Combination boiler-insufficient water pressure

I am looking to get rid of a 26 year old gas boiler and cylinder and would like to have a combination boiler installed in it's place. My water pressure is quite low. I have had a pressure gauge fitted which is reading about 2.5bar 95% of the time but flickers and has dropped as low as 1.8 at peak times. Are my dreams of losing the cylinder going to remain just that?

1.8 bar should be fine, assuming this is working pressure? IE is it the pressure in your house with a tap switched on? If not, what is that pressure? Are you sure a combi is really what you need if you've got a cylinder at the moment? How many baths/showers/basins do you have?

Hello muggles. I will check to the pressure with taps running later but the reason i wanted to get rid of the cylinder was twofold:- gain a cupboard space in a very small flat and I was under the impression that combination boilers once installed would save me cash due to their being more energy efficient. Is this correct?

Condensing boilers are more energy efficient, Combination boilers are one type of condensing boiler but all new domestic boilers in the UK are now condensing, and the efficiency difference between combi's, system boilers and heat-only boilers (your present one is probably a heat-only) is negligible. Just make sure your installer fits a SEDBUK Band A boiler and you'll be fine. Expect to pay a bit more for a decent one, I wouldn't recommend going for the cheapest you can find, there's lots of info on these forums about which makes are good and which are not so good.

Combi boilers are not the be-all and end-all by any means - lower-powered ones tend to give very poor hot water flow rates, higher-powered ones improve this but are not necessarily the answer as they may be over-rated for your heating system. Also if it breaks down then you will have no hot water until it's fixed, as there's generally no storage (unless you go for a storage combi, which works slightly differently).

EDIT: Having said all that, as you live in a small flat, a combi would almost certainly be your best option, as it's unlikely you'll have a high hot water demand

roscop said:

Hello muggles. I will check to the pressure with taps running later but the reason i wanted to get rid of the cylinder was twofold:- gain a cupboard space in a very small flat and I was under the impression that combination boilers once installed would save me cash due to their being more energy efficient. Is this correct?

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You should set the kitchen or garden tap (s) to give a flow rate of 12 litres per minute. Add two together if necessary.

Then see the pressure remaining in the supply on the gauge. If its over 0.5 bar then the system should work fine.

Be aware that with a combi you can unly use one tap outlet normally at a time.

Tony