Acceptable mains flow rate for combi boiler installation

[richard44]

Hi,

I'm looking to have a new boiler fitted, and I'm struggling to decide whether to go for a combi boiler or stick with my conventional heating system (hot water cylinder etc.) and just replace the boiler.

I'm tempted by a combi in the sense that it will mean I don't have to store a large amount of hot water (which I rarely use) yet still get a decent shower. However, I'm concerned that my mains water flow rate is not going to be good enough for a combi system, or at least to get good performance out of it. The best I can get out of any outlet (I've tried them all!) is 10l/min. I've not measured the static pressure yet, I guess could be the next step. I've checked the stop-cocks etc, the rising main looks to be 1/2" copper pipe, and I'm not in an area known for low water pressure.

I've had various plumbers round to quote, and so far it's about a 50:50 split between those who say it's not a problem and a combi will be fine and those who say it's not worth the risk!

Can anyone give me any guidance on whether 10l/min is ok/bad/terrible as a mains flow rate for starters, and whether you think it'd be ok for a combi boiler?

All advice much appreciated.

Thanks,
Richard

 

[newbie1]

dont take the chance the plumbers that are saying that should be fine wont pop back round when your finished
combis are fine and have their place but personally i would stick with the system you have
prob cheaper as well re boiler and fitting

 

[unguided1]

as newbie1 has stated combis have their place if you live in a small house or flat with one bathroom and not many people living there then fine have a combi, if you have more than one bathroom then forget a combi.

they can be more trouble in the long term than they are worth

 

[stevetheplumber]

flow rate can be dependant on many things can you get 10litres a minute from all the taps simultaneously or is it 10 litres from one and the others stop remember your testing only taps fed from the mains usually just the wasing machine cold sink cold and an outside tap
have your neibours got combis is also a good sign

 

[richard44]

10l/min is about the best I can get as a combined flow rate from several cold taps. Frustratingly I gather the water authority have to deliver a minimum of 9l/min, so I guess I might be stuck with it.

I'm guessing you'd normally expect much better than this?

Cheers,
Richard