Salamander pump won't kick in without lowering shower head

28 Apr 2008
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United Kingdom
Please can somebody help me?! We've recently fitted a new bathroom and have installed a Salamander RSP50 pump (in the airing cupboard) connected to a Grohe Grohtherm 3000 Bar mixer shower with a Grohe Movario 5 shower head onto our gravity fed water system.

When we turn on the mixer the water trickles out and on many occasions the pump will not kick in (sometimes it will after a few seconds) However, if we lower the shower head - it then kicks in.

Once working and the showerhead is replaced in the holder, the shower is fine for a short while but then pressure slowly reduces and on some occasions the pump totally stops. Its really frustrating as we were all excited in finally having the bathroom finished! We'd appreciate any advice on what might be the cause and what we can do to solve it.

simple diagram of set up
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sounds like you haven't got enough gravity head to kick the pump in.
as for stopping half way through a shower maybe drawing in air and reducing flow there cutting pump out.
cheers for the speedy reply I guess the bathroom is about 2m away from the airing cupboard. All pipe work is 15mm. I reckon there is maybe 2ft of head between the cold water tank in the loft and the showerhead - could I still need a negative head pump for that? Is it possible air in the pump/pipework could be causing it ?
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no you don't need a neg pump for this.
how long does the shower work for before shutting itself down ?
can you hear any air in pipework around pump when running ?
probably no longer than ten mins - but it doesn't always shut itself down - most of the time it gradually loses pressure to an annoying level - although we've only used it a few time since commisioning on Saturday. Don't think I can hear any air around pump (although what would this sound like exactly?)
have you checked your cws tank in loft is of 50 galls or more and your not running it dry as that sounds about the right length of time for this to happen.

as for not kicking in remove your shower head and isolate pump and check your getting 1 litre/min per side hot or cold flow from the shower valve or the pump won't kick in.
I'm pretty sure the tank is ok (its been recently installed as new and was spec'd into the project (although I will check this) - I'll give the 1ltr/min check a go tonight when I get home. What should I do if its not up to that rate?
raise the cws tank or 22mm pipework.
have you fitted any isolation valves in the pipework as certain ones can restrict the flow.
how far do you have to drop the showerhead so it kicks in ?
yes apart from the built in isolation valves on the pump there are isolation valves on the hot and cold feeds (the type with the wheel you turn rather than the ball-o-fix) type. Would all the pipework have to be 22mm or just to the pump (the pump has 15mm connectors though)- otherwise all sorts of disruption now the bathrooms been finished/tiled etc! have to drop the shower head a couple of feet I guess
i'd try raise the tank first.
need to check the other problem of it reducing flow during shower maybe help alot as it may be drawing air in.
where could it be drawing in air from? and how would i fix this?! Sorry for all the questions!!
something tells me the tanks not suppying enough stored water.
to small.
as remember it is supplying to feeds hot cylinder/cold
fair enough - I'll investigate this. But if once its stopped you then lower the shower head it - fires up again - so I'm thinking maybe there is enough water there?

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