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Three zones into one

mistertee Member Posts: 2
edited July 2016 in Plumbing
I'm trying to eliminate some zones and clean up some plumbing.

Baseboard. heat only. (hot water heater is electric)

Old system:
Oil fired boiler
3 Zones. (three pipe manifold)
1 Zone Valve one one pipe. 1 Thermostat (main house)
Zone 2 and Zone 3 do not have a valve and are always open for water flow.
1 circulator pump.

An addition was added to the house, so when rooms were added, they just added the baseboard plumbing as a new stem off of the manifold.

When the thermostat calls for heat in Zone 1, that's enough heat for the other two zones, so they are not controlled by thermostats.

zone 1 original.
zone 2, added bedroom.
zone 3 added bedroom.
no need for thermostats in added rooms.

New system. Weil Mclain GV90+4

Goal: 1 zone. 1 thermostat.

Because only one thermostat for the house is really necessary, should there still even be a manifold OR should all of the baseboards be plumbed together to eliminate the manifold?

Because of the system and this is single zone now - No zone valve is needed. No zone relay is needed. No added circulator is needed - correct?



  • hot_rod
    hot_rod Member Posts: 21,898
    You probably would not pipe them In a series loop, manifold them as parallel circuits with valves to adjust flow and balance outputs.

    You can also regulate output in the rooms if the dampers are moveable on the baseboards
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mistertee
    mistertee Member Posts: 2
    hot rod said:

    You probably would not pipe them In a series loop,

    Thanks for the reply. I am by no means doubting the response, ..just asking so I can be more educated- Is there a reason why not to pipe them in with the loop for the rest of the house on the main zone 1?

    To help illustrate this better.
    Bedroom A was there when the house was built and controlled by the thermostat, in the loop with the remainder of the house.
    Bedroom B and Bedroom C were added on later on next to it.

    Bedroom B is pipe 2 off of the manifold.
    Bedroom C is pipe 3 off of the manifold.

    Why couldn't or shouldn't Bedroom B & C be added into the loop instead of creating/keeping the manifold?
  • Jamie Hall
    Jamie Hall Member Posts: 22,972
    The reason is to control the temperature drop in the loop. Longer loops -- such as adding zone 2 and zone 3 in series with the first zone -- means either a need for much higher flow rates through the new, long zone, or tolerating a much greater temperature drop, which means the zone at the end won't get as much heat.

    You are much much better off to have one circulator feeding the manifold, and have flow control valves on the manifold to balance the three zones the way you like them. Simpler, too, since that's where the piping goes now...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England