European Taps

[Jock]

I bought a gorgeous bath tap with a single joystick lever for hot and cold water, but I didn't realise that because it's a fancy-schmantzy European thing it doesn't work well on my UK gravity system. So it takes forever to fill the bath with hot water; the hot water merely trickles out.

In the bathroom airing cupboard is a cylinder hot water tank with the cold water tank combined on top of it. The boiler is in the kitchen downstairs.

I'm now replacing the old boiler with a combi boiler, to be installed in the airing cupboard. However, I've read on the FAQs that combi boilers give a very slow flow to the bath.

My question is: Will a combi boiler make my bathroom tap even worse?

Thanks.

[Lurch]

On Sun, 21 Nov 2004 04:59:26 GMT, "Jock" strung together this:

Depends what boiler it is, what you set the hot water flowrate to, what the incoming pressure to the boiler is and how the hot water is piped from the boiler to the outlet of the tap.

If it's a decent flowrate on the boiler then I wouldn't have thought you would see any reduction in flow, when I upgraded my system to a combi the flow was down a little but as it was hotter and continuous I didn't have to wait for the luke warm water to filter through in stages before getting a decent bathful so overall a quicker fill.

[Set Square]

It depends!

Is the cold side of your new tap connected to the mains, and is the flow from that ok?

If so, you can *potentially* get a hot flow from the combi which is similar to your current cold flow, because the combi delivers water at mains pressure.

Your hot flow is currently limited by the low pressure differential due to the cold header not being much higher than the tap, coupled with the flow resistance through the tap itself. With a combi, the flow will be limited only by how fast it can turn cold water into hot water. Make sure you get a boiler with lots of heating capacity.

[Fred]

I am an amateur, but full pro European ;-) Put in a Euro tap in the kitchen in my old house a while ago. Warm alone does not seem to be any better or worse than at a UK tap. Mixing from the tank is difficult because the cold pressure is much stronger, hence limiting the hot water flow by providing a water barrier. That's how I see it at least. We got round by always turning on the hot first, then gradually opening the cold so as not to overpoor the "gravity" system. The weird return stop valves fitted by plumber (UK) to comply with the law (UK - he insisted on this) did not help matters. Maybe you have something like this as well

As for the combi (new house), mixing is easier. Flow rate has been dealt with in so many posts that I do not need to add my amateur knowledge of it. The only point is: if you are UK pro-bathers, then you need a serious combi (flow >20l/min) to compete with a modern tank system.

Fred

[John Rumm]

He may have been right... if the tap was a genuine mixer tap (i.e. it mixed hot and cold in the tap and then delivered warm water out of the one single spout), then you need the double check valve. If the tap was like most mixers these days, where there are two concentric spouts, the mixing (such as it is) happens outside the tap. Hence no need for the valve.