Combi, Unvented,or Conventional system.... Please help

I have just moved to an area where there is a lot of market gardeners and i believe that during the summer they put a high demand on the water system which in turn will have an effect on my domestic water supply.

I currently have a conventional system with an airing cupboard and a header tank in the attic which is old and is due to be replaced.

There is only one bathroom with a really poor electric shower that you have to run around in to get wet.

I would like to have a combi boiler so that I can have instant hot water and maybe a decent shower...

But due to the very irregular water pressure am I wanting to much??

Have I got to replace like for like or is there another option?

Any advise will be much appreciated

Stick with what you have as you can put a new tank in and then put a decent shower and pump in. A combo does have instant HW but if you don't have good pressure the shower will be a bit hit and miss.

^+1

if you have poor water pressure then you need to stick with a conventional system with a tank,

then as Badfish says you can have a pumped shower to increase the pressure.

Only a small point; if you are in a soft water area and

there is a high demand for water in the growing season

there is every liklihood that the water will be harder in

the growing season because it will come from a variety

of sources. It may be a good thing to install some kind

of filtration system to the proposed shower.

Thanks for the info...

Will just update the system I have add a pump as advised.

Thanks again

Just my two pence worth:

Combi boilers are rubbish, unless you get a really large one. Okay for a shower, but painfully slooooow to draw a bath of water.

I have a mains pressure unvented hot water tank and it's great. I can fill a bath in a couple of minutes, and have a shower that will knock you into next week. But we have decent water pressure.

Unvented tanks have maintenance responsibilities and obligations, and are supposed to be installed by a plumber with his unvented ticket, but it appears to be like gas, if you are competent, you can DIY your own install (I did)

There is a third option, a "heat store" tank. That's a bit like a hot water tank inside out. The boiler directly heats the water in the tank, and the water in the tank directly heats your radiators. The tank water is fed from a header tank, so it's a vented system so no maintenance issues and you don't need any special qualifications to install it.

But here's the clever bit, the hot water is "instantly" heated by passing through a heat exchange coil in the top of the tank. So from the plumbing point of view it's no different to any mains pressure water piping and no need for expansion vessels and relief valves. But you get hot water at mains pressure.

If your pressure is variable or poor, fit a thermostatic mixer shower with a pump, and you will get a truly decent shower.

I wish I had known about heat store tanks when I built this house, I would have installed that in preference to the unvented tank I have.