How do I pick the correct shower pump?

[JoeyT]

We're redoing the bathroom. We have low pressure system (gravity fed vented), top of tank is about 1m above the shower head, 6 to 7L per minute flow rate (at the bathroom tap).

Currently we have just an electric shower (not power, no pump) cold water fed (15mm pipe from tank). Pressure isn't actually that bad, but it's a small head.

Since we're redoing the bathroom, replacing bath with a shower, girlfriend wants a dual bar mixer. Most of them say they need a high pressure system. We did stumble on this one (https://www.plumbworld.co.uk/mira-coda-pro-erd-thermostatic-bar-mixer-shower-3221-28238) that says it will work as low as 0.1bar but we do want a more powerful flow.

So I'm thinking about putting in a pump, but struggling to pick one. The pressure in the taps in the house are good enough so only need the pump for the shower, and enough positive pressure not to need a negative pressure one.

There's a lot of different pumps to choose from and many brands and big price ranges. Would I be fine with a 1.5 bar pump like this?
https://www.anchorpumps.com/niagara...-impeller-shower-pump-replaced-with-str2-1-5c
or
https://www.plumbworld.co.uk/salama...ugal-shower-bathroom-pump-rp50pt-1653-1253053
or is there a whole lot more to it?

Thanks.

 

[oldbuffer]

1. I would personally recommend a Stuart Turner Monsoon (not Showermate).
2. 1.5 bar should be sufficient, but a lot depends on the shower you go for. A 2.0 bar should be ample for anything but the most prolific rainhead.
3. Make sure that the plumbing is done properly for any shower pump. Basically needs:
3.1 Separate feed from the cold water storage cistern (CWSC).
3.2 Separate feed from the hot water cylinder (HWC). This feed must be air free, and from a special flange, or, as allowed by some manufacturers, from a downward facing tee off a sloping vent / hot water pipe.
4. The height to the shower head should be calculated from the bottom of the CWSC, not the top. It is generally a minimum of 600 mm, but is manufacturer specific, so check.
5. The pump is best situated at the base of the HWC, normally in the airing cupboard.

 

[JoeyT]

Thanks. I've studied the plumbing enough to have dreamt about it all night. Fully understand about the flange to avoid getting air in, and that it needs own feed from tank / HWC. Not sure about the pipe diameter yet, guessing it should match pump inlets of 22mm. Aware that any valves must be full width (forgot the term).

My brother will be doing the plumbing as much more confident than I am, but will still be done properly.

HWC is in airing cupboard which is the other side of the shower wall, so perfect placement. Pump will sit at the bottom next to HWC. CWSC directly above.

 

[Elkato531]

I would seriously consider a digital shower such as the Aqualisa Quartz or Visage (other brands are available) The showers are expensive but when you consider the cost of a decent shower pump, there isn't much difference.

 

[Bod ...]

I would seriously consider a digital shower such as the Aqualisa Quartz or Visage (other brands are available) The showers are expensive but when you consider the cost of a decent shower pump, there isn't much difference.

And their back up service is very good.

 

[Bod ...]

Problem with shower pumps is if you don't plumb them in to a tee in following the MIs they will not validate the warranty. Stuart Turner are buggers for this.

 

[JoeyT]

I'd need to price it all up. Budgeting around £1,000 for the entire shower but if I can convince my other half to give up the marble tiles we may be able to do it.

I heard bad things about Stuart Turner, although I suspect they're from people that didn't follow the exact requirements.

 

[JoeyT]

Girlfriend laughed in my face when I said she can control it from her phone and from her voice, so a bar mixer it is!