Big water flow difference downstairs/upstairs- combi concerns

[ashtons99]

Out of interest and before I get a combi boiler fitted I thought I would do a laymans measurement of water flow in the house.

By no means scientific or a dynamic measurement, I used a 2 litre container and timed filling.

Kitchen tap was 6 seconds so around 20 litres minute

I then did the same at the bathroom tap and found it took around 25 seconds to fill the container ie less than 5 litres min

I did the same in the loft on the ball valve outlet to the header tank, again 25 secs to fill 2 litres.

This is causing me some concern, we we having the existing boiler (gravity system, mounted in kitchen) replaced with a combi 33 or 40kw fitted upstairs in the airing cupboard.

From my basic flow calculations it doesn't seem either of these would be fully serviced by the current flow rate upstairs.

Am I missing something here or do I need to rethink the boiler options ?

 

[muggles]

Is your bathroom tap opening fully, or do you need a new washer in it? Does it have flexible connections or a partly-closed isolation valve that might be providing a restriction? Is it definitely fed from the mains rather than the loft tank?

Your ball valve in the loft has an inlet orifice that is approx 2mm in diameter, so the flow rate out of that is never going to be spectacular

 

[ashtons99]

After posting I thought about it and recalled that I fitted new taps a few years ago which seemed to slow the flow drastically, I think they were something with some sort of ceramic internals. Likewise I thought about the ball valve and the potential restrictions therein. Think I will leave it to my plumber !