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.

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

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

In a word, dunno!

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.
--

SJW
A.C.S. Ltd
url here when I get around to it
Please reply to group or use 'usenet' in email subject

In an earlier contribution to this discussion,
Jock wrote:

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.

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.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

"Jock" wrote:

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.

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

Fred wrote:

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

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.

--
Cheers,

John.

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