram

    is a decent representation of at least one of many ways these things can be hooked up.  However, it does sound as though somewhere in the system there is (are) valves which shouldn't be open, or cross connections between zones.

    I'm afraid that what you are going to have to do is start tracing pipes, very carefully.  Then, if you don't find something obvious, make a careful sketch of exactly what you have traced out and post that and we'll see what we can make of it.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • STEVEusaPASTEVEusaPA Posts: 2,089Member

    Can you post some pics? It appears you may have some themosiphoning. You feel heat in the return piping. How far away from the boiler, following the pipes in the non calling zones, do the pipes feel hot? Besides checking all the wiring/components, you may need some flo-cheks.

    On a general note, a hydronics pro to check the entire system may help with your inadequate heating complaints.
  • heatpro02920heatpro02920 Posts: 991Member
    Check valves?

    I have a hard time picturing all the zones being tied together in the house somewhere, it is more likely not the issue, someone would have had to go through a lot of trouble and materials to do it wrong, I have seen crazier things, but unlikely its the case..

    Where are your check valves and are they functioning properly?

    I agree with Steve pics would be very helpful...
  • JohnNYJohnNY Posts: 1,988Member
    "Hydroponic". Lol!

    I'm sorry but I have to laugh. The word you're looking for is hydronic. I think hydroponic is the method used for growing pot plants in a closet.

    There is very likely a simple fix to the problem in your system. Where are you in NYC?

    Perhaps I could have a look. On the house. My contact info is below.
    For private consulting services, find John "JohnNY" Cataneo here at :
    "Heat Advisory, LLC"
    Or email John at [email protected]
    John is a professional Master Plumber by trade, licensed by The Department of Buildings of The City of New York, but travels regularly to out-of-state clients for consulting work.
  • billtwocasebilltwocase Posts: 2,385Member
    first thing I see

    if your diagram is correct, the relief valve shoud be on the boiler, and not the heat supply, especially where you can isolate it from the boiler by closing supply and return valves. Seems like what others have said, you have bad or open flow checks. Pics would be better 
  • psb75psb75 Posts: 58Member
    a "certain radiant design co"

    Just a heads up: I live and work in VT. This drawing format is recognizable as being from a "certain radiant floor design co. in VT" that caters to DIYers. Also notice that it does not say "boiler" in the diag., rather it is labelled "water heater." Lucky, at least it is labelled "closed system."
  • lauranyclauranyc Posts: 3Member
    Thanks for the responses and yes, that is not an actual

    diagram of my home.  We just moved in and I grabbed something off the internet that best looked like my system.  We have a furnace/boiler heating everything, not a water heater.  I'm not really sure if it is considered open or closed, but I thought the home inspector said closed.  As JohnNY pointed out, I really don't know much about heating systems.  Hydonic/Hydroponic... sounds pretty much the same to me.  :)

    How do you guys go about tracing pipes?  Everything disappears behind walls right above the furnace.  I had one company come in to do routine maintenance on the system and they said they couldn't help me without opening up all the walls.  Is that right?

  • lauranyclauranyc Posts: 3Member

    I would love for you to come take a look.  I'll give you a call today.

  • icesailoricesailor Posts: 7,265Member

    Anything is fixable.

    Post photos of the boiler and the near piping. Show the "control box" with the lights. Is it green or grey?

    I doubt that it was this way when it was new. There are a lot of ways to figure this out. The last ones there didn't want to try. If they ripped open the walls, what did they think they would find? You need a REAL Professional Wethead to look at it.

    You're the only person that has posted your problem so obviously, the last person looking at it doesn't get educated at See if someone here lives or works near you. You won't regret it.

    Some of us here have never seen anything we couldn't figure out with time. Some of us have never seen anything that we couldn't fix. Some others out there could care less as long as they were in their vehicle at quitting time and headed to the local watering hole to get their medication. Or the boss isn't screaming because they didn't get the 8 service calls done for the day. There's no time allotted for your problem if it takes more than 1 hour to figure out and fix.
  • SnowmeltSnowmelt Posts: 918Member

    I hope Johnny comes over take some pics and tell us what's happening.
  • MacMac Posts: 13Member
    I believe the thermostats could be wired wrong

    as a possible cause of this.  I've seen where two thermostats were wired to the same two zone valves, so if either thermostat called for heat, both zone valves would open.  The third zone was wired properly and opened only when it was supposed to.  Correcting the wiring problem at the zone valves fixed the problem.
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