Looking for some plumbing advice/options for a house I’m in the process of buying and trying to work out the best route to modernise the water system.
Current setup:
- Water flow tested around 9L/min
- Thames Water minimum guaranteed pressure is 1 bar
- Existing gravity-fed system
- Boiler is heating-only (fairly new from what I understand)
- Cold water storage tank in the attic
- Hot water cylinder currently in airing cupboard
- 1 upstairs bathroom with:
- electric shower
- toilet
- sink
- Downstairs cloakroom with small sink + toilet
- Kitchen + utility taps are already mains fed
What I’d ideally like:
- Remove the cold water storage tank entirely
- Have the house fully mains fed if possible
- Replace the bath with a walk-in shower only
- Happy for the shower to either:
- stay electric
- become thermostatic/mains fed
- Improve overall pressure/flow consistency
I’m open to:
- unvented cylinder
- combi boiler
- accumulator tank
- whole house booster pump
- upgrading incoming main from 15mm to 25mm
- basically anything sensible that doesn’t involve summoning Poseidon directly
The bit I’m struggling with is what is realistically viable with a 9L/min supply.
Some people have said:
- “9L/min is hopeless for an unvented system”
- others said a pump/accumulator massively improved things
- and some suggested the restriction may actually be internal pipework rather than the incoming supply itself
Would love to hear:
- what you’d do in this situation
- what setup you’d personally choose
- whether it’s worth investigating the incoming main upgrade first
- and what order you’d tackle everything in
Thank you ❤️