Posting a message to the forum will remove the above advertisement

Discuss Central heating system loosing pressure in the Central Heating Forum area at UKPlumbersForums.co.uk.

  1. chris301up

    chris301up New Member

    Can anyone please advise

    I have a central heating system comprising of 7 radiators and a Saunier Duval Thema F23 combination boiler

    During the spring and summer period the pressure remains constant at around 1 - 1.5 bar and I don't usually have to re-pressurise it

    However, during the autumn and winter period, the pressure drops fairly rapidly and I usually have to re-pressurise every 1 - 2 days or so.

    I rarely use the central heating , unless it's absolutely necessary, as I simply cannot afford it, so tend rely solely on the gas fire. This doesn't prevent the pressure dropping though even when it's not in use during the periods in question.

    I have checked for any leaks as best as I can but am at a bit of a loss why this only occurs


    Any advice would be greatly appreciated
     
  2. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    Have you checked the pipe that pokes out the wall outside? Is this dripping when the heating is on. Also does the pressure rise when the heating is on?
     
  3. chris301up

    chris301up New Member

    I know the pressure relief outlet doesn't leak but I haven't checked the pressure rises when heating is on. Will do that and post result. Thanks
     
  4. chris301up

    chris301up New Member

    Right. I've just run the CH for about half an hour or so and can tell you that the pipe protruding through the wall is not dripping, but trickling out in a steady stream. The pressure has also risen to just about 2 bar. I suspect a serious problem??
     
  5. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Not a serious problem but it needs addressing rather than waiting
     
    • Agree Agree x 1
  6. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    As above mate get it checked
     
  7. chris301up

    chris301up New Member

    Further to my earlier posts I've just noticed that the water trickling out of the pipe protruding through the wall is hot. Didn't notice this before!!

    I have been awaiting the possibility of boiler replacement under the government scheme, but apparently I'm not eligible for it?
    Will have to see about having this boiler sorted in the interim.
     
  8. Stigster

    Stigster Plumber

    It could be as simple as having the expansion vessel recharged and possibly a new Temperature & Pressure relief valve if it won't seat properly. Not something you can do yourself but not major works either.
     
  9. chris301up

    chris301up New Member

    I have just had a guy round to have a look at the ongoing issue but he can't seem to locate the expansion vessel recharge valve anywhere.

    The only one he can find is located on top of the pump unit, which is the same as a tyre valve, but there is insufficient room to get a air pump to attach to this as there simply is insufficient room

    Does anyone know where this may be located or is this the only one within the system?
     

    Attached Files:

  10. chris301up

    chris301up New Member

    Right. Just an update.

    I decided to take the left hand side panel off the boiler and have managed to locate the expansion vessel. For anyone else who owns a Saunier Duval F23E Thema, it's red and situated immediately behind the burner unit behind the boiler itself. The main pipe is clearly visible entering the centre of the expansion vessel from the front and you can 'feel' the valve on the top left hand side. Around 11 o'clock,

    I have drained the central heating system and then topped the air back up to 1 bar but, when turning on the central heating, the water still comes out of the pipe on outside wall.

    I will say it doesn't appear to be running quite so much, but it is still more than a trickle.

    Would anyone say that it may be worth replacing the pressure relief valve?
     
  11. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Gas safe engy
     
    • Like Like x 1
  12. chris301up

    chris301up New Member

    What does that mean. "Gas Safe Engineer"?

    My son-in-law's Dad is registered as 'gas safe' and, if I can get hold of him was going to ask him to check it out.
     
  13. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Best option as you can't really take the cover off unless you are qualified
     
    • Agree Agree x 1
  14. chris301up

    chris301up New Member

    The cover doesn't have to come off for the PRV. It's underneath
     
  15. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    No but you've already removed the cover to get to the expansion vessel ;)
     
    • Like Like x 1
  16. chris301up

    chris301up New Member

    Fair enough. But I asked many, many times how to find the expansion vessel and no-came back with an answer. Even the guy I had round the other day had no idea where it was? I felt I had no option but just to take a look. Not difficult.

    I would never attempt to mess with the gas though.
     
  17. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Could of told you where the vessel was but fault finding on a gas boiler you need to be gas safe
     
    • Agree Agree x 1
  18. Simon F

    Simon F Trusted Plumber GSR

    I would recommend not getting this 'guy' back again, ???
    is your fire more efficient than your boiler??
     
  19. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    I would never attempt to mess with the gas though.[/QUOTE]
    By taking the case off... YOU HAVE!!!
     
  20. chris301up

    chris301up New Member

    Why are all you 'gas' people so secretive and operate in such a 'close knit' society? I haven't messed with the 'gas' itself and would NEVER do so. The casing as been removed on several occasions previously for plastering and decorating etc.. Whats the problem here?

    If it's such a major issue then why didn't someone have the decency to tell me when I first asked for advice, particularly when trying to locate the expansion vessel?

    To be registered as 'gas safe' do you have to abide by equivalent rules similar to the 'hippocratic oath' or enter into a secret 'fraternity' as members of the 'magic circle' do?
     
    • Funny Funny x 1
  21. Last Plumber

    Last Plumber Plumber GSR Top Contributor!!

    https://www.gassaferegister.co.uk/media/1449/who-can-legally-work-on-a-gas-appliance-factsheet.pdf


    No secrets!
     
    • Like Like x 1
    • Agree Agree x 1
  22. chris301up

    chris301up New Member

    Thank you

    I've just read through it, particularly the section shown below, and it doesn't actually clarify if I can take the covers off or not. I don't have to unscrew anything as the panels just 'pop' into place. So are they decorative or an integral part of the appliance? I suppose this is a matter of 'interpretation'?

    I'm not going to do anything with it now anyway. Just don't know whether it's worth having a new PRV fitted or, if I can find a way of getting some funds together, replacing it as a matter of course. They are just so expensive!


    Can I take the case off my gas appliance?
    It depends on whether the case is purely decorative or whether it is an integral part of the appliance.

    Decorative casing: These cases can usually be removed by the consumer e.g. can be lifted off or are hinged panels and do not need to be unscrewed. A decorative case can be removed safely by the consumer or anybody else remembering to follow any manufacturer’s instructions and warning labels and making sure you have safely isolated any electrical parts. However, if you are in any doubt, always use a Gas Safe registered engineer.
     
  23. gmartine

    gmartine GSR

    Integral casing:
    Many appliances have cases, which in addition to being decorative, function as a part of the combustion circuit and form an important seal around the gas carrying components e.g. burner, combustion chamber, gas valve etc. If removing the case involves undoing a number of screws, this normally means it is a functional case and it should not be removed by the consumer or a person who is not Gas Safe registered.

    The warnings against unqualified casing removal are for your own saftey as you do not have the means to test whether the combustion circuit has been affected.
     
    Last edited: Nov 4, 2017
  24. Last Plumber

    Last Plumber Plumber GSR Top Contributor!!

    We are not the ‘Gas Police’ and you may be a very competent individual. However, you must understand that it would be foolish for any of us to offer instruction on repairing Gas Appliances to people not deemed competent? Especially on an open public Forum.

    It is not a secretive society, more a careful, safety focused one.
     
    • Winner Winner x 1
  25. chris301up

    chris301up New Member


    As I stated in the post there aren't any screws to be undone. The front just pulls down and the casing just slots on to flat tabs. I cannot say anymore and fully understand what you're saying otherwise.
     
    • Like Like x 1
  26. chris301up

    chris301up New Member


    As I stated in the post there aren't any screws to be undone. The front just pulls down and the casing just slots on to flat tabs. I cannot say anymore and fully understand what you're saying otherwise.
     
  27. Gasinspect

    Gasinspect Member

    Doesn't sound like an experienced repair engineer. That is air vent on pump, nothing to do with expansion. Did he try reseting the prv by turning the top? It is spring loaded and sometimes debris stops it shutting. But for a minimum charge would be worth replacing it anyway.
     
    Last edited by a moderator: Nov 4, 2017
  28. gmartine

    gmartine GSR

    Then your screws or fasteners are probably missing.
     
Loading...
Similar Threads - Central heating system Forum Date
Glow-worm central heating system not heating up properly Central Heating Forum Dec 1, 2017
Air in central heating system ( lots of it!) Central Heating Forum Nov 25, 2017