I have fitted a shower pump and connected it to the HW cylinder using a surrey flange. When the hot taps elsewhere in the house are turned off the pump activates for half a second. Any suggestions how to cure this please?
You might find a water hammer arrestor fitted on the feed to the taps will help.
Is this a negative or positive head pump. (i.e. has it a pressure or flow operated switch).
I suspect you've got a deadleg with air in it after the pump.
Put pump on floor of airing cupboard and fit an automatic air release valve on hot input leg. Been there done that with a pump first installed in the loft and then moved to a shelf in airing cupboard and finally fitted in the correct place as per all the shower pump installation instructions I have seen, on floor of airing cupboard next to hot tank. When installed as per instructions worked fine no bursts when bath run and no air in pump when shower run.
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