I want to replace a bypass valve in the central heating. It's easily
accessible and uses 22mm copper pipe with compression fittings.

I don't want the bother of draining, refilling, bleeding, adding
inhibitor etc, so how well does freezing work? I've never done it or
even seen it done, but £17 from Screwfix seems reasonable if it works.


Cheers
--
Clive

On Sat, 16 Feb 2019 17:11:08 +0000, Clive Arthur
wrote:

I want to replace a bypass valve in the central heating. It's easily
accessible and uses 22mm copper pipe with compression fittings.

I don't want the bother of draining, refilling, bleeding, adding
inhibitor etc, so how well does freezing work? I've never done it or
even seen it done, but £17 from Screwfix seems reasonable if it works.


Cheers
You might find that you need 2 cans of freezer for 2 sections of 22mm
pipe (ie. either side of the bypass valve). There's a user comment to
this effect on the Screwfix page, but also comments that it works ok.
Let the system cool right down before use.

On 16/02/2019 17:11, Clive Arthur wrote:
I want to replace a bypass valve in the central heating.Â* It's easily
accessible and uses 22mm copper pipe with compression fittings.

I don't want the bother of draining, refilling, bleeding, adding
inhibitor etc, so how well does freezing work?Â* I've never done it or
even seen it done, but £17 from Screwfix seems reasonable if it works.

Depending on the location and how easy the pipe is to work on, you might
be able to do it "live"...

Make sure the system is off and cool. If its a vented system then stick
bungs into the F7E pipe out the bottom of the header tank, and also the
vent pipe. If its a pressurised system then drain off a few litres to
drop the pressure to "not pressurised". Shut off the existing bypass so
that you get no or as little flow as possible through it.

Have a 22mm service valve ready with its back nut taken off, loosen the
existing one, while keeping the fitting pushed against the olive. The in
a quick motion, pull the joint apart and then slap the valve on, and
tighten quickly. Having a spare hand available to stick their thumb over
the end of the bypass might be handy. Repeat for the other end. You now
have a couple of valves you can attach to the new bypass at your leisure.

Have some old towels wrapped about to catch any spillage.

IME you can normally end up spilling less than a half cup full of water.


--
Cheers,

John.

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On 17/02/2019 00:04, John Rumm wrote:

You now
have a couple of valves you can attach to the new bypass at your leisure.

Except the space taken up by the original bypass it now full of your new
valves.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 17/02/2019 01:49, alan_m wrote:
On 17/02/2019 00:04, John Rumm wrote:

You now have a couple of valves you can attach to the new bypass at
your leisure.

Except the space taken up by the original bypass it now full of your new
valves.

Which you can stick an elbow in and carry on in a different direction.


--
Cheers,

John.

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

If there is a substance in the water, then its freezing point is going to be
lower.
Also you might need to be very quick to get it done, no room for problems
once the pipe is cut.
Brian

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"Davidm" wrote in message
...
On Sat, 16 Feb 2019 17:11:08 +0000, Clive Arthur
wrote:

I want to replace a bypass valve in the central heating. It's easily
accessible and uses 22mm copper pipe with compression fittings.

I don't want the bother of draining, refilling, bleeding, adding
inhibitor etc, so how well does freezing work? I've never done it or
even seen it done, but £17 from Screwfix seems reasonable if it works.


Cheers
You might find that you need 2 cans of freezer for 2 sections of 22mm
pipe (ie. either side of the bypass valve). There's a user comment to
this effect on the Screwfix page, but also comments that it works ok.
Let the system cool right down before use.

On 17/02/2019 02:50, John Rumm wrote:
On 17/02/2019 01:49, alan_m wrote:
On 17/02/2019 00:04, John Rumm wrote:

You now have a couple of valves you can attach to the new bypass at
your leisure.

Except the space taken up by the original bypass it now full of your
new valves.

Which you can stick an elbow in and carry on in a different direction.


It's a right angled valve unfortunately.

Cheers
--
Clive