Electric shower fed from water tank

Folks
I've recently moved house and inherited a bit of a mess of dodgy DIY stuff (and it's bad when I, the master of dodgy DIY, consider it dodgy).
Having just plumbed and fitted an upstairs bathroom, with many thanks for some good advice from the group, I've discovered the shower in the downstairs bathroom is fed from the water tank.
I've always understood that an electric shower had to be fed from the mains supply. The question is, is this just an annoyance to be sorted when time permits or is it a danger which should be sorted as soon as possible?
The flow rate is poor, understandably, but just about acceptable which is probably due to the shower being on the ground floor and the tank being in the attic above the first floor i.e. about a floor and a half above.
Second question - should an electric shower be plumbed with 15mm or 22mm pipe?
thanks
tommy
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message

In my previous house, there was a pumped electric shower already there when we moved in which was connected to the mains. The pressure was good but it meant that if anyone so much as looked at the cold tap in the kitchen or the washing mashine or the garden tap or even mentioned teh word tap, the pressure went berserk, when the shower was on. You could stand in teh kitchen and turn the cold tap on for a moment and 5 seconds later get a scream from the shower room as the occupier got scalded and frozen in quick succession.
We then got a new shower put in with a new pump and it was done directly from the attic storage tank by a local plumber who usually knew exactly what he was doing. He recommended that route. I know this is a DIY group but plumbing in showers is a bit scary (I DID do the tiling) for me. Anyway. the pressure was about the same because, I think the limiting factor is how fast you can heat the water, not how much water you can push through.
In my current house, the shower is from the attic tank also. These 3 showers were all pumped electric (i.e. pump plus heating).
Des

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message

Some showers are designed to run from the mains water supply, some to run from a water tank.
The instructions, which you might not have, will show you what type you have.
I ran a 3/4" pipe from the attic to the ground floor where the new shower is located with the last meter in 1/2".
Francis
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not so. They have minimum and maximum pressures. Whether it is from the mains or tank is irrelevant.

is
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

run
If you look at the showers' installation manuals it will show that your statement is not true.
Francis
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.