Worcester Greenstar 24i Junior

Discussion in 'Plumbers' Talk' started by Pilkinb, Sep 3, 2014.

  1. Pilkinb

    Pilkinb New Member

    Need some advice and guidance.
    I have just moved into a 2 bed bungalow today which has a Greenstar 24i Junior Combi boiler installed. Tried to use the hot water today and found that the hot water remained cold and the boiler did not start. I then noticed a mechanical timer and a 3 port valve so I went into the loft and found a hot water tank and cold water tank.

    I switched the timer to constant hot water and eventually the water in the hot tank heated up. I also noticed that someone had written "Open Vented System" on the drop down front panel.

    I have double checked the model number and all other labels and it is definitely a combi boiler.

    Is this a normal practice to install a combi but just use the Heating side of the boiler as a normal heating boiler. I am definitely confused and would appreciate any guidance you can give
     
  2. G&W Plumbing & Heating

    G&W Plumbing & Heating Active Member

    When you say 2 tanks in roof, is one a cylinder?, is it unvented hot water? Do you have one big & one small tank, do you have a cylinder on ground level?
     
  3. Pilkinb

    Pilkinb New Member

    Sorry for the late reply, been a little busy unpacking stuff.

    Went into the loft to check exactly what was installed...

    Firstly there is a large cold water tank built on a platform about 6 foot above the loft floor.
    Secondly there is a Hot Water cylinder at floor level fed from the large cold water tank. This is an open vented system with the usual vent pipe into the top of the cold water tank. There is a second open vent pipe also feeding into the top of the cold water tank which I assume is from the heating. There are no tanks or cylinders installed at ground level.

    Just to confuse things even more, there is a small cold water tank hidden behind the large tank but this is not connected - the pipes are there but have been physically unscrewed so there is no water in this small tank at all.

    So just to review the situation...... the installed combi boiler is connected to an open vented heating and hot water system and the hot water side of the combi boiler is not in use. Also the pressure gauge on the combi boiler reads "0" bar.
    combi.jpg
     

    Attached Files:

  4. Dave does Gas

    Dave does Gas Screwfix Select

    You sure its not a System boiler. How many pipes coming out of the bottom?
    Highly unusual for it not to be sealed system
    It you can post a picture of the silver plate on the right, hopefully its got a GC number on it thats how to identify the boiler

    If its 41-311-68 then its a 24i system boiler not a combi

    Edit:-

    Having said that Ive just looked at the manufacturers instructions and its not designed to be an open vent system. looks to me like someone has done a bodge job.

    Get someone in to have a look. These boilers are designed to run on a pressurised system only by not running it on pressure can only cause it damage.
     
    Last edited: Sep 7, 2014
  5. Jitender

    Jitender Screwfix Select

    We had a Worcester 28i Greenstar Junior in the last house, its a combination boiler. The fitters left the old tanks in the loft, so is there a possibility that these are not connected?
     
  6. Pilkinb

    Pilkinb New Member

    Further update:-

    First the boiler is in fact a 28i Junior not a 24i junior as I previously stated.

    The info on the Panel says
    Greenstar 28i Junior
    ID: 77161 30142
    GC Nr. G20 47 311 87

    The Pipework is:-

    2 x 22mm Flow & Return
    1 x 15mm Cold water in
    1 x 15mm Gas
    1 x 15mm Pressure relief
    1 x 22mm Condensate drain
    The 15mm cold out has been capped off.

    Also one of the 22mm pipes goes to a 3 port Valve.

    So I think this confirms that this is a Combi Boiler plumbed as a system boiler
     
  7. G&W Plumbing & Heating

    G&W Plumbing & Heating Active Member

    You can have a system or combi working on a gravity fed hot water cylinder, it's a bit daft for the combi but it works, you can have then one bathroom being mains fed
     
  8. Dave does Gas

    Dave does Gas Screwfix Select

    The big problem you have is that these boilers are not designed as open vented boilers, they need to be pressurised to work correctly.
    You can check this in the manufacture instructions on page 10. If you don't have a copy you can get the PDF from the worcester site.
    Also the gas should be in 22mm, You may have and under gassed appliance.
    If you have just moved in Im surprised that your solicitor didn't bother to check for the gas works notification certificates from the install.
    You defiantly need someone in to check it over as it looks like it been a DIY bodge job in the past and may be in not the safest condition.
    Sorry for the bad news, Im not trying to put the frighteners on but there are too many things that have been done wrong with that boiler to say it was professionally installed. You can call gas safe and ask for a free inspection, they will have one of their inspectors look at it and give you the all clear or not but only on the gas safety side, most will advise you about any faults in the system.
    Please keep us informed of any developments.
     
  9. Glad its Friday

    Glad its Friday Active Member

    Always difficult to advise without actually being there. But it sounds like the tank in the loft is the header for the domestic hot water supply. The indirect water side from the combi is in fact pressurised fine (sounds like the pressure is a bit low and needs topping up?). If this is the case, then the set up is ok and you've no worries Mr Pilk.

    As G&W says, you've then got a pressurised hot water outlet from the combi for your shower or something.
    If the pipe run for the gas is quite short then 15mm for the gas could be ok. If it is under-gassed, the boiler will behave more like a 24kw model. But worth checking especially if you've other gas appliances on the go in the house.

    So, sounds like it is a pressurised system, you may want to get someone in to check it out for you although I'm not convinced it is a DIY bodge at all. A local established experienced GSR business def better than calling out Gas Safe. Ask the local guy to service it for you and ask his advice about the system and the gas pipe size.
     
  10. plumberboy

    plumberboy Well-Known Member

    Sounds like a bodge to me regardless of whether its a diy bodge or a trade bodge.:(
     
  11. Dave does Gas

    Dave does Gas Screwfix Select


    Defiantly not GIF the MI's clearly say that the gas run cannot be smaller at any point than the inlet connection. Worcesters are all 22mm. If the OP has 15mm he has an issue with the installation and should get it checked.
     
  12. Glad its Friday

    Glad its Friday Active Member

    ok, I'm not a Worcester fan, assumed that they had a 15mm input on the Junior. Many manufacturers do. So worth getting that checked out, however, he may still have enough gas at the boiler.
     
  13. Dave does Gas

    Dave does Gas Screwfix Select

    Thats a shame I am after a Worcester fan for an older 24 SBi I got called to today :)
     
  14. Glad its Friday

    Glad its Friday Active Member

    Ah, not able to help you with that, despite all my hot air (never heard of the 24 SBi). Cannot fault Worcester customer service, but they are pricey, lots of plastic inside and their warranties are not very long compared to others unless you can become a 'gold' installer and fit 50 boilers a month! (slight exaggeration)
     
  15. Dave does Gas

    Dave does Gas Screwfix Select

    Your right about their installers programme which is why I'm signed up with Vaillant and Glowworm as an approved installer. Better boilers as well, particularly for installer after sales care. Both are far superior for replacing parts and diagnostics. As for the 24 SBi its an older system boiler. Much the same as the old style CDi's
     
  16. Glad its Friday

    Glad its Friday Active Member

    Thanks for that, we also fit the Glow-worms and Vaillants, putting in a 837 combi now, real bit of quality inside in my view. Offer the 10 years warranty on the Glow-worms, not had a single call back other than servicing so far. Ideal Logic+ is our other preferred boiler.
     

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