1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Setting radiators without TRVs (room thermostat)

Discussion in 'Home and Garden' started by Richie, 20 Oct 2021.

  1. Richie


    Joined: 18 Oct 2002

    Posts: 7,781

    Location: 7th Level of Hell...

    I'm hoping there are people in the know here.

    My home has 2 thermostats.

    Living room controls the while house including upstairs with the exception of the main bedroom.

    Main bedroom thermostat controls only main bedroom.

    Now the radiators in the living room and bedroom do not have TRVs as the room stat would control them.

    Given there is no balancing issue for the bedroom side (as it's 1 rad on its own circuit) should the lock valves on the radiator in the bedroom be fully open or would this affect the efficiency because the water leaves the rad at a rate that is too quick?

    Is it better to have the input side fully open and the return side closed down a bit? (advice I have seen so far is to have circa 12oC difference between input and output ffor effective heat flow)

    Hope this all makes sense as to what I am asking
  2. Simon42


    Joined: 11 Dec 2006

    Posts: 761

    Although it's two circuits, if these are supplied from one primary loop which would be the norm in most houses, then you need to consider the balancing when both circuits are calling for heat due to their thermostats and not just one or the other (unless times prevent overlap).

    If the single room circuit has full flow then it could deprive the other rads depending on the pipework layout, so you should balance the whole system as if every rad needs heat.
  3. Richie


    Joined: 18 Oct 2002

    Posts: 7,781

    Location: 7th Level of Hell...

    Makes sense. I do have them on differing schedules so they shouldn't overlap.

    I am concerned that having both fully open would be inefficient as the water would be too hot as it left to go back to the boiler (condensing type)
  4. LuckyBenski


    Joined: 28 Dec 2017

    Posts: 6,003

    Location: London

    Are you asking about the valves on either side of a single radiator? In that case it doesn't make much difference how you achieve your desired flow rate. The flow into the radiator is equal to the flow out of it. Water can't leave the radiator faster than it goes in, so any restriction will have the same effect.
  5. mickyflinn


    Joined: 23 Mar 2011

    Posts: 13,033

    Location: West Side

    The return usually is the valve you balance the complete system so radiators upstairs i usually open one turn then this forces water to the radiators downstairs which are open fully. Returning water from downstairs takes more effort on the pimp so valves are open more. If your on a single floor property furthest rad would be open more .Hence the system is balanced but there may be a bit slight variations to how much each valve are open.