Radiators cold downstairs, hot upstairs

Discussion in 'Plumbers' Talk' started by Mardanis, Dec 28, 2020.

  1. Mardanis

    Mardanis New Member

    Hi,

    I have a 3bd house, there are 4 radiators upstairs and 4 downstairs. The boiler is a Worchester (I'll update with model later) and the system was disconnected with the house in renovation for over a year. A heating engineer came out and commissioned the system, signed it off and left idle for a few months.

    I've finally gotten back home, found the water pressure was at zero. Refilled the system, bled each radiator at the bleed points and fired up the boiler after replacing the batteries to the thermostat (it reported low battery).

    The upstairs radiators get hot enough you don't want to touch them, downstairs is stone cold. the supply lines to downstairs get hot but the radiators do not. So I've checked all the valves both ends, they all function then bled/flushed all the lines where points are available to do so. I can pull hot water through via draining but it won't keep hot water circulating into them. The pump is set to 3 and feels like it is operating.

    I tried closing all the valves to upstairs and downstairs then open the valves on each radiator downstairs. 2 radiators are hot, 3 warm, 4th open then luke warm. I did try closing in the 4th and opening a radiator upstairs, the upstairs one was roasting hot and the downstairs 3 open barely held warmth.

    Any ideas please? This is driving me nuts.
     
  2. John the plumber31

    John the plumber31 Active Member

    They just need balancing
     
    Mardanis likes this.
  3. Severntrent

    Severntrent Screwfix Select

    If he means that he closed all the upstairs radiators and opened each downstairs radiator individually one at a time and still did not get them hot then its not balancing thats the issues
     
  4. John the plumber31

    John the plumber31 Active Member

    I
    He said after doing that 2 rads got hot ,3rd one was warm and 4th one barely held warmth so where did he say they still didn’t get hot?
     
  5. Mardanis

    Mardanis New Member

    Not sure if it helps but I did open them full bore at the lockshield end and to max (5) the opposite end as I opened each radiator, so this may be a large part of the problem. I will try balancing and see what happens!
     
  6. Severntrent

    Severntrent Screwfix Select

    Where he said 3rd was warm and 4th barely warm?
    My reply was based on the rider that each rad was tested individually but the OP has now verified that each one was opened one after each other so your balancing prognosis appears to be right.
     
    Last edited: Dec 28, 2020
    John the plumber31 likes this.
  7. John the plumber31

    John the plumber31 Active Member

    Not all the lockshields should be open to full bore ( try shutting all the lockshields off and then open the closest a quarter ,the second one half way 3rd one three quarters and the last one fully and see what happens)
     
  8. Offshore

    Offshore Active Member

    As someone who posted on here recently with a radiator problem that turned out to be a balancing issue I'm certainly no expert, but here is my tuppence worth anyway. Perhaps shut off all the rads except the one that is struggling to warm up at all - if that heats up then it definitely has a flow of hot water to it. If that's the case then it sounds like it may be getting robbed of hot water by the rest of the circuit and the system needs to be balanced. I would suggest leaving this radiator open until you get sufficient heat from it and then go round the rest of the system just cracking open each of the lock shield valves until you get heat from them too. It is very important to always have a flow path for your pump so never run the system with all the radiators shut off. I was surprised by just how little the lock shield valves had to be open to get heat from the radiators, my problem was caused by them being too far open and robbing the biggest radiator in the system of adequate flow. Hope this helps.
     
  9. John the plumber31

    John the plumber31 Active Member

    why thank you sir :)
     
    Severntrent likes this.
  10. Severntrent

    Severntrent Screwfix Select

    No prob, if I was an sparky I'd argue the toss but if you're wrong you're wrong. (Except for radiators 3 and 4 which didn't get hot )
     
    John the plumber31 likes this.
  11. John the plumber31

    John the plumber31 Active Member

    Lol , sparkies are bad :mad: besides they are all scared of water and never tidy up after themselves. You don’t Want to be one of them. ;)
     
    Severntrent likes this.
  12. Mardanis

    Mardanis New Member

    I did both. Individually to verify no blockages and then as an increasing amount of open rads.

    I have just put the system on for another try and to leave it on overnight as its about freezing point. I opened the thermostat ends upto 5 on all 8 rads. Then opened the lockshields on upstairs 4 to 1/4 open. Downstairs rads are Full bore open

    The upstair rads are now what I would consider appropriately hot without being too hot to touch.

    The downstairs rads are cold with the feed pipe lukewarm.

    I'll check it tomorrow and see what happens.
     
  13. Mardanis

    Mardanis New Member

    Okay no improvement only the upstair rads are cooler so I assume its sending the hot water out, enough to cool the upstairs but isnt heating downstairs
     
  14. Din21

    Din21 New Member

    Hi,
    I have got a similar problem with my rads, are you able to let me know what you did in the end to resolve getting heat to all if the rads. downstairs
     
  15. Notnowvicar

    Notnowvicar New Member

    Balance your system...youtube is your friend. The only issue normally is finding the first rad in a circuit. Close them all off and open in turn until one gets hot. The 1/4 turn open and on to the next one.
     
  16. Din21

    Din21 New Member

    Hi
    I know I'm late posting this, found it was the Expansion vessel which had an airlock, hence why we had the problem!
     

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