Air in sealed heating system

Discussion in 'Plumbers' Talk' started by Chilla, May 5, 2016.

  1. Crowsfoot

    Crowsfoot Screwfix Select

    Chilla, because your system is sealed and has no contact with the outside AP I don't think any of this will matter.
    Look for something more simple is my advice.
  2. Chilla

    Chilla New Member

    Hi, thanks for the tip, what I am not sure I know how to round the gland and flange seals. (well tbh, I *know* I don't know this :)) Could you explain further..
  3. chippie244

    chippie244 Super Member

    Ryluer isn't a plumber, he is however an imbecile o_Oo_O
    Ryluer likes this.
  4. Ryluer

    Ryluer Well-Known Member

    The gland seals are inside the isolating valve. The valve flange connects to the pump with a seal between. Rubber ones being the best.

    Have you diyed the plumbing yourself?
  5. Ryluer

    Ryluer Well-Known Member

    If your pump inlet isolator looks like the image below then that is what I am referring too.
  6. Chilla, is your boiler a combi? Or do you have a separate hot cylinder?

    If the latter, where is that cylinder located?

    Can you explain further your "some poorly angled piping, so this radiator comes off a high point..." comment in your first post? Any chance of a photo?
  7. Chilla

    Chilla New Member

    Cool, I will have a look for the isolator this weekend.
  8. Chilla

    Chilla New Member

    Yup, its a old combi (though not condensing)

    [/QUOTE]Can you explain further your "some poorly angled piping, so this radiator comes off a high point..." comment in your first post? Any chance of a photo?[/QUOTE]

    So attached is a very poor sketch of the radiator. The pipes rise up from the ground floor, and the radiator is on the 1st floor. The radiator comes off a section of pipe that is right at the top of the joists (almost touching the floorboards), this 22mm pipe then drops back down after 1 m and continues along in the middle of the joists. I think this is why this radiator collects all the air. Thinking about why this is done, I think it is so the plumber could make a 90deg bend in the 22mm copper by bending the pipe rather than using an elbow. Fitting this in made the junction awkward. IMG_20160513_085705655_HDR.jpg

    I think I might drain the radiator and shift the pipes on this radiator, so at least I am not woken up in the morning by a gurgling rad...

    Attached Files:

  9. So it's the rad on the first floor wot fills with air - but there are two further storeys above?

    There's nothing hugely weird about that plumbing - it should be quite possible to shift any air along them when filling the system. I guess it's possible that with so many other rads on different floors, each taking some of the pump's flow, there chust isn't enough circulating force to move that air bubble fully along. So it blows a bubble into that rad every now and then.

    I suspect it's just air that's sitting in the high points of your pipework and works its way along and into a rad over time.

    If you try shut off all other rads (just use the 'temp adjust' valve - not the 'lockshield') and then run the boiler through this one airy valve, see if you can shift all that trapped air into it - and bleed it orf once and for all.

    Is the pump built in to the boiler, or separate?

    (Does that rad actually heat up properly?)

    (Is the amount of air you need to bleed becoming less and less over time - or does it seem to 'refill' the same amount each time?)
  10. Chilla

    Chilla New Member

    That is good to know. Yes, if I turn off all the other rads I can push the air through, (but it comes back). Also the rads all heat up nicely. The amount of air changes, but it does not seem to be getting much less (apart from the ~week or so after the refill).
  11. If the air keeps coming back, I'm at a complete loss, Chilla... :(
  12. Davetoff

    Davetoff New Member

    Hi Chilla,

    Did you manage to resolve this problem? If so could you let me know as I have a very similar situation, thanks.

  13. Stretchy007

    Stretchy007 New Member

    Hi Peeps.
    New to this Forum.
    Came across it as I was doing a Bit of Research.
    Had a similar problem with a small amount of Air Entering my Heating System.
    After trying various Fixes over the last few Years such as System Cleaning, Internal Leak Sealers, replacing various washers I could find through out the System etc.
    Anyhoot to the Point.
    The Air always settled at 2 high points in the System.
    Bathroom Towel Warmer and the Combi Boiler.
    Combi is the Highest, manual Bleed Vent on Both.
    Bleeding the air out twice a week became a Household Chore.
    Slight Noise coming from Combi Pump lets Me know it due for a vent.
    Not such a big deal, just a bit of clambering to get to the Combi Manual Vent as it is in My Bedroom (Upstairs).
    Always tested the Expelling Air with a Ciggy Lighter to Check for Hydrogen (Corrosion) Non.
    Sat down one day and started Scratching my Bonce.
    Thinking back to my History of the System.
    2012 New Combi. 2013 New Rad in the Lounge.
    Points to the Rad???
    Not quite. The Rad Vent and Plug.
    Tempory Fix achieved with Lashings of Silicone Sealant applied to any Plug/Vent showing discolouration with the Rads Warm and Heating Off.
    In for a Penny in for a Pound. Replaced all Rad Vents and Plugs.
    You know the Type 1/2" BSP with a little Rubber O Ring.
    Problem Fixed. Yippee.
    But why would a Leak on the Top of the Rad as in Vent and Plug in my Lounge affect the High Points and NOT the Rad itself?
    Hence the Research.
  14. Stretchy007

    Stretchy007 New Member

    Quick Question.
    Any change
    Quick Question.
    Any change in the System pressure?
    As for my little problem there was no change whatsoever, even though being Vented a Little Twice a Week.

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