Radiator stone cold

Discussion in 'Plumbers' Talk' started by Transatlantic, Nov 5, 2016.

  1. Transatlantic

    Transatlantic New Member

    I have a large radiator in my lounge that is staying stone cold despite the heating being on and all the other radiators getting hot.

    Notes :

    - The return valve is fully on
    - The TRV is fully on
    - The pipe leading to this radiator and into the TRV is very hot at the end of the room where it comes from the attic, but gradually cools down as it gets to the TRV at which point it is less than luke warm.
    - The return pipe is stone cold
    - The radiator is stone cold
    - Bleeding the radiator lets out water, so no air.

    As it seemed like the TRV was at fault, I took off the cap and checked the pin as per some videos I have seen. The pin seems fine though. It is not stuck and springs up when pushed as expected.

    Just wondering if there is anything else I can try before calling out a plumber? :(
     
  2. Pollowick

    Pollowick Screwfix Select

    When was it last working? Is there a sludge build up in the radiator? Or a blocked valve?

    Turn off all other radiators, except one and the problem one.

    Give the problem radiator a quite few slaps with the palm of the hand along the bottom at the front - if there is a sludge build up you might shift it and having all others off (except one) puts most of the flow towards it. The one remaining on is a bypass to stop pressure building up.
     
  3. Transatlantic

    Transatlantic New Member

    When you say turn the others off, do you mean turn off both the flow valves and the return valves? or just one of the valves?
     
  4. Pollowick

    Pollowick Screwfix Select

    Both flow and return if you can - although if difficult to do, just one will do. You need to stop flow into and out of those rads.
     
  5. Transatlantic

    Transatlantic New Member

    Ok - I tried this and it got hot so didn't bother with the slaps. I assume this means my system is unbalanced?

    It also only got hot at the top, so I guess I have a lot of sludge in there.
     
  6. "It also only got hot at the top, so I guess I have a lot of sludge in there."

    That's a pretty good diagnosis.

    It's unlikely (tho' possible) that the whole rad was 'blocked' - it was probably chust a sticking rubber washer in the TRV or the lockshield. Or perhaps it had a coating of sludge which sealed it.

    But now that you are pretty certain that you do have significant sludge in your system, you should be looking to clear it out before it causes serious issues - like messing up yer boiler.

    So get a mag filter fitted (eg a Magnaclean) and chuck a couple of doses of Sentinel X800 in to your system. Hopefully this will do the trick over a few months (you'll be cleaning out the filter every week or so...)
     
  7. Pollowick

    Pollowick Screwfix Select

    Or te sludge had settled on te inlet and it needed the extra pressure to shift it.

    As DA says, get a Magnaclean in there ASAP.

    Once you have that, a few slaps to the rad will stir up the sludge and get it moving. Do that for a few days on every radiator to get the worst out then add some cleaner and run for a week or two checking the filter daily.
     
  8. KIAB

    KIAB Super Member

    MagnaClean Professional 2 among the best, can find it cheaper if you search
    you will be emptying filter two maybe three times a week for a few weeks at first, then it will be usually one once or twice a year.
    http://www.screwfix.com/p/adey-cp1-03-00022-01-2-magnetic-filtration-22mm/49961

    You can remove the radiator, take it outside & hose it through will help.

    Sentinnel X800 for a couple of weeks, a couple of flushes, refill, add Sentinnel X900 Filter Aid & X100 Inhibitor.



     
    Last edited: Nov 5, 2016
  9. Transatlantic

    Transatlantic New Member

    I've read Sentinnel X800 but haven't found anywhere that describes how to actually use it? Is it something anyone can do? or should I really be getting the plumber to do it?

    My system is an oil Wallstar combi
     
  10. First fit the Magnaclean (or other make) of filter. There is little point in loosening lots of sludge only to have it travelling around and around your system.

    Then you can add the chemicals (cleaners to begin with, until you are sure it's all good - and then a dose of inhibitor) via the filter.

    Peasy easy.
     
    KIAB likes this.
  11. Transatlantic

    Transatlantic New Member

    Well I know I wouldn't be able to fit the Magnaclean as that requires cutting pipework. But even if I did fit it, how would that help the sludge in the radiator? it seems to be designed to catch the dirt floating around the system? not the stuff stuck in one place further thown the system.
     
  12. Pollowick

    Pollowick Screwfix Select

    Why can you not cut the pipework?

    A Magnaclean will take the floating debris out first of all. Then once you add cleaner to the system the sludge in the radiator will start to go back into suspension and slapping the radiator will help to get it moving. Then, as it goes past the Magnaclean it will get caught and over a week or two most will come out.

    The other way two ways are:

    To remove each radiator in turn, take it outside and flush through with a hose - that can be a laborious and time consuming task.

    Hire a powerflush - either just the equipment or someone with a system and have run that. Not cheap and is not a quick process - also made easier if you you a cleaning fluid to start with
     
    KIAB likes this.
  13. KIAB

    KIAB Super Member

    The cleaner would dislodge a lot of the crud & this will be caught by the magnetic filter.
     
  14. KIAB

    KIAB Super Member

    A better explaination than mine.:(

    Not a fan of powerflushing, a quick way to flush your money away, better with something like X800 through system for a few weeks, put all radiator on full, should notice improvement within hours.
    Might hear a few weird noises insystem as it goes about it's work,but you need a filter to catch the crud.:)

    Was emptying filter here two or three times a week for a few weeks at first, now it's a couple of times a year.
     
  15. Transatlantic

    Transatlantic New Member

    Sorry, I mean I personally would not be able to fit it, and would need to get someone in (in relation to my previous question of adding the chemical cleaner and 'Is it something anyone can do?')
     
  16. Transatlantic

    Transatlantic New Member

    Still not sure why you need the filter though. I thought you were supposed to : (in regard to my combi system)

    - Drain system to remove existing/worst floating gunk
    - Add cleaner through radiator bleed valve or boiler filling loop
    - Refill system
    - Run system for a few weeks
    - Drain system to remove cleaner and remaining gunk
    - Refill system
    - Repeat last 2 steps a few times to make sure all cleaner is removed

    So if you're draining to remove the cleaner and newly removed gunk as recommended, why would you need the filter? ... unless you mean the filter is just to prevent future gunk build up?
     
  17. KIAB

    KIAB Super Member

    Yes.

    Usually I will turn off a radiator, drain it down just enough & remove bleed/ blanking cap & add cleaner via dosing bottle.
    Also might need to top up system abit.

    And the filter will collect future crud.
    It's a lot easy to empty filter a couple of times a week, plus any crud is in supension, so you will collect more, draining down I find you can still leave crud behind even after flushing system.
     
  18. Pollowick

    Pollowick Screwfix Select

    Totally true.


    Transatlantic - have a look at the ADEY videos and you will see how easy it is. Do you not have a friend with basic plumbing skils?
     
    KIAB likes this.
  19. Transatlantic

    Transatlantic New Member

    Nope :(

    I may give it a shot. Before I cut the pipe though, how do you drain the water that's already in there? I've looked into how to drain the water from the radiators using the drain valve, but that won't clear out the water from the pipework leading to/ inside / and way from the boiler will it? i.e the bits I'll be cutting?
     
  20. Pollowick

    Pollowick Screwfix Select

    The drain valve should take ALL water out ... someone with more knowledge of the boiler type will hopefully confirm it and give you some more direction.

    The filter should go on the final return to the boiler, after all radiators have joined back in. Before you do make any cuts, check here for confirmation that it is the right place maybe with a picture or two.
     

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