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Wonder if anybody can help me diagnose a fault on a power shower fed from a pump. Pump is coming on but shower is running cold.
Basically, the arrangement is this:-
Thermostatic mixer shower on ground floor of bungalow.
Fed from a grundfos watermill twin impeller pump in the loft.
Cold water storage cistern (roughly 230 litres) in attic, 1.8 metres from base of cwsc to attic floor joists. Hot water cylinder in attic, sat on base on the floor joists so decent little bit of head. Shower pump on attic floor a couple of metres away from cylinder.
Got to property, turned shower on, pump kicked in and stayed on but shower ran cold. Tried mixer valve on all settings to no avail. Went up in attic, felt hot pipe from cylinder to pump, was quite hot to inlet side of pump, but barely warm outlet side.
I isolated and disconnected the pump and opened both iso valves on the inlet side, both had good flow of water. I then re-connected pump with outlet side open ended, and opened the valves to see the water flow through the pump (with the electricity off so it wouldnt pump) and found the cold side was fine, but the hot side was getting very poor flow. So it was fine TO the pump but POOR after going through it.
I then rang grundfos, guy told me it may be a broken impeller, and to turn the pump around, i.e. the hot pipe connected to what was previously the cold side of the pump. He said to then turn the shower on and if i got belting hot water, it was probably the impeller that had gone.
I did this, but when i turned the shower on, the pump didnt even kick in. so that was that test buggered. and the same side of the pump as before still was not passing much water through at all. even though there was plenty on the inlet side.
I havent even got round to testing the mixer cartridge yet, i just thought start with the first thing in the sequence, the pump, just thought it was strange that one side would pass lots of water with the electricity off and the other wouldnt. Anyone experienced anything similar to this? Pump is a Grundfos Watermill twin impeller pump, pretty sure its positive head but that should be fine shower head is alot lower than cwsc.
many thanks
Basically, the arrangement is this:-
Thermostatic mixer shower on ground floor of bungalow.
Fed from a grundfos watermill twin impeller pump in the loft.
Cold water storage cistern (roughly 230 litres) in attic, 1.8 metres from base of cwsc to attic floor joists. Hot water cylinder in attic, sat on base on the floor joists so decent little bit of head. Shower pump on attic floor a couple of metres away from cylinder.
Got to property, turned shower on, pump kicked in and stayed on but shower ran cold. Tried mixer valve on all settings to no avail. Went up in attic, felt hot pipe from cylinder to pump, was quite hot to inlet side of pump, but barely warm outlet side.
I isolated and disconnected the pump and opened both iso valves on the inlet side, both had good flow of water. I then re-connected pump with outlet side open ended, and opened the valves to see the water flow through the pump (with the electricity off so it wouldnt pump) and found the cold side was fine, but the hot side was getting very poor flow. So it was fine TO the pump but POOR after going through it.
I then rang grundfos, guy told me it may be a broken impeller, and to turn the pump around, i.e. the hot pipe connected to what was previously the cold side of the pump. He said to then turn the shower on and if i got belting hot water, it was probably the impeller that had gone.
I did this, but when i turned the shower on, the pump didnt even kick in. so that was that test buggered. and the same side of the pump as before still was not passing much water through at all. even though there was plenty on the inlet side.
I havent even got round to testing the mixer cartridge yet, i just thought start with the first thing in the sequence, the pump, just thought it was strange that one side would pass lots of water with the electricity off and the other wouldnt. Anyone experienced anything similar to this? Pump is a Grundfos Watermill twin impeller pump, pretty sure its positive head but that should be fine shower head is alot lower than cwsc.
many thanks
