Shower only works when sink tap is running!!

[SophAP]

I have just had a new salamander pump fitted to by hot water boiler and ever since the shower will only run if I leave the hot tap running on the sink. The plumber who fitted it has been back 5 times and is at a loss as to what is as he says it's worked while he's been here. Any suggestions would be great fully received as I have no idea about these things. Thanks Sophie

 

[IWalkLikeHimaMartian]

There are positive pressure pumps and there are negative pressure pumps.
Positive pressure pumps need something like a minimum of 300mm head of water so that when the tap/shower is turned on, some water runs, however little, and that small amount of running water causes the pump to work.
Negative pressure pumps work on the loss of pressure to cause the pump to activate.
There are also single and multiple outlet pumps. Obviously single: for one shower, and multiple for several outlets.

If your shower does not have the minimum amount of head of water, and you have a positive pressure pump, the water will not run though the shower sufficiently to activate the pump.
If you have an air lock in the pipework, you will have similar symptoms. Dirty filter on the pump can also create problems.

 

[oilboffin]

You will need to fit a switch on a pull cord to start the shower easy thing for a sparky to do.Bob

 

[nortonj]

Hold the shower head as low as possible when you turn your shower on, if it works then you dont have enough head of pressure to activate your shower.

 

[Agile]

I despair of these "plumbers" who cannot work out simple problems.

Hardly rocket science.

I think your "hot water boiler" is actually a hot water cylinder!

Tony

 

[HERTS P&D]

You need one of these:

http://www.screwfix.com/p/stuart-turner-monsoon-u-positive-negative-head-shower-pump-2-0bar/95061

Andy

 

[Madrab]

To be honest and not taking away from your plumber, he/she should have ensured that the hot water feed had enough min throughput (flow) to activate the flow switches on the pump, before it went in. It's really is part of the pre-check when putting in a pumped shower. Where is the bottom of cold cistern in relation to the head of the shower? I take it the other checks have been done? Dedicated feed from a flanged tapping on the HW cylinder? System bled? No high spots in supply pipework?

If you just want it fixed and don't mind the extra step to a shower then put the pump power on a switch as @oilboffin mentions. If you don't then it's a universal pump that needs to go in.