I want to replace some of my rads but am confused about the measurements.
The units I have are quite small and old. The one in my hallway for example
is 600mm wide across the actual body, but 700mm across from the extremity of
each tap/joint/whatever you call it just before where it meets the
T-junction for the house pipes.

Looking on Screwfix, the widths available are 300mm, 500mm and 600mm. It
also seems like those radiators are the same width body as the place where
the pipe would join, unless there's something you screw in that makes up the
distance ..?

I'm confused - what should I be measuring? Also, does anyone have a good
recommendation for a web-guide to replacing rads? I'm going to get help
from a mate putting a new one in where the pipes need cutting, but was
hoping to do straightforward direct replacement myself before going as far
as draining the system.




a

al wrote:
I want to replace some of my rads but am confused about the
measurements.
The units I have are quite small and old. The one in my hallway for
example
is 600mm wide across the actual body, but 700mm across from the
extremity of
each tap/joint/whatever you call it just before where it meets the
T-junction for the house pipes.

Looking on Screwfix, the widths available are 300mm, 500mm and 600mm.
It
also seems like those radiators are the same width body as the place
where
the pipe would join, unless there's something you screw in that makes
up the
distance ..?

The bits that screw in the radiator are part of the valve rather than
being part of the rad so the width you want in your case is 600. When
you put new valves on really make sure they've sealed properly!


I'm confused - what should I be measuring? Also, does anyone have a
good
recommendation for a web-guide to replacing rads? I'm going to get
help
from a mate putting a new one in where the pipes need cutting, but
was
hoping to do straightforward direct replacement myself before going
as far
as draining the system.

Close off the valve at each end, drain the rad in whatever way,
disconnect the valve from the rad at the obvious joint, carefully
remove rad. Now either remove the other part of the rad valve from the
old rad or get a new one and put it in the new rad. Refitting is the
reverse of removal etc.

wrote in message
oups.com...
The bits that screw in the radiator are part of the valve rather than
being part of the rad so the width you want in your case is 600. When
you put new valves on really make sure they've sealed properly!


I took out the radiator today. The only thing "in" the radiator that looks
like I can remove it is about 1cm worth of pipe going into the side of if
(with the locknut around it). Looks like it would probably only extend into
the radiator about another 1-2cm, which is a pretty small amount. Makes me
think a 600mm new one would be too narrow ... however there doesn't appear
to be a 700mm or 650mm standard size.

I've uploaded a couple of (bad!) pics below:

http://www.alanirl.pwp.blueyonder.co.uk/hall1.JPG
http://www.alanirl.pwp.blueyonder.co.uk/hall3.JPG

Sorry about the exposure ... a lot of bright white surfaces taken with a
flash on a cheap camera! The conical parts going into the main radiator
body are fixed parts of it, not removable. Will a 600mm rad really fit with
just those little other bits in it?





a

On Fri, 25 Mar 2005 01:27:47 GMT, "al"
wrote:
however there doesn't appear
to be a 700mm or 650mm standard size.

I've uploaded a couple of (bad!) pics below:

http://www.alanirl.pwp.blueyonder.co.uk/hall1.JPG
http://www.alanirl.pwp.blueyonder.co.uk/hall3.JPG

Sorry about the exposure ... a lot of bright white surfaces taken with a
flash on a cheap camera! The conical parts going into the main radiator
body are fixed parts of it, not removable. Will a 600mm rad really fit with
just those little other bits in it?


if the pipes wont flex enough to fit you can use extenders like:
http://www.screwfix.com/app/sfd/cat/...17552&ts=31399


I'd replace the valves aswell, it looks like the old ones have been
painted over some.

"basil" wrote in message
...
if the pipes wont flex enough to fit you can use extenders like:
http://www.screwfix.com/app/sfd/cat/...17552&ts=31399


I'd replace the valves aswell, it looks like the old ones have been
painted over some.

Are those extenders horizontal pieces that fit directly into the radiator at
one end and the screw-fit face of the vertical heating pipe at the other
(sorry about the nomenclature, no idea what to call these bits!)?

The valves (and pipes) are quite nasty. However I'd have to drain the
system to do that wouldn't I? Think I'll just sand down and re-paint.




a

On Fri, 25 Mar 2005 12:01:00 GMT, "al"
wrote:


Are those extenders horizontal pieces that fit directly into the radiator at
one end and the screw-fit face of the vertical heating pipe at the other
(sorry about the nomenclature, no idea what to call these bits!)?

The ones from Wickes are! The nut on the valve (I think its called 3/4
inch BSP ) which holds the current tail is passed over the new tail
which is then screwed directly to the radiator with some ptfe tape on
the thread. You then screw the nut back to the valve and thats it.
Looking at your pictures I think you probably have the right size nuts
on your valves.

Looking at the screwfix ones I cant make out how they attach.

the one at the bottom of this page looks like the Wickes ones I have;
http://www.toolstation.com/shop/Plum...ves/d20/sd2762


The valves (and pipes) are quite nasty. However I'd have to drain the
system to do that wouldn't I? Think I'll just sand down and re-paint.


I agree...

"basil" wrote in message
...
Looking at the screwfix ones I cant make out how they attach.

the one at the bottom of this page looks like the Wickes ones I have;
http://www.toolstation.com/shop/Plum...ves/d20/sd2762


Speaking of which, I want to get Thermostatic Valves for the upstairs
bedrooms, as they get hot a lot quicker than the ambient temperature
downstairs where the main thermostat is. Any recommendations on good,
reliable makes? I've heard a few stories about some of them getting stuck
on/off and doing buggar all after a while ...




a

On Sun, 27 Mar 2005 23:27:04 GMT, "al"
wrote:


Speaking of which, I want to get Thermostatic Valves for the upstairs
bedrooms, as they get hot a lot quicker than the ambient temperature
downstairs where the main thermostat is. Any recommendations on good,
reliable makes? I've heard a few stories about some of them getting stuck
on/off and doing buggar all after a while ...

I've heard they last 10 years or so. I replaced the old ones here with
this tpe:
http://www.discountedheating.co.uk/s..._4_1251 .html
they work, and no noise like with some.

Of course it means a drain down and you may have to replace the old
olive. I think very old valves have an imperial thread even. While
your doing this you could re-plumb the new rad so you dont need
extenders.

Basil

On Sun, 27 Mar 2005 23:27:04 GMT, "al"
wrote:

"basil" wrote in message
.. .
Looking at the screwfix ones I cant make out how they attach.

the one at the bottom of this page looks like the Wickes ones I have;
http://www.toolstation.com/shop/Plum...ves/d20/sd2762


Speaking of which, I want to get Thermostatic Valves for the upstairs
bedrooms, as they get hot a lot quicker than the ambient temperature
downstairs where the main thermostat is. Any recommendations on good,
reliable makes? I've heard a few stories about some of them getting stuck
on/off and doing buggar all after a while ...


I've always used Invensys/Drayton TRV4s and had good results. In
general, I think that you could expect good behaviour from any of the
branded products like Honeywell or Pegler.

It's generally reckoned that the heads have a life of about 7 years.
I've never had less than about 12 from a TRV4 so am pretty happy with
them.

It is important in any case to have a clean system, so while you are
doing replacements, it is worth giving the system a thorough flushing
and filling with corrosion inhibitor.



--

..andy

To email, substitute .nospam with .gl

"basil" wrote in message
news
I've heard they last 10 years or so. I replaced the old ones here with
this tpe:
http://www.discountedheating.co.uk/s..._4_1251 .html
they work, and no noise like with some.

Of course it means a drain down and you may have to replace the old
olive. I think very old valves have an imperial thread even. While
your doing this you could re-plumb the new rad so you dont need
extenders.

Unfortunately, the original rad in question wasn't one of the ones I was
thinking of putting a TRV on! Those ones you've pointed out sure do look
nice, but cost a bit! Most of the ones I've seen on Screwfix, etc. seem to
be in the £5-10 range. Is the extra money for style or function?




a

"Andy Hall" wrote in message
...
I've always used Invensys/Drayton TRV4s and had good results. In
general, I think that you could expect good behaviour from any of the
branded products like Honeywell or Pegler.

It's generally reckoned that the heads have a life of about 7 years.
I've never had less than about 12 from a TRV4 so am pretty happy with
them.

It is important in any case to have a clean system, so while you are
doing replacements, it is worth giving the system a thorough flushing
and filling with corrosion inhibitor.


And when they fail ...?




a

On Mon, 28 Mar 2005 22:28:15 GMT, "al"
wrote:

"Andy Hall" wrote in message
.. .
I've always used Invensys/Drayton TRV4s and had good results. In
general, I think that you could expect good behaviour from any of the
branded products like Honeywell or Pegler.

It's generally reckoned that the heads have a life of about 7 years.
I've never had less than about 12 from a TRV4 so am pretty happy with
them.

It is important in any case to have a clean system, so while you are
doing replacements, it is worth giving the system a thorough flushing
and filling with corrosion inhibitor.


And when they fail ...?




a



If you mean the radiators, then it was probably because inhibitor
wasn't used.

If you mean the TRVs, then making sure that the system is and remains
clean means that the plungers in the valve bases are less likely to
stick. Thus, when the heads do eventually go, it may well be
possible to just replace those.

I've found that the failure mode of the heads is generally that they
become hard on or off with no control in between.



--

..andy

To email, substitute .nospam with .gl

On Mon, 28 Mar 2005 10:26:30 +0100, Andy Hall wrote:

On Sun, 27 Mar 2005 23:27:04 GMT, "al"
wrote:

"basil" wrote in message
. ..
Looking at the screwfix ones I cant make out how they attach.

the one at the bottom of this page looks like the Wickes ones I have;
http://www.toolstation.com/shop/Plum...ves/d20/sd2762


Speaking of which, I want to get Thermostatic Valves for the upstairs
bedrooms, as they get hot a lot quicker than the ambient temperature
downstairs where the main thermostat is. Any recommendations on good,
reliable makes? I've heard a few stories about some of them getting stuck
on/off and doing buggar all after a while ...


I've always used Invensys/Drayton TRV4s and had good results. In
general, I think that you could expect good behaviour from any of the
branded products like Honeywell or Pegler.

IME this is one of the few products which goes against the usual wisdom of
you pay for what you get. I have found that the cheap TRVs seem to last
longer and go on operating longer. Whilst the ACL Drayton units seem to be
the priciest and shortest lived. Furthermore I have found them to be more
flow direction sensitive (whilst claiming bi-direction).

However this is not reason to set aside you-pay-for-what-you-get just yet,
except in this matter.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://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

Well Ed, I found the opposite !

In a sample of 5 cheap TRVs from B and Q, costing about £5 each, 3 failed
within a couple of months - I took them back with the receipt to get them
replaced and they had stopped selling them - "too many returns" the resident
plumber bloke said....

So I had to get some more expensive ones at about £9 each - problem was they
were a different size and the plumbing was well bedded in to the wall, so I had
to dig out the wall to modify, then make good the wall. The replacements are
still going well after two years.

I vowed to myself that I would only buy the better ones (not cheapest) from now
on.

Nick

"nick smith" wrote in message
...
So I had to get some more expensive ones at about £9 each - problem was
they
were a different size and the plumbing was well bedded in to the wall, so
I had
to dig out the wall to modify, then make good the wall. The replacements
are
still going well after two years.

I vowed to myself that I would only buy the better ones (not cheapest)
from now
on.

That's still about £6 cheaper than the TRV4's though. Suppose it depends on
how many I go for. In one bedroom, there are two small double rads. Might
put a TRV on one and not the other. Usually I only use one rad unless it's
exceptionally cold so that should work. Might put one in the hall, but not
anywhere else downstairs as the thermostat is in the sitting room/lounge.




a