Advice - new boiler (Combi/Unvented)

28 Jan 2007
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United Kingdom
Recently moved house (4 bed/2 bath) and has 10 year old inefficient Potterton system boiler in downstairs utility with a hot water vented cylinder in upstairs airing cupboard and cold water tanks in loft. Hot water pressure is very low (particularly in shower) so investigating options including new boiler or shower pump. Had a couple of quotes but each offered different advice and uncertain how to proceed as no option was expected!

1 - recommended new combi boiler (Worcester Bosch which we had previously and liked) but wants to install into upstairs airing cupboard which is right next to main bedroom instead of in utility room to replace current system boiler. Says best place as easier access to upgrade gas pipes to 22mm(?) from gas meter and locating in utility would mean it would take longer for hot water to get to bathroom. Concerned about noise next to main bedroom though.

2 - recommend an unvented cylinder to increase water pressure throughout house and potentially a new system boiler as current Potterton very inefficient (both Vaillant). Wants to put unvented cylinder into airing cupboard and put new boiler in place of existing boiler in utility. Again concerned by noise from airing cupboard and slightly more expensive in long term as needs both cylinder and boiler eventually even if boiler left for now.

Can anyone comment on noise of an unvented cylinder especially so close to our main bedroom?

Also I have read online the benefits of unvented cylinders but not convinced as always had combi's until recently. Would a combi suffice?

No one recommended a shower pump so wondering if just install one and deal with boilers later as current system is working.
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A combi boiler will supply one outlet. Therefore it you only intend to use one bathroom at a time, won't ever use hot water in the kitchen at the same time someone is in the shower and don't mind waiting 15 minutes while the bath fills, get a combi.

Hot water cylinders do not make noise. Boilers do.
Unvented cylinders are far better than what you have now, but can only be fitted if the incoming pressure and flow are sufficient. These must be measured before any choice of system is made.

A pump will resolve the problem of low pressure and cost far less than any new boiler or cylinder. Pumps are noisy.

Replacing a boiler just because it is 'inefficient' is a total waste of money. It will be 10+ years before any savings in gas cover the cost of the boiler, by which time your new boiler will be a pile of scrap.
Thanks for advice - all sensible points.

We have 16 litres per minute measured from the kitchen sink.

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