2.2 Bar mains and poor flow rate, combi system.

[Thegift]

Hi chaps recently brought a new house average 3 bed terraced.

Had a back boiler with cylinder ripped it all out with all new pipework and rads and got my mate to fit a cdi 32kw compact in the loft as I'm not GSR yet as I mainly do maintenance and bathrooms.

anyway I'm finding the pressure on the hot to be quite poor.

Hot water: 9 litres per min from kitchen taps.

cold water: 16 litres per min from kitchen taps.

cold water mains BAR pressure is 2.2BAR standing and 1.75BAR with cold tap on full flow.

Is this just a case of ok pressure but poor flow? Main incoming is Black LDPE 3/4 I think black rubber used a lot in the 60's 70's I believe, the stopcock is new and on full. Can't be doing with the hassle of changing it as it runs throughout the house under concrete. As the boiler is in the loft I'm guessing this doesn't help as the mains will loose pressure running into the loft?

anything I could do to increase this? Did think about a home boost pump but would be pointless as due to water regs can only boost up to 12lpm. About to fit the bathroom next month with a thermostatic shower but got a feeling I'm going to be disappointed with the pressure!

 

[Dotty]

Accumulator.

GAH - How Coldstream Works

 

[Thegift]

Accumulator.

GAH - How Coldstream Works

Ive heard about Accumulators before but never fitted one, easy enough to do? Cost wise what would I be looking at? And ok to fit in loft near the combi?

 

[Destroyer2813]

Have you checked against the manual to see what the ltr min the cdi puts out

 

[Ermintrude]

Too of head 32kw 13l at 35 rise? Attach filling loop to hose and measure flow rate and pressure at boiler, might have an obstruction. 9lpm at kitchen tap is ample it's the bathroom you may get upset with.

 

[bright spark]

I wonder is there a filter on the mains inlet to the boiler. May be dirty causing an obstruction restricting flow rate.

 

[AWheating]

Mixer tap? Prob working ok by the sound of it. What's the hot water flow rate at the bath?

Id be surprised if you have a problem apart from a slight misunderstanding of what to expect.