Problems with Bristan Shower - Please help

[loziv]

Sorry about the long post but I hope some experienced plumbers will be able to help me out with identifying the problem please
Thanks
Lauren

Our Bristan shower (which is over the bath) combined with a varispeed 50 water pump has started to play up.

What happens is when we run a bath (for example bathing the kids) then about 5-10 mins later when we try to use the shower to wash their hair the shower does not seem to draw any cold (which makes the shower dangerously hot) or sometimes hot water into the flow, which is causing the pump to make a loud noise as it tries to pull the water through?

Could it be air in the system, as sometimes when running the cold bath tap to get rid of the problem with the shower the water splutters out before going full flow? However yesterday when running the hot bath tap there was hardly any water coming out?

After turning the shower on and off, running the bath taps etc seems to get rid of the problem, but I would like to know the cause and the recommended fix please

I have checked the cold water tank in the loft which is 114 litres and it is filling up fine when water is being drawn through the shower so I am at a loss to work out why this happens sometimes and other occassions its fine

Not sure if this is relevant bu my boiler is a Worcester Bosch Greenstar 30CDi system boiler http://www.worcester-bosch.co.uk/homeowner/products/gas-boilers/greenstar-30cdi-system http://www.worcester-bosch.co.uk/homeowner/products/what-is-a-system-boiler with just a cold water tank in the loft

 

[seco services]

Is the bath taps linked to the pump aswell or just the shower ?

 

[loziv]

Hi

I don't think so

When I run the bath taps the pump doesnt come on, only when the shower is on

 

[seco services]

Then your bath taps shouldn't alter the problem with your shower.

For the shower i would try checking the pump filters first, They are located in the flexi pipes on the pump end, the side connections.

You say you ran the bath hot tap and hardly any water flowed ?

 

[loziv]

Hi

If it was a problem with the filters then it would happen everytime the shower is turned on, but this only happens after the bath has been filled and then you try and use the shower.

That's right after the bath run, say about 5 mins later I tried the shower to wash the childrens hair then the pump was making noises as it couldnt draw water through properly.

So I tried the hot tap of the bath and the water was hardly coming out and the same from the hot tap of the sink in the bathroom?

Could there be a problem with the pipework from the cold water tank (which is 115 litres) to the hot water tank, which is causing the hot tank to not fill properly after a large amount of water has been drawn? Perhaps silt in the pipework?

 

[PetePlumb]

Sounds like your cold water cistern could be running out of water. If you can get up in the loft, take off the lid of your cistern and have a look at the water level when it does this.

 

[loziv]

Ok thanks will do if this is the case what's the solution ?

Many thanks

 

[PetePlumb]

Ideally, a bigger cistern.

But you could install a second ball valve, to fill the cistern quicker.

Second option is the cheaper option.