New flat - new boiler, advice needed

[tostaky]

We are in London, 1st and 2nd floor flat (conversion).
Low pressure as in when kids are running the bath, there's no hot water in the kitchen.
We are re-doing everything in the flat (very old and dated).
The plumber who works with the builder recommends a pump (to get better pressure) and a boiler with a tank integrated.
One bathroom, one shower room, two toilets, 2 adults and 3 small kids.

Ive read in a magasine that a boiler with an integrated tank was for big houses. A boiler with a tank on the side for a medium + size of household and a standard combi boiler for "normal household" ie 2 adults, 2 kids one bath one toilet.

What size is your family?
How many bathroom/showers/toilets do you have
Whittle of boiler do you have
What make is it?
Are you happy.
If you have a pump on the main, how noisy it is, what make is it and are you happy with it?

Thank you!!!!

yes, I do mean the combi to supply the shower at mains pressure. Everything else can be fed from the cold tank and the hot cylinder, to prevent it sharing flow with the shower. This is a scheme more common in the larger house with two or more bathrooms and a drencher shower. You will also have a cold drinking-water tap in the kitchen, straight off the mains, and preferably with constricted flow to protect the shower flow (possibly this is how your kitchen tap already works as you mentioned it has low flow)

So you can have a pump fitted on the mains to bring your water up to 12 litres per min - that's really interesting - thank you.

It is liable to have undesirable effects though - if it pumps to the shower, and you open another tap, not only will no water come out of the second tap, but air will be sucked in, and get into the pipes.

If the supply pipe is shared with other flats, a pump in one may prevent supply to others.

It is liable to have undesirable effects though - if it pumps to the shower, and you open another tap, not only will no water come out of the second tap, but air will be sucked in, and get into the pipes.

If the supply pipe is shared with other flats, a pump in one may prevent supply to others. The suction may draw dirt or contamination into the drinking water, which is extremely undesirable. Hoses or fittings in contact with water, such as a shower head, a bidet tap or a garden hose, will draw in dirty water, as can a WC cistern valve if not of a modern or special type and correctly fitted.

piglet - my dad said the same, a water tank + a boiler. so i will go for that then!

thank you

Thanks for the pump tips. I'm guessing that a pump which increases supply to 12l per min is probably not hugely strong in the general scheme of things so I'm surprised you think the 'side effects' could be so serious.

Surely any dirt or contamination it would draw in has to be in the supply already? It's just pulling the same water out of the same pipes after all.

Particularly in circumstances where say a ground floor flat has for example 14 litres per min, a mid floor, 10 litres per min and a top floor 8 litres per min, surely as the pump 'pulls' the supply up to the top flat the water is not sucked from the other flats - I don't think that would be permitted by the water board abd would guess that's why they limit suction to 12 litres per min.

There's probably a complex formula behind all this.