New GCH Boiler

Catbells

Our Potterton boiler finally died this week. We need to get a new one for the winter. Its a 10 radiator house on three floors and we'd like to get a combination condensing boiler but have been told the water pressure here isn't high enough for a combi boiler. We aim to get a recommended local Gas engineer in to fit it rather than going through British Gas and will continue with our annual service contract with BG when the warranty on the boiler runs out. I'm not sure on a couple of points.
1. Can we get a condensing boiler without it being a combination boiler? and
2. And can you get a combination condensing boiler all in one (as I suspect)?
3. Can anyone recommend a good quality boiler please.
4. Is there another cheaper but good way to have the boiler checked and serviced rather than going through British Gas for which we pay £18 a month? They only come out once or twice a year for boiler and radiator cover.
THANKS.


We have a water softener so the next boiler will hopefully last for a very long time.

gas4you

Flow rate is more important than water pressure.

You need a minimum of 0.5-0.75 bar pressure, but Ideally the flow should be around 15/16 l/m.

Combi's will work down to 9/10 l/m but the flow out of the hot taps will not be very good.

If you water flow is really bad then look at a condensing normal boiler with a new hot water cylinder.

Your local water authority has to supply at least 9 l/m.

macman

All new install domestic boilers are now by law condensing ones (with very limited exceptions). They are available in combi and conventional versions.
Ask your RGI for their opinion on the make and model following a site inspection, but I would consider Worcester-Bosch, Vaillant, and Viessmann.

Catbells

gas4you wrote: »

Flow rate is more important than water pressure.

You need a minimum of 0.5-0.75 bar pressure, but Ideally the flow should be around 15/16 l/m.

Combi's will work down to 9/10 l/m but the flow out of the hot taps will not be very good.

If you water flow is really bad then look at a condensing normal boiler with a new hot water cylinder.

Your local water authority has to supply at least 9 l/m.

Thanks. Is the flow rate dependent on the in-pipe diameter?

Catbells

A few months ago I was told on this site that a water softener was not good for central heating system on account of the salt in the water - even though the salt is not in the water which flows through the pipes as it removes the lime before it enters the system. Iwas advised to turn off the softener before installation. Other posters said it didnt matter. Now I'm 'here' and about to get a new boiler I would appreciate a final view on this.

gas4you

Yes, the larger diameter pipe from your water meter the greater the flow.

Pressure and flow are not related, in simple terms for what you need to know.