Replacing shower

[jeeves]

Hi, I am trying to get to grips with replacing my shower.

I currently have a conventional boiler that heats a cylinder of hot water on the first floor.

The shower is a thermostatic mixer - Aqualisa 'Gainsborough Ambassador'. The hot water is supplied by the cylinder (unpumped), the cold I'm not sure tbh, but overall flow is weak. The shower can have several different cartridges depending on setup and mine has a 'thermostatic shower cartridge' (other choices are multipoint or combi/hydramax/thermostatic gravity), it was in the house when we moved in, and I think dates from the 90s.

The thermostatic valve is presumably broken because, it is very difficult to get a stable temp, even a slightest creak of movement in the lever sends the temp shooting in the wrong direction. Due to a new cartridge costing over £150, I'd like to replace the whole thing with a more conventional 'bar' shower mixer valve.

1) Is there any particular type of replacement shower I should be looking for?
2) If flow is still lack lustre can I simply add a pump to boost power? in which case what sort of pump do I need for my setup.

I've included a layout picture to hopefully help. Any more info needed, please let me know.

Thank you!

 

[denso13]

Is there any particular type of replacement shower I should be looking for?

Not particularly, but make sure it is suitable for low pressure systems.

flow is still lack lustre can I simply add a pump to boost power? in which case what sort of pump do I need for my setup.

A positive head pump, but will likely need pipework alterations. The instructions should give different layout/positioning options.

 

[jeeves]

Thanks for the feedback denso, much appreciated.

So looking at the salamander videos about positive head / neagtive head pump, it confirms what you say so thanks for putting me on the right track.

Something like this then maybe?:

https://www.screwfix.com/p/stuart-turner-showermate-standard-regenerative-twin-shower-pump-1-5bar/543pg

Also when you say pipework alterations, do you mean the piping from the hot & cold of the shower feed to the pump and then piping back from the pump to the shower? or something more significant?

 

[denso13]

Also when you say pipework alterations, do you mean the piping from the hot & cold of the shower feed to the pump and then piping back from the pump to the shower? or something more significant?

If you check the instructions you'll see the preferred location is low down, usually next to the HW cylinder which will likely need some pipework alterations.

It also shows it in the loft but with strict dimensions to the bottom of the storage cistern. It isn't a case of just cutting the feeds to the shower and sticking the pump in.

From experience, loft installations are more problematic and don't work as well.