Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the system
for fear of what it may do or damage may be done.

"Adam Topp" wrote in message
m...
Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the system
for fear of what it may do or damage may be done.

Adam,

There are two types of heated towel rail, those for connection to the
central heating radiator circuit and those for connection to the hot water
system (as long as this is circulated by a suitable pump).

The logic for connecting to the hot water system is that you may want your
towels heated even when the heating is off in the summer. Because new water
is going through the hot water system whenever a tap is run, you need a
brass towel rail for connection to that circuit - the new water has lots of
air in it which would rust a steel towel rail.

It sounds like you have a steel towel rail, which is intended for connection
to the central heating radiator circuit. I think that this is what they mean
by a closed system, as the same radiator water circulates all the time, and
apart from leaks it is not replenished. This is not really affacted by
whether there is an open expansion tank on the system or it is a completely
sealed system with a pressure vessel. The expansion tank may allow
marginally more air into the system, but this should be minimal if the
system is working properly. Let's hope it is, because your radiators are all
made out of steel, and they will rust just as quickly as the towel rail!

I'm not 100% certain about this, but 'pretty sure'! Perhaps someone else can
confirm.

Geoff

Adam Topp wrote:

Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the system
for fear of what it may do or damage may be done.

The instructions may be not so much about open or vented but rather
meaning it has to be used on a circuit rather than in the supply to the
HW taps.

On flats in North London built between the wars you will often find that
the towel rail is in series with the supply to the HW taps. The
radiators are made of brass throughout. This is for flat swith
_central_ heating in the true sense of the word. I.e. Industrial
boiler(s) supplying heating and HW through out the building.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett" wrote in message
...
Adam Topp wrote:

Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the system
for fear of what it may do or damage may be done.

The instructions may be not so much about open or vented but rather
meaning it has to be used on a circuit rather than in the supply to the
HW taps.

On flats in North London built between the wars you will often find that
the towel rail is in series with the supply to the HW taps.

I have always assumed that this only works in systems where the hot water is
recirculated. Is that right?


The
radiators are made of brass throughout. This is for flat swith
_central_ heating in the true sense of the word. I.e. Industrial
boiler(s) supplying heating and HW through out the building.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

GB wrote:

"Ed Sirett" wrote in message
...
Adam Topp wrote:

Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the system
for fear of what it may do or damage may be done.

The instructions may be not so much about open or vented but rather
meaning it has to be used on a circuit rather than in the supply to the
HW taps.

On flats in North London built between the wars you will often find that
the towel rail is in series with the supply to the HW taps.

I have always assumed that this only works in systems where the hot water is
recirculated. Is that right?

It can be I guess, but in summer the radator gets hot by the draw off of
DHW not by any pumps.

"Ed Sirett" wrote in message
...
GB wrote:

"Ed Sirett" wrote in message
...
Adam Topp wrote:

Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the
system
for fear of what it may do or damage may be done.

The instructions may be not so much about open or vented but rather
meaning it has to be used on a circuit rather than in the supply to
the
HW taps.

On flats in North London built between the wars you will often find
that
the towel rail is in series with the supply to the HW taps.

I have always assumed that this only works in systems where the hot
water is
recirculated. Is that right?

It can be I guess, but in summer the radator gets hot by the draw off of
DHW not by any pumps.

In our house we circulate the hot water summer and winter, as one or two of
the taps are a long and convoluted pipe run from the hot water cylinder. In
a block of flats they would _have_ to do that.

GB wrote:

"Ed Sirett" wrote in message
...
GB wrote:

"Ed Sirett" wrote in message
...
Adam Topp wrote:

Hi,

I have just acquired a heated towel rail, which, when looking at the
spec. is designed apparently for use on a closed system only. Our
system is open vented. What is the difference between a radiator
designed for use on a closed system as opposed to an open one. I
cannot see much difference but I'm now loathe to put it on the
system
for fear of what it may do or damage may be done.

The instructions may be not so much about open or vented but rather
meaning it has to be used on a circuit rather than in the supply to
the
HW taps.

On flats in North London built between the wars you will often find
that
the towel rail is in series with the supply to the HW taps.

I have always assumed that this only works in systems where the hot
water is
recirculated. Is that right?

It can be I guess, but in summer the radator gets hot by the draw off of
DHW not by any pumps.

In our house we circulate the hot water summer and winter, as one or two of
the taps are a long and convoluted pipe run from the hot water cylinder. In
a block of flats they would _have_ to do that.

Sure, the DHW is drawn from a pumped circuit - my point which I did not
make clear was that (on the flats i've seen anyway) the towel warmer is
not part of that circuit but leads to the HW taps from that circuit.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html