Radiator cold.

Discussion in 'OT (OFF Topic) Forums' started by SportsCoupeRich, Dec 10, 2010.

  1. SportsCoupeRich

    SportsCoupeRich Hardcore MB Enthusiast

    Messages:
    1,824
    Joined:
    Jan 17, 2005
    Location:
    Saffron Walden, Essex. Riyadh, KSA
    Car:
    RRS
    My bedroom radiator is warm at the bottom and cold at the top. I have used a bleed screw and whilst there was some air emitted, there was no water following it and nothing has changed?

    Laymans advice?
     
  2. Howard

    Howard MB Club Veteran

    Messages:
    18,624
    Joined:
    Apr 23, 2004
    Location:
    Toad Hall
    Car:
    CLS 500 / A 150
    Bleed it some more ? until the water comes out.
     
    1 person likes this.
  3. renault12ts

    renault12ts MB Club Veteran

    Messages:
    15,958
    Joined:
    Mar 5, 2009
    Car:
    2005 W215 CL500.
    Some radiators can be slow to bleed. If this is the case then turn all other rads off to force the water along and the air out.
     
    1 person likes this.
  4. OP
    OP
    SportsCoupeRich

    SportsCoupeRich Hardcore MB Enthusiast

    Messages:
    1,824
    Joined:
    Jan 17, 2005
    Location:
    Saffron Walden, Essex. Riyadh, KSA
    Car:
    RRS
    If it bleeds we can kill it?

    Thanks R12ts, will give it a go. I think it is the case that the pressure isnt high enough (is in the loft conversion). will go play....
     
  5. renault12ts

    renault12ts MB Club Veteran

    Messages:
    15,958
    Joined:
    Mar 5, 2009
    Car:
    2005 W215 CL500.
    When you have a loft conversion, it is even more important to make sure that your system is balanced. You do this by having the rads closest to the boiler practically off (at the lock shield end) and fully open farthest away from the boiler (loft). The temperature differential between water in and water out of each rad should be about 12degs C. An infra red thermometer is pretty good at helping you do this.
     
  6. Darrell

    Darrell Hardcore MB Enthusiast

    Messages:
    3,909
    Joined:
    Dec 15, 2006
    Location:
    Back in Mill Hill but sometimes in Skiathos
    Car:
    A Jaaaaag, 2016 Dacia Duster and a 2004 Carrera (996)
    Balancing a system is very important. Most people have their lockshield valves fully open.

    If you balance it properly. you will be amazed.
     
  7. x332race

    x332race Hardcore MB Enthusiast

    Messages:
    1,107
    Joined:
    Dec 10, 2005
    How high is the header tank over the radiator?

    Has rad worked ok in the past?

    May be a blockage in pipework??
     
    Last edited: Dec 10, 2010
  8. nigel cross

    nigel cross Hardcore MB Enthusiast

    Messages:
    2,414
    Joined:
    Jan 8, 2005
    Location:
    Surrey
    Car:
    W164 ML350 Audi S4
    Check your expansion tank, perhaps the ballcock is stuck, but its proberly slow fill. So bleed rad, close bleed valve wait a couple of mins and start process again.
    Allways taught that you dont bleed system with pump running, stops possibity of getting air stuck round pump
     
  9. cl55 amg

    cl55 amg Hardcore MB Enthusiast

    Messages:
    561
    Joined:
    May 28, 2009
    Location:
    Manchester
    Car:
    CL55 AMG
    How do you do this? as my nearest radiator in the cellar is always warm not hot.
    Thanks
     
  10. x332race

    x332race Hardcore MB Enthusiast

    Messages:
    1,107
    Joined:
    Dec 10, 2005
    That could be due to sludge in the system as that radiator is probably at the lowest point...you might find a good flush would do the trick.....power flush would cost about £300 - £400 or you could do what I did, get some Fenrox central heating cleaner and run this through your system for a week and then flush out thoroughly. Don't forget to refill after with a suitable corrosion inhibitor.
     
    1 person likes this.
  11. renault12ts

    renault12ts MB Club Veteran

    Messages:
    15,958
    Joined:
    Mar 5, 2009
    Car:
    2005 W215 CL500.
    See post 5.
     
  12. renault12ts

    renault12ts MB Club Veteran

    Messages:
    15,958
    Joined:
    Mar 5, 2009
    Car:
    2005 W215 CL500.
    Or remove the rad and flush it with a hose. Then open each tap (into a bucket) to make sure all is clean. Or it could be a little dirt at the lock shield end.
     
  13. nigel cross

    nigel cross Hardcore MB Enthusiast

    Messages:
    2,414
    Joined:
    Jan 8, 2005
    Location:
    Surrey
    Car:
    W164 ML350 Audi S4
    If there was sludge in the rad it would be hot at top and cold at bottom(were the sludge is)
     
  14. peter65

    peter65 Member

    Messages:
    35
    Joined:
    Feb 20, 2010
    Location:
    Barnard Castle
    Car:
    CLK320 Cabriolet
    If its a pressured sealed system the vessel sounds like it needs more pressure, buy opening the inlet valve and raising to around 1.5bar
     
  15. cl55 amg

    cl55 amg Hardcore MB Enthusiast

    Messages:
    561
    Joined:
    May 28, 2009
    Location:
    Manchester
    Car:
    CL55 AMG
Tags:

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.