Boiler wiring query

Discussion in 'Electricians' Talk' started by BHW, Aug 25, 2018.

  1. BHW

    BHW New Member

    Evening all.
    I have a query I'm hoping someone can help me with.
    I have just had an extension built and have wet underfloor heating and radiators in rest of house .
    There is only one pump live from the boiler . Problem I have is whichever source of Heating is selected both pumps come on .
    Anyone any idea how to wire this up
    So I can have either under floor heating or radiator pump on individually ??
    I have 3 x 2 port zone valves . For underfloor , radiators and cylinder .
     
  2. peter palmer

    peter palmer Well-Known Member

    is there a manifold an wiring centre for the UFH - how many zones has it got?
     
  3. BHW

    BHW New Member

    There is a manifold but no zones as it's just one big room
     
  4. peter palmer

    peter palmer Well-Known Member

    Is it one of those single zone manifolds like this

    [​IMG]

    or a traditional multi zone one - has it got actuators on it

    If its a traditional one then I would connect the UFH pump to the brown of the UFH zone valve controlled by the UFH thermostat.
     
  5. BHW

    BHW New Member

    It has 5 ports on the manifold , the pump needs to be fired by the boiler due to pump overrun .
     
  6. peter palmer

    peter palmer Well-Known Member

    It shouldn't need to, the main pump should wire from the boiler and will overun and the UFH pump will only run when the UFH stat calls for heat.
     
  7. BHW

    BHW New Member

    There isn't a main pump . It is a heat only boiler no pump inside the boiler . Just the radiator/cylinder pump and UFH pump . Both pumps take their live from the boiler
     
  8. Lectrician

    Lectrician Screwfix Select

    The radiator/cylinder pump should also be pumping to the manifold. The UFH pump circulates the floor, not from boiler.

    Photos of plumbing?
     
    Magicspark likes this.
  9. peter palmer

    peter palmer Well-Known Member

    I agree, the pump connected to the boiler should be before the 3 zone valves or on the return near the boiler, this will pump through whichever zone valve is open. The pump for the under floor heating only circulates round the blending valve and UFH pipe circuit.

    As said pictures would be useful, I wonder if its piped up correctly even.
     
  10. Lectrician

    Lectrician Screwfix Select

    That’s my thought. Let’s see pics of the plumbing.
     
  11. BHW

    BHW New Member

    Thank you all for replies even the ones that are not helpful . All sorted no issues at all now
     
    Last edited: Sep 1, 2018
  12. Lectrician

    Lectrician Screwfix Select

    What was the Fix?
     
  13. BHW

    BHW New Member

    Time delay relay works a treat
     

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