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Discuss New pump electrics problem in the Central Heating Forum area at UKPlumbersForums.co.uk.

  1. Jpsmith

    Jpsmith New Member


    I have just fitted a new pump Grundfos alpha1, but it just starts for about 3 seconds and then goes dead as if it has no power.
    I plugged the pump directly into the mains and it works fine so I can’t figure out what is wrong.
    It is a y plan system with a nest heatlink and thermostat.

    Any help would be greatly appreciated as I am pulling my hair out.

  2. John.g

    John.g Active Member

    Is the "power 0n" still indicating (lit) even when it appears to be dead.? assuming you have the grundfos alpha1 vs the alpha1 L which requires a app to configure but (whichever model) if it is working OK on the mains then it might point to the output from the nest/thermostat(s), check for voltage from this supply.
  3. Millsy 82

    Millsy 82 Plumber GSR Top Contributor!!

    Is it just on the heating by any chance? Have you got power to orange and grey with hot water off of your 3 way valve?
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