All sorts of plumbing advice please!

Lilo22

Hi! First time poster 😊
I live in a rented cottage with a private water supply. Last week we ran out of water altogether for 3-4 days. Apparently the water table is very low after dry summer and there was also a leak which has since been repaired.
We now have water again, but pressure is too low for electric shower to work. Previously pressure was too low for “hot” setting, but worked on “warm”, (not bearable in winter). I have oil fired central heating and an immersion heater. Hot and cold water tanks are in attic. How do I know if a mixer shower would work better for me? Landlord may install this if I request, but their handyman is not a plumber to trade and I am concerned he might install something that would not work 😕 is gravity feed likely to work? Would I need pump? Would low pressure supply work with pump? Is there anything else I need to think about?
Thanks in advance!

that

Hi first time poster, welcome.

The mixers do quote a minimum working pressure. some are 0.1bar and other are 0.2bar. I would not buy the 0.2 bar one in your case. The 0.1 may be questionable too, as it will be the pressure to the top of the shower head, rather than a pipe on the ground
https://www.screwfix.com/c/bathrooms-kitchens/shower-valves/cat820336

This is why they have shower pumps to overcome the lack of pressure.

The other issue is if you pump out more water by using the shower pump than your setup can deliver.

Lilo22

Thanks! So is it the hot water or cold water that needs to be at 0.1 bar? And how big a tank would you need for that? I had a look in the attic last night but my ladder wasn’t tall enough ��

Apodemus

Do you know if your electric shower is trying to run off your incoming cold supply or the output from your cold water header tank? Changing over to a mixer run off hot and cold tanks in the attic might work, but even then, in a single storey cottage, the amount of head between the tank in the attic and the height of the shower might be quite small. While, I would be inclined to try it, it may be that such a set-up would no longer pass the legionella regulations in a tenanted property (which is probably even more of an issue on a private supply)

that

Lilo22 wrote: »

Thanks! So is it the hot water or cold water that needs to be at 0.1 bar? And how big a tank would you need for that? I had a look in the attic last night but my ladder wasn’t tall enough ��

10.33meters of water is 1 bar, so from your shower head it must be more than this and have no pipe resistance, so with a short pipe would guess you are looking about a minimum of 1.5m drop minimum, plus you have to keep the tank fuller that in can be emptied. To be honest think you need a pump.

Lilo22

I believe from the fact that the pipes go from floor level up to the back of the shower that it’s the incoming cold supply that feeds the shower? Is this better or worse?

Lilo22

The other cottages on the estate have some kind of filter/uv thing to treat the incoming water supply. Would that solve the legionella issue? My cottage doesn’t have it as the previous tenant wouldn’t allow access.

Lilo22

Thanks, it sounds like you both think there won’t be a big enough drop and a pump will be required. Would there be minimum tank size for hot and cold tanks?

that

I am unsure the speed of the flow the flow rate the make uv ineffective for legionella. For any private supply water problems, diseases and concerns, contact your council’s environmental health department. You may find out yearly water testing should be done.

Every piece of equipment-like water filters, bend in the pipe, and pipe length will have a negative effect on pressure and water rate.

Is townies often have good cold water pressure, but the hot water one is why many of us need pumps

Apodemus

Lilo22 wrote: »

The other cottages on the estate have some kind of filter/uv thing to treat the incoming water supply. Would that solve the legionella issue? My cottage doesn’t have it as the previous tenant wouldn’t allow access.

Get the estate to bring your water treatment up to the same standard as the other cottages as a priority and as a separate issue from your shower. That’s for a range of other reasons, rather than legionella.

Legionella thrives in warmer locations, can lurk in unused bits of pipe and tanks and is most dangerous when inhaled in water droplets like you might do in a shower. For these reasons, there are plumbing regulations which stop you doing some things that would otherwise seem quite straightforward - particularly in commercial situations, such as rental properties. I don’t know what your local rules might be, but your local plumber should!