We've just got the keys back to our house, after a couple of years in a
camper van whilst friends lived here. We've noticed something very
strange has happened with the boiler - the hot water's coming through FAR
too fast, so it's running cold. If you turn the tap way down, the flow
comes back to where it always used to be, and the temperature gets back
to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking over.
A couple of years ago, a leak meant it had a new heat exchanger fitted.

Before I go ringing British Gas (it's under a maintenance contract), is
there anything obvious I can check or poke?

Ta,
A.

Adrian wrote:
We've just got the keys back to our house, after a couple of years in a
camper van whilst friends lived here. We've noticed something very
strange has happened with the boiler - the hot water's coming through FAR
too fast, so it's running cold. If you turn the tap way down, the flow
comes back to where it always used to be, and the temperature gets back
to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking over.
A couple of years ago, a leak meant it had a new heat exchanger fitted.

Before I go ringing British Gas (it's under a maintenance contract), is
there anything obvious I can check or poke?

Ta,
A.

I suspect that the flow through the boiler was always limited by a stopcock
somewhere (maybe the main incomer) and your friends (or a plumber) has
opened it up fully after fitting the new heat exchanger.

Look for the stopcock supplying the combi and try shutting it down until
you get back to your old flow rate.

Tim

Tim+ wrote:
Adrian wrote:
We've just got the keys back to our house, after a couple of years
in a camper van whilst friends lived here. We've noticed something
very strange has happened with the boiler - the hot water's coming
through FAR too fast, so it's running cold. If you turn the tap way
down, the flow comes back to where it always used to be, and the
temperature gets back to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking
over. A couple of years ago, a leak meant it had a new heat
exchanger fitted.

Before I go ringing British Gas (it's under a maintenance
contract), is there anything obvious I can check or poke?

Ta,
A.

I suspect that the flow through the boiler was always limited by a
stopcock somewhere (maybe the main incomer) and your friends (or a
plumber) has opened it up fully after fitting the new heat exchanger.

Look for the stopcock supplying the combi and try shutting it down
until you get back to your old flow rate.

I agree. And it could be a simple as an isolation valve just before the
boiler.

--
Adam

On Mon, 4 Feb 2013 22:36:20 -0000, "ARW"
wrote:

Tim+ wrote:
Adrian wrote:
We've just got the keys back to our house, after a couple of years
in a camper van whilst friends lived here. We've noticed something
very strange has happened with the boiler - the hot water's coming
through FAR too fast, so it's running cold. If you turn the tap way
down, the flow comes back to where it always used to be, and the
temperature gets back to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking
over. A couple of years ago, a leak meant it had a new heat
exchanger fitted.

Before I go ringing British Gas (it's under a maintenance
contract), is there anything obvious I can check or poke?

Ta,
A.

I suspect that the flow through the boiler was always limited by a
stopcock somewhere (maybe the main incomer) and your friends (or a
plumber) has opened it up fully after fitting the new heat exchanger.

Look for the stopcock supplying the combi and try shutting it down
until you get back to your old flow rate.

I agree. And it could be a simple as an isolation valve just before the
boiler.

Isn't that boiler one that has a frame you put up and plumb then drop
the boiler into?

If so it has a full set of quarter turn taps on the frame at the
bottom front plate.

On Mon, 04 Feb 2013 21:15:21 +0000, Tim+ wrote:

I suspect that the flow through the boiler was always limited by a
stopcock somewhere (maybe the main incomer) and your friends (or a
plumber) has opened it up fully after fitting the new heat exchanger.

Look for the stopcock supplying the combi and try shutting it down until
you get back to your old flow rate.

I like that idea. It's nice and simple.

I shall rummage.

Adrian wrote:
We've just got the keys back to our house, after a couple of years in
a camper van whilst friends lived here. We've noticed something very
strange has happened with the boiler - the hot water's coming through
FAR too fast, so it's running cold. If you turn the tap way down, the
flow comes back to where it always used to be, and the temperature
gets back to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking
over. A couple of years ago, a leak meant it had a new heat exchanger
fitted.

Before I go ringing British Gas (it's under a maintenance contract),
is there anything obvious I can check or poke?

Isn't there a temp setting on the boiler for water? - they've probably
turned this right down if they had children or elderly people living there

On Mon, 04 Feb 2013 21:23:55 +0000, Phil L wrote:

Isn't there a temp setting on the boiler for water? - they've probably
turned this right down if they had children or elderly people living
there

Yes, there is - and it's turned up. When you turn the tap flow down, the
water is proper hot.

Adrian wrote:
We've just got the keys back to our house, after a couple of years in
a camper van.

BTW Did you have a good holiday then?

--
Adam

On Mon, 04 Feb 2013 23:12:29 +0000, ARW wrote:

Adrian wrote:
We've just got the keys back to our house, after a couple of years in a
camper van.

BTW Did you have a good holiday then?

Utterly wonderful, ta. 22 countries, including Tunisia, Albania, Serbia,
Bosnia...

On 04/02/2013 20:55, Adrian wrote:
We've just got the keys back to our house, after a couple of years in a
camper van whilst friends lived here. We've noticed something very
strange has happened with the boiler - the hot water's coming through FAR
too fast, so it's running cold. If you turn the tap way down, the flow
comes back to where it always used to be, and the temperature gets back
to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking over.
A couple of years ago, a leak meant it had a new heat exchanger fitted.

Before I go ringing British Gas (it's under a maintenance contract), is
there anything obvious I can check or poke?

Well what you describe is normal operation for many combis (unless they
include a flow regulator). In these cases one normally throttles the
water supply rate with the inlet service valve, and makes final
temperature adjustment with the taps at the point of use.

(in this weather, you won'y be able to get more than 9 lpm of usably hot
water out of a 24kW boiler).

With many boilers the temperature control for the hot water simply sets
the maximum temperature - it can't set a minimum temp.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 04/02/2013 20:55, Adrian wrote:
We've just got the keys back to our house, after a couple of years
in a camper van whilst friends lived here. We've noticed something
very strange has happened with the boiler - the hot water's coming
through FAR too fast, so it's running cold. If you turn the tap way
down, the flow comes back to where it always used to be, and the
temperature gets back to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking
over. A couple of years ago, a leak meant it had a new heat
exchanger fitted. Before I go ringing British Gas (it's under a
maintenance
contract), is there anything obvious I can check or poke?

Well what you describe is normal operation for many combis (unless
they include a flow regulator). In these cases one normally throttles
the water supply rate with the inlet service valve, and makes final
temperature adjustment with the taps at the point of use.


(in this weather, you won'y be able to get more than 9 lpm of usably
hot water out of a 24kW boiler).

It's snowing here ATM:-)

--
Adam

On Mon, 04 Feb 2013 23:57:18 +0000, John Rumm wrote:

(in this weather, you won'y be able to get more than 9 lpm of usably hot
water out of a 24kW boiler).

Trust me, we're getting FAR more than that with the hot tap full open.

On Tue, 5 Feb 2013 08:30:12 +0000 (UTC), Adrian wrote:

(in this weather, you won'y be able to get more than 9 lpm of usably
hot water out of a 24kW boiler).

Trust me, we're getting FAR more than that with the hot tap full open.

Make your mind up:

" ... the hot water's coming through FAR too fast, so it's running cold.
If you turn the tap way down, the flow comes back to where it always
used to be, and the temperature gets back to hot."

So is this high flow of water "useably hot" or not?

--
Cheers
Dave.

On 05/02/2013 08:30, Adrian wrote:
On Mon, 04 Feb 2013 23:57:18 +0000, John Rumm wrote:

(in this weather, you won'y be able to get more than 9 lpm of usably hot
water out of a 24kW boiler).

Trust me, we're getting FAR more than that with the hot tap full open.

Well to quote Scotty, "yea cannea change the laws of physics!", so if
its coming out much faster, than that, its not going to be hot. Which
brings us back to your original problem.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Mon, 04 Feb 2013 20:55:42 +0000, Adrian wrote:

We've just got the keys back to our house, after a couple of years in a
camper van whilst friends lived here. We've noticed something very
strange has happened with the boiler - the hot water's coming through
FAR too fast, so it's running cold. If you turn the tap way down, the
flow comes back to where it always used to be, and the temperature gets
back to hot.

It's a Worcester Bosch 24CDi Combi, just prior to condensing taking
over.
A couple of years ago, a leak meant it had a new heat exchanger fitted.

Before I go ringing British Gas (it's under a maintenance contract), is
there anything obvious I can check or poke?

Ta,
A.

Been watching this for a while.

Isn't a tap an analogue rather than a digital device?

So what is the problem with turning the tap on just enough to get the
water temperature that you want?

Cheers

Dave R

On Tuesday, February 5, 2013 11:25:00 AM UTC, David.WE.Roberts wrote:
snip
Isn't a tap an analogue rather than a digital device?

So what is the problem with turning the tap on just enough to get the
water temperature that you want?

If there's any length of pipe between the boiler and the tap the lag between changing the flow and observing the new temperature makes it quite a long process to get the temperature you want - if there's a flow restrictor upstream that you can set just the once it makes things easier.