Minimum flow rate for a Combi

[masona]

What is the minimum water flow rate Litre/p/m for a combi ?

The reasoning I'm asking is, my sister is having one install today and they have not even tested the flow rate !!!!!!

I'm guessing, is it approx 11 litres per minute ?

 

[weargas]

depends on the make/size of combi. but it's the maximum rate you mean. the minimum is the slowest you can run the tap and still have the boiler kick in. the maximum can be anywhere between 9.5 and 18. what make boiler is it?

 

[masona]

Thanks for that, it's too late now as they are now fitting it, all I know is the combi is a Potterson at the moment.

The ex-boiler Halstead is coming to the end of life, and I'm trying to talk her out of having a combi as they live in a low water pressure area, that why I was asking what is the minimum water pressure to qualified for a combi and if it's suitable.

She is a single parent with 2 young girls with 1 bath and no shower, hot & cold taps in kitchen, cold feed washing machine, 6 radiators.

 

[weargas]

if it's a potterton performa (probably a 24) it's basically the baxi combi range and the flow rate is 9.8 l/min =35° rise. That boiler will operate with a flow rate as low as 2.5 l/min.

 

[ollski]

normally around 1.2 bar incoming mains pressure for hot water side.....check with the manufacturer's instructions there will be a slight variation.

 

[masona]

That boiler will operate with a flow rate as low as 2.5 l/min.

So if you have a flow rate, example of 2.5l/min into the flow side of the boiler, is the the flow rate on the hot return the same or does it slow down further to heat up the water ?

Thanks,