vokera riello loosing pressure, how to figure out why?

Discussion in 'Plumbers' Talk' started by forthetime, Sep 3, 2019.

  1. forthetime

    forthetime New Member

    Well my boiler was loosing about 1 cm of pressure per day all last winter but my heating has been off ie the heating ie rads dont come on unless it gets below a certain temperature in the house and rads not been on since April and the boiler has stayed at exactly the same spot 1bar , until now (Sept) the heating has been back on for the last week and the boiler pressure has dropped to 0.5 bars!!
    An engineer has checked the boiler over and can not find any fault with the boiler and no leaks from the boiler.

    What could this indicate where the fault lyes?
     
  2. just pumps

    just pumps Well-Known Member

    Did this happen to start around March this year?
     
  3. terrymac

    terrymac Well-Known Member

    When central heating is on for a few hours ,what does the pressure rise to ?
    What do you mean by " losing 1cm per day " ? Do you mean 1 bar ?
     
  4. forthetime

    forthetime New Member

    The boiler started to loose pressure last year around oct, then continued until the heating went off in April this year and it stayed at 1 bar since April this year and now heating is back on the boiler is loosing pressure again.
    Although whats strange is the Chrome Towel Radiator in the bathroom is turned off but just checked it and it had alot of water around the valve on one side. But how can that be if rad is turned off?

    by 1cm per day I mean not 1 bar as its too much but if you look at the bar clock and you measure around 1 cm thats about how much, not 1 bar or I could say 1/10th of a bar a day.

    Pressure doesnt normally rise when heating is on normally, sometimes rises a tiny tiny bit but not much.
     
  5. just pumps

    just pumps Well-Known Member

    And is the pipe under the sink still leaking
     
  6. forthetime

    forthetime New Member

    The pipe under the sink I can not tell for sure if its still leaking, but dont think its a CH pipe as its cold. Plus pressure in boiler been fine anyhow for months.
     
  7. terrymac

    terrymac Well-Known Member

    Eh ????
     
  8. terrymac

    terrymac Well-Known Member

    Sounds like you have a leak on the valve of the towel radiator , probably through the spindle.
    Not familiar with your boiler ,I assume its a combi ,and you don't have a hot water cylinder connected to it.
    Have you checked the pressure relief pipework outside isn't dripping water ?
     
  9. forthetime

    forthetime New Member

    If theres a leak on the valve of the towel radiator, even though the the towel radiator is turned off, can this still cause the pressure to drop on the boiler?
    Yep a combi. Cant see the pressure relief pipework outside as its Im in a flat, so very high up.
    don't have a hot water cylinder connected to it - I am not sure, know theres a water tank in the loft. (yes its a flat but still has a loft)
     
  10. terrymac

    terrymac Well-Known Member

    Towel rad has two valves. Are they both closed off ? If water is escaping from the valve ,its coming out of the sealed system ,and will result in pressure loss.
    If you can't see the PRV pipework ,then this can't be ruled out as a possible point of further water loss.
     
  11. forthetime

    forthetime New Member

    I am not sure if both valves are closed off? I know I turned both of them and the rad no longer got hot.

    https://imgur.com/O7SqG2D

    Heres a pic of it and Ive put an arrow where when I put my hand there was water on it. Is there anything I can do with this bathroom rad to see if the boiler will stop losing pressure?
     
  12. forthetime

    forthetime New Member

    Ive been looking for a video on how to turn off a Bathroom Rad but all the vids are of regular rads and are different. Is bleeding a rad the same as isolating a rad?
     
  13. terrymac

    terrymac Well-Known Member

    Bleeding air from the rad is totally different. Turning one valve off would stop the rad from heating up. To turn both fully off would then prevent water flowing through the rad and effectively isolate it from the pressurised sealed water system. It would still be full of water obviously. If one or other of the valves are not working properly ,and not fully closing ( bit like when you turn a tap off on the kitchen sink ,but it still drips water continually ,as its valve is not fully closing ),then the rad is still part of the sealed system. There are many types of rad valves,most close off by turning fully clockwise ,some have to have a cap removed first. Yours appears to have a silver disc that unscrews ,then the chrome handle pulls off to reveal the shaft.
    There is a simple way to find out if both valves are closed fully. Close both ,then open the bleed screw at the top, water should come out
    Immediately for a very short time ,then stop completely. (Before doing any of this ,the rad should be bled of air before the valves are closed ,and boiler pressure topped up to 1 bar if need be).
     
  14. forthetime

    forthetime New Member

    Had another independant tradesman out to look at boiler and the bathroom rad where I thought it was leaking. He said doesnt seem to be leaky probs just water from the shower splashing on it. He had a look at outside and said it looked dry. I said maybe its the expansion but he dismissed that. I said well its going down to zero every 2 -3 weeks that cant be right, he didnt seem concerned.
    I have since checked the tops of the rads which I didnt know you had to also do. The living room rad and the bedroom rad had water on and around the nut part, not sure whats thats called but heres a pic of it. Could this be a leak? Could this be causing the boiler to lose pressure? How can I stop it leaking? ie turning it or tightening it? if so how? which parts? which direction? thanks all in advance.

    https://imgur.com/gctVm5R

    https://imgur.com/hQjSSSu
     
  15. terrymac

    terrymac Well-Known Member

    Your pic shows an air bleed valve. The small square in the middle is turned with a key to bleed air out of the radiator.The whole valve screws into the radiator by means of tightening the large nut. It is sealed into the radiator with a rubber O ring. There is often ,on the opposite end of the radiator ,another nut without the air bleed facility. That is just a cap nut, which can also leak. It is fitted the same as the other and with an O ring seal.
    If the seal fails ,water can escape from the system.
    To rectify ,they have to be removed and new O rings fitted ( PTFE tape is also used to seal the threads).
    Before removing ,the two radiator valves at the bottom of the rad must be fully closed.
     
  16. just pumps

    just pumps Well-Known Member

    Wouldn`t be concerned if "Independant tradesman" wasn`t.
     
  17. forthetime

    forthetime New Member

    Thanks, how do I remove the air bleed valve?
     
  18. terrymac

    terrymac Well-Known Member

    C
    Close both rad valves.
    Use the little square to bleed out air/ water and excess pressure.
    Then put a spanner on the hexagonal nut and turning anti clockwise ,unscrew it out.
    Have towel ready as a small amount of water will come out as its unscrewed.
    Refit in reverse ,with a new O ring and PTFE tape wrapped around the thread.
     
    Baxi Boy likes this.
  19. forthetime

    forthetime New Member

    Thanks so much, could this be why the boiler is loosing pressure?

    Is there a video on Youtube showing how to do this? What would I specifcally search for in the search button?

    I have bought some tools to fix this, I bought:

    Diall White PTFE tape (L)12m (W)12mm
    Sentinel Leak sealer, 50ml
    Magnusson 8" Adjustable Wrench
    Magnusson S2 steel PZ0 Pozidriv Screwdriver (L)75mm
    Magnusson S2 steel PZ0 Pozidriv Screwdriver (L)75mm
    Magnusson S2 steel PZ2 Pozidriv Screwdriver (L)125mm
    Rothenberger 10" Water pump pliers

    Is that everything I need to do this? If anything else is needed toolwise, can you tell me what thanks again

    "Before removing ,the two radiator valves at the bottom of the rad must be fully closed." Which direction closes them? Obviously the temeperature valve is obvious as I turn it too "off" as opposed to 1-5
     
  20. forthetime

    forthetime New Member

    Its also leaking from the other nut without the air bleed facility.

    Is there anyway to isolate those two rads so no water can leak from it anymore until it is repaired? Will simply turning it to Off rather than 1-5 stop the water leaking from the rads as the carpets getting very wet.
     

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