1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Explain my CH and HW system to me

Discussion in 'Plumbing and Central Heating' started by coursemyhorse, 16 Sep 2020.

  1. coursemyhorse

    coursemyhorse

    Joined:
    7 Oct 2012
    Messages:
    35
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi, just moved into a new house (EDIT: 5 bedrooms if this helps understand system type) and we have some plumbing issues and questions. I think I need to try to understand my setup a bit to know what I can/can't attempt myself and to try to troubleshoot things. I don't know a lot about these things and do aim to get someone in to help, but I thought it would be good to try to understand it a bit myself as well for the future since this is my first house I owned.

    The house has a loft conversion where behind a void on this top floor, the boiler is installed. I seem to recall it is not a combi boiler but it's modern and only a few years old. I believe this system is possibly referred to as a pressurised system?

    There is no water tank. In the airing cupboard on the middle floor, there is a large modern cylinder model Joule Cyclone CY250L with an 18L Aquasystem ARB18 Expansion Vessel. Inside the airing cupboard there is a Drayton standard timer/programmer single channel which only does the HW. Next to this there is a British Gas wireless receiver model WR1. At the bottom of the cylinder is a thermostat for the water temperature set to I think 60 degrees celsius. There is also an immersion lead left lose out the bottom presumably since this was never hooked up due to cost of running it.

    In the hallway there is a British Gas smart linked thermostat. Also in the Hallway is a switch which controls some underfloor heating in the downstairs toilet. When I press the switch, it powers on an additional timer/programmer in the hall (model unknown until I take it off the wall and read the back) which I believe only controls/affects the downstairs toilet underfloor heating. I believe this to be an electric underfloor heating install, but not sure how to tell.

    In the kitchen there is an underfloor heating installation of the wet type. In one of the kitchen cupboards there are a load of pipes like a manifold system and a pump and other things. Also in the kitchen there is an additional programmer/timer model PR-1 single channel. When I take it off the wall, there are actual powered wires going to it. 4 of them. 1 being an earth.

    All other rooms have normal radiators without TRVs.

    One shower is an Aqualisa with posh electronic control start and temp switches. Not sure if an additional pump is involved here its all behind tiling. Other shower on top floor is more of a simple on/off tap and a single tap to control the mix/temp. Neither are electric as when I have no HW we get no hot showers.

    When I spoke to the original owner of the house and I asked about the heating, he didn't really have a clue (was all done before he owned the house and he had only been there a couple of years). He claimed to never really use the programmer in the kitchen, and just used the one in the hall.


    Problems/queries

    1: When the HW is on but CH is off, the kitchen underfloor heating wet system still comes on. I'm not sure it is supposed to. We don't want it to. Is there a fault or could this be by design? I have tried turning the hall temperature right down to about 15 degrees C, and the kitchen timer I have set to OFF. Still the underfloor heating comes on.

    2: Also with the HW on and CH off, we noticed two of the back bedroom radiators still sometimes get ever so slightly warm. On one day, they got noticeably warm. No other rads do this, just the mid level back rooms.

    3: We have two towel rails. One for mid level bathroom and one for topfloor bathroom. The top floor one seems to come on fine with CH. Mid level one doesn't seem to. Are towel rails always linked to the CH loop only? These are wet ones with water pipes going in and out at the bottom. I tried bleeding the mid level one and water came straight out with no air.

    4: I believe this system to be a pressurised type which is different to any house I have been in before. Sorry if this is wrong terminology to use. Does this mean that if I attempt to repair a tap that is dodgey by isolating the water supply, will I cause issues with the balance/pressure? Would it need to be re-pressurised and if so how? There is a gauge in the airing cupboard which reads 1.5 bar. Does this also mean if I cock something up it's much more dangerous as water will come out at high pressure?


    Thanks for any help with this.
     
    Last edited: 16 Sep 2020
  2. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,136
    Thanks Received:
    1,346
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    Unfortunately it's impossible to say over a forum, you will need to have someone physically inspect everything, which may include lifting floors. There could be many reasons for the various symptoms you describe, defective components, bad pipework design, air locks, botched additions, reverse circulation, faulty or bad wiring.....etc.,

    Regarding the hot water cylinder from your description it would appear to be an 'unvented hot water system'. You can find info on the various types of hot water system by clicking here. If it is unvented, you have to be trained and hold a G3 Ticket to work on it. It's not DIY.
     
  3. Sponsored Links
  4. coursemyhorse

    coursemyhorse

    Joined:
    7 Oct 2012
    Messages:
    35
    Thanks Received:
    0
    Country:
    United Kingdom
    Can you define "work" on "it". I can't do what to what specifically? Say I want to change a tap cartridge or head...is that "working on it" ? Thanks for your help.
     
  5. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,136
    Thanks Received:
    1,346
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    As I understand it changing a sink tap is OK, but DIY work on the cylinder and any components relating to it (eg expansion vessel, pressure relief, controller etc.,) are not. I haven't had the Building Regs training so a comment from someone who has a G3 ticket would be more definitive. There should be a notice on the cylinder to the user stating that they shouldn't work on it, and it should also have an annual service.

    If you want to read the the full details, Part G of the building regulations is available on line.

    The danger comes from the pressure that builds up in a sealed system due to the expansion of water when heated. There are some erm...interesting videos of cylinders blowing up when the safety devices are removed. There's an example here. Don't let it frighten you though, properly installed and serviced cylinders are quite safe.
     
  6. Sponsored Links
Loading...

Share This Page