Boiler diverter valve

Discussion in 'UK DIY' started by Ian Nutt, Nov 8, 2003.

  1. Ian Nutt

    Ian Nutt Guest

    I have a Vaillant combi boiler and seem to have a problem with the
    diverter valve. The hot water only comes on when the heating is on. I
    have taken the diverter valve out of the boiler to study it and can
    see that the diaphram is supposed to push up a pin that forces a
    hammer to fall and make a contact that ignites the burner and diverts
    water into the hot tap system.

    When I turn the hot water tap on you can see the hammer try to move
    down to make the switch contact, but it does not have the energy. It
    would seem that there is not enough pressure to push it hard enough.

    Does anyone out there understand what i'm talking about, or, even
    better, know what the problem might be?

    Kind regards.
     
    Ian Nutt, Nov 8, 2003
    #1
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  2. Ian Nutt

    Ed Sirett Guest

    On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:

    > I have a Vaillant combi boiler and seem to have a problem with the
    > diverter valve. The hot water only comes on when the heating is on. I
    > have taken the diverter valve out of the boiler to study it and can
    > see that the diaphram is supposed to push up a pin that forces a
    > hammer to fall and make a contact that ignites the burner and diverts
    > water into the hot tap system.
    >
    > When I turn the hot water tap on you can see the hammer try to move
    > down to make the switch contact, but it does not have the energy. It
    > would seem that there is not enough pressure to push it hard enough.
    >
    > Does anyone out there understand what i'm talking about, or, even
    > better, know what the problem might be?
    >

    Which model? They work by very different mechanisms.


    --
    Ed Sirett - Property maintainer and registered gas fitter.
    The FAQ for uk.diy is at www.diyfaq.org.uk
    Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
    Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
     
    Ed Sirett, Nov 8, 2003
    #2
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  3. Ian Nutt

    Ian Nutt Guest

    "Ed Sirett" <> wrote in message news:<>...
    > On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    >
    > > I have a Vaillant combi boiler and seem to have a problem with the
    > > diverter valve. The hot water only comes on when the heating is on. I
    > > have taken the diverter valve out of the boiler to study it and can
    > > see that the diaphram is supposed to push up a pin that forces a
    > > hammer to fall and make a contact that ignites the burner and diverts
    > > water into the hot tap system.
    > >
    > > When I turn the hot water tap on you can see the hammer try to move
    > > down to make the switch contact, but it does not have the energy. It
    > > would seem that there is not enough pressure to push it hard enough.
    > >
    > > Does anyone out there understand what i'm talking about, or, even
    > > better, know what the problem might be?
    > >

    > Which model? They work by very different mechanisms.


    Ed - thanks for getting back. I don't know! Cannot see a model number
    written anywhere and have no documents on it. Do you know how I can
    identify it?

    Cheers.
     
    Ian Nutt, Nov 9, 2003
    #3
  4. Ian Nutt

    Ed Sirett Guest

    On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:

    > "Ed Sirett" <> wrote in message news:<>...
    >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    >>
    >> > I have a Vaillant combi boiler and seem to have a problem with the
    >> > diverter valve. The hot water only comes on when the heating is on. I
    >> > have taken the diverter valve out of the boiler to study it and can
    >> > see that the diaphram is supposed to push up a pin that forces a
    >> > hammer to fall and make a contact that ignites the burner and diverts
    >> > water into the hot tap system.
    >> >
    >> > When I turn the hot water tap on you can see the hammer try to move
    >> > down to make the switch contact, but it does not have the energy. It
    >> > would seem that there is not enough pressure to push it hard enough.
    >> >
    >> > Does anyone out there understand what i'm talking about, or, even
    >> > better, know what the problem might be?
    >> >

    >> Which model? They work by very different mechanisms.

    >
    > Ed - thanks for getting back. I don't know! Cannot see a model number
    > written anywhere and have no documents on it. Do you know how I can
    > identify it?
    >

    Please describe the general appearance - eg. grey/black/beige control
    panel. Permanent pilot or electronic ignition? Fan assisted flue or
    balanced natural draught flue?

    Anyway from the description is it most likely a split diaphragm in the
    water flow sensor.

    If you look around and perhaps remove or swing-down a panel you will
    likely find the model type and rating plate.


    --
    Ed Sirett - Property maintainer and registered gas fitter.
    The FAQ for uk.diy is at www.diyfaq.org.uk
    Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
    Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
     
    Ed Sirett, Nov 9, 2003
    #4
  5. Ian Nutt

    Ian Nutt Guest

    "Ed Sirett" <> wrote in message news:<>...
    > On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:
    >
    > > "Ed Sirett" <> wrote in message news:<>...
    > >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    > >>
    > >> > I have a Vaillant combi boiler and seem to have a problem with the
    > >> > diverter valve. The hot water only comes on when the heating is on. I
    > >> > have taken the diverter valve out of the boiler to study it and can
    > >> > see that the diaphram is supposed to push up a pin that forces a
    > >> > hammer to fall and make a contact that ignites the burner and diverts
    > >> > water into the hot tap system.
    > >> >
    > >> > When I turn the hot water tap on you can see the hammer try to move
    > >> > down to make the switch contact, but it does not have the energy. It
    > >> > would seem that there is not enough pressure to push it hard enough.
    > >> >
    > >> > Does anyone out there understand what i'm talking about, or, even
    > >> > better, know what the problem might be?
    > >> >
    > >> Which model? They work by very different mechanisms.

    > >
    > > Ed - thanks for getting back. I don't know! Cannot see a model number
    > > written anywhere and have no documents on it. Do you know how I can
    > > identify it?
    > >

    > Please describe the general appearance - eg. grey/black/beige control
    > panel. Permanent pilot or electronic ignition? Fan assisted flue or
    > balanced natural draught flue?
    >
    > Anyway from the description is it most likely a split diaphragm in the
    > water flow sensor.
    >
    > If you look around and perhaps remove or swing-down a panel you will
    > likely find the model type and rating plate.



    Ed,

    I have taken the right hand side panel off and there is no
    identification plate visible anywhere, just various stickers with
    nothing that looks like a serial number. The pump has 'Type VP5'
    written on it, but I assume this refers to the pump.

    The control panel is black, with green dials and a pressure gauge
    bottom right. There are 4 dials (on/off/relight, water temp, ch temp,
    function setting) and 7 indicator lights that light up green to
    indicate when the burner is on etc. It is electronic ignition and
    naturally vented flued I think.

    I took the brass diverter valve out over the weekend and took it
    apart. There was a water chamber above and below the rubber diaphragm,
    and the diaphragm didn't look out of shape. There is a pin attached to
    a plate which is supposed to push up when the pressure of the mains
    water is released. I made sure it was loose enough, and refitted it.
    It didnt do any good - when the hot water tap is turned on you can see
    the hammer try to fall to make the electrnic circuit that will ignite
    the boiler, but it is obvious that the pin inside is not moving up far
    enough to push this little white plaster hammer down to make the
    circuit.

    Does this sound familiar?
     
    Ian Nutt, Nov 10, 2003
    #5
  6. Ian Nutt

    Ed Sirett Guest

    On Mon, 10 Nov 2003 10:46:15 +0000, Ian Nutt wrote:

    > "Ed Sirett" <> wrote in message news:<>...
    >> On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:
    >>
    >> > "Ed Sirett" <> wrote in message news:<>...
    >> >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    >> >>
    >> >> > I have a Vaillant combi boiler and seem to have a problem with the
    >> >> > diverter valve. The hot water only comes on when the heating is on. I
    >> >> > have taken the diverter valve out of the boiler to study it and can
    >> >> > see that the diaphram is supposed to push up a pin that forces a
    >> >> > hammer to fall and make a contact that ignites the burner and diverts
    >> >> > water into the hot tap system.
    >> >> >
    >> >> > When I turn the hot water tap on you can see the hammer try to move
    >> >> > down to make the switch contact, but it does not have the energy. It
    >> >> > would seem that there is not enough pressure to push it hard enough.
    >> >> >
    >> >> > Does anyone out there understand what i'm talking about, or, even
    >> >> > better, know what the problem might be?
    >> >> >
    >> >> Which model? They work by very different mechanisms.
    >> >
    >> > Ed - thanks for getting back. I don't know! Cannot see a model number
    >> > written anywhere and have no documents on it. Do you know how I can
    >> > identify it?
    >> >

    >> Please describe the general appearance - eg. grey/black/beige control
    >> panel. Permanent pilot or electronic ignition? Fan assisted flue or
    >> balanced natural draught flue?
    >>
    >> Anyway from the description is it most likely a split diaphragm in the
    >> water flow sensor.
    >>
    >> If you look around and perhaps remove or swing-down a panel you will
    >> likely find the model type and rating plate.

    >
    >
    > Ed,
    >
    > I have taken the right hand side panel off and there is no
    > identification plate visible anywhere, just various stickers with
    > nothing that looks like a serial number. The pump has 'Type VP5'
    > written on it, but I assume this refers to the pump.
    >
    > The control panel is black, with green dials and a pressure gauge
    > bottom right. There are 4 dials (on/off/relight, water temp, ch temp,
    > function setting) and 7 indicator lights that light up green to
    > indicate when the burner is on etc. It is electronic ignition and
    > naturally vented flued I think.
    >

    Aha we have a vaillant VUW this is the model comes between the VCW and the
    latest Turbomax+ series. It is forced flue with a fan. IIRC.

    In this model the DHW is fired from the microswitch mounted on the
    right hand side of the diverter valve/flow valve.
    The water flow diaphragm operates directly on the diverter valve and the
    microswitch.

    You could have a problem if the diverter valve is stuck/sticky.

    --
    Ed Sirett - Property maintainer and registered gas fitter.
    The FAQ for uk.diy is at www.diyfaq.org.uk
    Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
    Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
     
    Ed Sirett, Nov 10, 2003
    #6
  7. Ian Nutt

    Ian Nutt Guest

    "Ed Sirett" <> wrote in message news:<>...
    > On Mon, 10 Nov 2003 10:46:15 +0000, Ian Nutt wrote:
    >
    > > "Ed Sirett" <> wrote in message news:<>...
    > >> On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:
    > >>
    > >> > "Ed Sirett" <> wrote in message news:<>...
    > >> >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    > >> >>
    > >> >> > I have a Vaillant combi boiler and seem to have a problem with the
    > >> >> > diverter valve. The hot water only comes on when the heating is on. I
    > >> >> > have taken the diverter valve out of the boiler to study it and can
    > >> >> > see that the diaphram is supposed to push up a pin that forces a
    > >> >> > hammer to fall and make a contact that ignites the burner and diverts
    > >> >> > water into the hot tap system.
    > >> >> >
    > >> >> > When I turn the hot water tap on you can see the hammer try to move
    > >> >> > down to make the switch contact, but it does not have the energy. It
    > >> >> > would seem that there is not enough pressure to push it hard enough.
    > >> >> >
    > >> >> > Does anyone out there understand what i'm talking about, or, even
    > >> >> > better, know what the problem might be?
    > >> >> >
    > >> >> Which model? They work by very different mechanisms.
    > >> >
    > >> > Ed - thanks for getting back. I don't know! Cannot see a model number
    > >> > written anywhere and have no documents on it. Do you know how I can
    > >> > identify it?
    > >> >
    > >> Please describe the general appearance - eg. grey/black/beige control
    > >> panel. Permanent pilot or electronic ignition? Fan assisted flue or
    > >> balanced natural draught flue?
    > >>
    > >> Anyway from the description is it most likely a split diaphragm in the
    > >> water flow sensor.
    > >>
    > >> If you look around and perhaps remove or swing-down a panel you will
    > >> likely find the model type and rating plate.

    > >
    > >
    > > Ed,
    > >
    > > I have taken the right hand side panel off and there is no
    > > identification plate visible anywhere, just various stickers with
    > > nothing that looks like a serial number. The pump has 'Type VP5'
    > > written on it, but I assume this refers to the pump.
    > >
    > > The control panel is black, with green dials and a pressure gauge
    > > bottom right. There are 4 dials (on/off/relight, water temp, ch temp,
    > > function setting) and 7 indicator lights that light up green to
    > > indicate when the burner is on etc. It is electronic ignition and
    > > naturally vented flued I think.
    > >

    > Aha we have a vaillant VUW this is the model comes between the VCW and the
    > latest Turbomax+ series. It is forced flue with a fan. IIRC.
    >
    > In this model the DHW is fired from the microswitch mounted on the
    > right hand side of the diverter valve/flow valve.
    > The water flow diaphragm operates directly on the diverter valve and the
    > microswitch.
    >
    > You could have a problem if the diverter valve is stuck/sticky.


    Exactly right! The microswitch is a tiny fellow which makes the
    circuit when this white plastic hammer I keep mentioning pushes down
    on it.

    How do I ensure the diverter valve isn't sticky? Any tips?

    Thanks again for your continuing attention.
     
    Ian Nutt, Nov 11, 2003
    #7
  8. Ian Nutt

    Ed Sirett Guest

    On Tue, 11 Nov 2003 03:37:10 +0000, Ian Nutt wrote:

    > "Ed Sirett" <> wrote in message news:<>...
    >> On Mon, 10 Nov 2003 10:46:15 +0000, Ian Nutt wrote:
    >>
    >> > "Ed Sirett" <> wrote in message news:<>...
    >> >> On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:
    >> >>
    >> >> > "Ed Sirett" <> wrote in message news:<>...
    >> >> >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    >> >> >>
    >> >> >> > I have a Vaillant combi boiler and seem to have a problem with the
    >> >> >> > diverter valve. The hot water only comes on when the heating is on. I
    >> >> >> > have taken the diverter valve out of the boiler to study it and can
    >> >> >> > see that the diaphram is supposed to push up a pin that forces a
    >> >> >> > hammer to fall and make a contact that ignites the burner and diverts
    >> >> >> > water into the hot tap system.
    >> >> >> >
    >> >> >> > When I turn the hot water tap on you can see the hammer try to move
    >> >> >> > down to make the switch contact, but it does not have the energy. It
    >> >> >> > would seem that there is not enough pressure to push it hard enough.
    >> >> >> >
    >> >> >> > Does anyone out there understand what i'm talking about, or, even
    >> >> >> > better, know what the problem might be?
    >> >> >> >
    >> >> >> Which model? They work by very different mechanisms.
    >> >> >
    >> >> > Ed - thanks for getting back. I don't know! Cannot see a model number
    >> >> > written anywhere and have no documents on it. Do you know how I can
    >> >> > identify it?
    >> >> >
    >> >> Please describe the general appearance - eg. grey/black/beige control
    >> >> panel. Permanent pilot or electronic ignition? Fan assisted flue or
    >> >> balanced natural draught flue?
    >> >>
    >> >> Anyway from the description is it most likely a split diaphragm in the
    >> >> water flow sensor.
    >> >>
    >> >> If you look around and perhaps remove or swing-down a panel you will
    >> >> likely find the model type and rating plate.
    >> >
    >> >
    >> > Ed,
    >> >
    >> > I have taken the right hand side panel off and there is no
    >> > identification plate visible anywhere, just various stickers with
    >> > nothing that looks like a serial number. The pump has 'Type VP5'
    >> > written on it, but I assume this refers to the pump.
    >> >
    >> > The control panel is black, with green dials and a pressure gauge
    >> > bottom right. There are 4 dials (on/off/relight, water temp, ch temp,
    >> > function setting) and 7 indicator lights that light up green to
    >> > indicate when the burner is on etc. It is electronic ignition and
    >> > naturally vented flued I think.
    >> >

    >> Aha we have a vaillant VUW this is the model comes between the VCW and the
    >> latest Turbomax+ series. It is forced flue with a fan. IIRC.
    >>
    >> In this model the DHW is fired from the microswitch mounted on the
    >> right hand side of the diverter valve/flow valve.
    >> The water flow diaphragm operates directly on the diverter valve and the
    >> microswitch.
    >>
    >> You could have a problem if the diverter valve is stuck/sticky.

    >
    > Exactly right! The microswitch is a tiny fellow which makes the
    > circuit when this white plastic hammer I keep mentioning pushes down
    > on it.
    >
    > How do I ensure the diverter valve isn't sticky? Any tips?
    >
    > Thanks again for your continuing attention.


    There may be an inadequate flow of water to correctly operate the valve.
    There may be a split diaphragm in the valve.
    The diverter valve might be too stiff to move easily enough:
    i) failed lubrication
    ii) sludge etc. in pirmary
    iii) mechanical failure (unlikely)

    The micro switch could be iffy - not enough to show when you operate it
    with a finger but enough when operated by the valves.

    --
    Ed Sirett - Property maintainer and registered gas fitter.
    The FAQ for uk.diy is at www.diyfaq.org.uk
    Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
    Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
     
    Ed Sirett, Nov 12, 2003
    #8
  9. Ian Nutt

    Ian Nutt Guest

    "Ed Sirett" <> wrote in message news:<>...
    > On Tue, 11 Nov 2003 03:37:10 +0000, Ian Nutt wrote:
    >
    > > "Ed Sirett" <> wrote in message news:<>...
    > >> On Mon, 10 Nov 2003 10:46:15 +0000, Ian Nutt wrote:
    > >>
    > >> > "Ed Sirett" <> wrote in message news:<>...
    > >> >> On Sun, 09 Nov 2003 05:22:31 +0000, Ian Nutt wrote:
    > >> >>
    > >> >> > "Ed Sirett" <> wrote in message news:<>...
    > >> >> >> On Sat, 08 Nov 2003 09:50:44 +0000, Ian Nutt wrote:
    > >> >> >>
    > >> >> >> > I have a Vaillant combi boiler and seem to have a problem with the
    > >> >> >> > diverter valve. The hot water only comes on when the heating is on. I
    > >> >> >> > have taken the diverter valve out of the boiler to study it and can
    > >> >> >> > see that the diaphram is supposed to push up a pin that forces a
    > >> >> >> > hammer to fall and make a contact that ignites the burner and diverts
    > >> >> >> > water into the hot tap system.
    > >> >> >> >
    > >> >> >> > When I turn the hot water tap on you can see the hammer try to move
    > >> >> >> > down to make the switch contact, but it does not have the energy. It
    > >> >> >> > would seem that there is not enough pressure to push it hard enough.
    > >> >> >> >
    > >> >> >> > Does anyone out there understand what i'm talking about, or, even
    > >> >> >> > better, know what the problem might be?
    > >> >> >> >
    > >> >> >> Which model? They work by very different mechanisms.
    > >> >> >
    > >> >> > Ed - thanks for getting back. I don't know! Cannot see a model number
    > >> >> > written anywhere and have no documents on it. Do you know how I can
    > >> >> > identify it?
    > >> >> >
    > >> >> Please describe the general appearance - eg. grey/black/beige control
    > >> >> panel. Permanent pilot or electronic ignition? Fan assisted flue or
    > >> >> balanced natural draught flue?
    > >> >>
    > >> >> Anyway from the description is it most likely a split diaphragm in the
    > >> >> water flow sensor.
    > >> >>
    > >> >> If you look around and perhaps remove or swing-down a panel you will
    > >> >> likely find the model type and rating plate.
    > >> >
    > >> >
    > >> > Ed,
    > >> >
    > >> > I have taken the right hand side panel off and there is no
    > >> > identification plate visible anywhere, just various stickers with
    > >> > nothing that looks like a serial number. The pump has 'Type VP5'
    > >> > written on it, but I assume this refers to the pump.
    > >> >
    > >> > The control panel is black, with green dials and a pressure gauge
    > >> > bottom right. There are 4 dials (on/off/relight, water temp, ch temp,
    > >> > function setting) and 7 indicator lights that light up green to
    > >> > indicate when the burner is on etc. It is electronic ignition and
    > >> > naturally vented flued I think.
    > >> >
    > >> Aha we have a vaillant VUW this is the model comes between the VCW and the
    > >> latest Turbomax+ series. It is forced flue with a fan. IIRC.
    > >>
    > >> In this model the DHW is fired from the microswitch mounted on the
    > >> right hand side of the diverter valve/flow valve.
    > >> The water flow diaphragm operates directly on the diverter valve and the
    > >> microswitch.
    > >>
    > >> You could have a problem if the diverter valve is stuck/sticky.

    > >
    > > Exactly right! The microswitch is a tiny fellow which makes the
    > > circuit when this white plastic hammer I keep mentioning pushes down
    > > on it.
    > >
    > > How do I ensure the diverter valve isn't sticky? Any tips?
    > >
    > > Thanks again for your continuing attention.

    >
    > There may be an inadequate flow of water to correctly operate the valve.
    > There may be a split diaphragm in the valve.
    > The diverter valve might be too stiff to move easily enough:
    > i) failed lubrication
    > ii) sludge etc. in pirmary
    > iii) mechanical failure (unlikely)
    >
    > The micro switch could be iffy - not enough to show when you operate it
    > with a finger but enough when operated by the valves.


    I have bought a new diaphragm and will fit that on Saturday - ill let you know!
     
    Ian Nutt, Nov 13, 2003
    #9
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