Switching to power showers from electric shower

What size is the cylinder?

The definition of a Power shower in that it puts out at least 10LPM. Because of this there is no such thing as a low pressure power shower.

There are better options than the Mira Event XS Dual. This has old style noisy motor. It also comes with cheap plastic hoses. Mira parts are expensive making this shower expensive to repair. Mira themselves have so little confidence in this shower that they only offer a 12 month warranty. All other power showers on sale in Ireland have at least 24 months. Some have 5 years.

The Triton Novel SR is a silent running power shower. Far better quality than the Mira. It comes with Chrome hose & 24 months warranty. It has 3 parts inside it so very little can go wrong with it. A Mira Event XS replacement thermostatic cartridge is €250 pluss shipping. Thermostatic cartridge for the novel is €65 plus shipping

Triton also do a dual head that works very well with the Novel SR

Triton Novel SR & the dual kit are only around €460 for both. Mira Event XS Dual is close to €700

There isn't any issue splitting 3/4 inch hot feed to feed two showers (run the 3/4 inch as close to the shower as possible. There isn't a problem running both power showers at the some time even. Tank size is the big issue here.

It's worth getting away from the belief that the hot water is free. You could sell the energy back to the grid rather than use it for water. This put's a value on the hot water. Last time I looked you could get 15 cent selling electricity. This means the "free" hot water costs 15 cent per unit. You could still be far cheaper using the electric shower. It uses far less water. A 10 minute shower electric shower is still cheaper than a 10 minute power shower using "free" hot water. I prefer the power shower myself. Just pointing out what so many miss, it's not "free" hot water

why not just put a pump in the hot press?

It’s a tidier job and you’ll have much nicer looking showers.

The best power shower is a bar mixer with dual head (rain head) & and dedicated 3 bar monsoon pump imo.

This is what I would recommend for a bathroom remodel or if re-tiling the shower.

Sure, it gives you lots of options in terms of aesthetics in the context of a new bathroom fit out.

But you are into bigger expense, and in most cases there isn’t an appreciable increase in performance vs what is achieved with Triton Novel SR for example, which delivers 14L per minute.

3Bar is the max pressure cut off on the pump, it doesn’t tell you about the flow rate - but yes ultimately the sky is the limit with a suitable pump and mixer bar. Many of the mira units have max flows of 24L/min at 5 bar feed. At 3 bar that will be about 16-18 L/min.

Where are you getting 7 minutes from? It should be approx 10-11. The cylinder is really too small for any comfort.

That’s 98 litres at 60 degrees.

When you mix with cold to bring it down to 40 degrees, it’s about 11 minutes typically.

That’s with the shower on full tilt.