I currently have a Potterton 16/22 boiler driving the central heating
via a pumped circuit, and the hot water cylinder via convection.

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

I have basic plumping skills that have amounted to moving the odd
radiator and fitted a new bathroom. The theory of what needs to happen
sounds fairly straight forward, but is this a job I should be tackling
myself, or should I leave it to the experts?

Does anybody have any references/links to information on the details of
what is involved?

Thanks,

don

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

Yes. You need to decide whether you are going to pump the existing gravity
circuit, or convert the system to an S-Plan or Y-Plan zone valve type system
and use the old gravity circuit just for feeding and venting. You'll find
loads about this within this newsgroup using Google.

Christian.

In an earlier contribution to this discussion,
don wrote:

I currently have a Potterton 16/22 boiler driving the central heating
via a pumped circuit, and the hot water cylinder via convection.

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

I have basic plumping skills

Kinky g

that have amounted to moving the odd
radiator and fitted a new bathroom. The theory of what needs to happen
sounds fairly straight forward, but is this a job I should be tackling
myself, or should I leave it to the experts?

Does anybody have any references/links to information on the details
of what is involved?

Thanks,

don

Does your loft have lots of headroom? Assuming that you're not going for a
mains pressure hot water system, you'll need to get your cold header tank
*above* the level of the hot cylinder. This will need supporting *very*
well - water is heavy stuff!

If you're going fully pumped with a single pump, you'll need both HW and CH
to share a common flow pipe until after the pump - where the circuits then
split using zone valves (S-Plan) or a 3-port mid-position valve (Y-Plan).
[See http://content.honeywell.com/uk/homes/systems.htm] If you currently
have separate circuits (4 pipes into the boiler) this will need changing.

If your boiler can stand it, you might consider converting to a non-vented
(sealed) primary circuit - using a pressure vessel and filling loop, and
getting rid of your small F&E tank.
--
Cheers,
Set Square
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"Set Square" wrote in message
...
In an earlier contribution to this discussion,
don wrote:

I currently have a Potterton 16/22 boiler driving the central heating
via a pumped circuit, and the hot water cylinder via convection.

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

From installation in 1973 my ground-floor wall-hung
Potterton 10-16 has been driving 28mm 'gravity'
pipes up to an indirect ho****er cylinder in the loft.
I'd guess the total height is 2 x 8'6" plus ceiling gaps
say ~20 feet? The pipes also have a number of kinks
as the heater is on an external wall and the tank is
about fifteen feet into the centre-line of the house.
As others have stated the cold water tank is mounted
on an over-engineered timber structure towards
the centre of the roof. Water is heavy.

--
Brian

"Brian Sharrock" wrote in message
...

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
don wrote:

I currently have a Potterton 16/22 boiler driving the central heating
via a pumped circuit, and the hot water cylinder via convection.

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

From installation in 1973 my ground-floor wall-hung
Potterton 10-16 has been driving 28mm 'gravity'
pipes up to an indirect ho****er cylinder in the loft.
I'd guess the total height is 2 x 8'6" plus ceiling gaps
say ~20 feet? The pipes also have a number of kinks
as the heater is on an external wall and the tank is
about fifteen feet into the centre-line of the house.
As others have stated the cold water tank is mounted
on an over-engineered timber structure towards
the centre of the roof. Water is heavy.

It is about time you replaced all that and had it fully pumped. Gas has
just been hyped up.

Set Square wrote:

Does your loft have lots of headroom? Assuming that you're not going
for a
mains pressure hot water system, you'll need to get your cold header
tank
*above* the level of the hot cylinder. This will need supporting
*very*
well - water is heavy stuff!

The intention is to try and get everything mounted above a supporting
wall. The loft has enough head room for the cylinder plus a bit more. I
was planning to get the water line for the header tank a few inches
above the cylinder ... should I really be aiming to get the whole tank
above the cylinder?

If you're going fully pumped with a single pump, you'll need both HW
and CH
to share a common flow pipe until after the pump - where the circuits
then
split using zone valves (S-Plan) or a 3-port mid-position valve
(Y-Plan).
[See http://content.honeywell.com/uk/homes/systems.htm]

At the moment, the pump is directly above the boiler. My original plan
was to put a 3 port valve directly after the pump and run a new 22mm
pipe run straight upto the cylinder in the loft. This seems the
simplest approach as it involves the least modification to existing
pipe runs.

If you currently
have separate circuits (4 pipes into the boiler) this will need
changing.

Yes, it has 4 pipes. Is it a simple case of capping off the existing
pipe for the gravity cylinder? Or does it need to be a circuit with
water in to stop the boiler over heating?

If your boiler can stand it, you might consider converting to a
non-vented
(sealed) primary circuit - using a pressure vessel and filling loop,
and
getting rid of your small F&E tank.

Is the advantage here that you're losing the tank or is there an
additional benefit?

Thanks,

Don

Brian Sharrock wrote:
From installation in 1973 my ground-floor wall-hung
Potterton 10-16 has been driving 28mm 'gravity'
pipes up to an indirect ho****er cylinder in the loft.
I'd guess the total height is 2 x 8'6" plus ceiling gaps
say ~20 feet? The pipes also have a number of kinks
as the heater is on an external wall and the tank is
about fifteen feet into the centre-line of the house.
As others have stated the cold water tank is mounted
on an over-engineered timber structure towards
the centre of the roof. Water is heavy.

I'd be in a similar position as the cylinder needs to move towards the
center of the house (for headroom reasons).

The other reason for the conversion is that we suffer slow recovery
times (admittedly this could be down to the scale in the 30 year old
hot water cylinder), and when the hot water is on in the summer the
radiators become warm (I guess because of convection into the main
central heating loop).

Don

In an earlier contribution to this discussion,
don wrote:

Set Square wrote:

Does your loft have lots of headroom? Assuming that you're not going
for a mains pressure hot water system, you'll need to get your cold
header tank *above* the level of the hot cylinder. This will need
supporting *very* well - water is heavy stuff!

The intention is to try and get everything mounted above a supporting
wall. The loft has enough head room for the cylinder plus a bit more.
I was planning to get the water line for the header tank a few inches
above the cylinder ... should I really be aiming to get the whole tank
above the cylinder?

Yes! Consider the situation where you're running a bath and the header tank
is less than full, because the mains feed can't keep up with the rate of hot
flow. Once the level gets below that of the top of the cylinder, you'll be
relying on syphoning to get any further flow.

If you're going fully pumped with a single pump, you'll need both HW
and CH to share a common flow pipe until after the pump - where the
circuits then split using zone valves (S-Plan) or a 3-port
mid-position valve (Y-Plan). [See
http://content.honeywell.com/uk/homes/systems.htm]

At the moment, the pump is directly above the boiler. My original plan
was to put a 3 port valve directly after the pump and run a new 22mm
pipe run straight upto the cylinder in the loft. This seems the
simplest approach as it involves the least modification to existing
pipe runs.

If you currently
have separate circuits (4 pipes into the boiler) this will need
changing.

Yes, it has 4 pipes. Is it a simple case of capping off the existing
pipe for the gravity cylinder? Or does it need to be a circuit with
water in to stop the boiler over heating?

Disconnect it at the boiler itself, and blank off the "hole" in the boiler.

If your boiler can stand it, you might consider converting to a
non-vented (sealed) primary circuit - using a pressure vessel and
filling loop, and getting rid of your small F&E tank.

Is the advantage here that you're losing the tank or is there an
additional benefit?

If you *don't* do this, you will need to raise the F&E tank to a fair height
*above* the highest point in the primary circuit - which is now the coil in
your hot cylinder. With the limited headroom available, you're in danger of
having the primary circuit "pumping over". Also, you'll have to run a vent
pipe all the way from the boiler side of your zone valves to the new F&E
location. A sealed system would prevent pumping over, and would do away with
the need for a vent pipe. It's also much better at keeping air - and the
resultant corrosion - out. [The downside is that if you've any grotty old
radiator valves, they may start leaking with the increased pressure.] Maybe
a good time to replace all the valves with TRVs (on all rads bar one) and
drainable lockshields at the other end.
--
Cheers,
Set Square
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Set Square wrote:
Disconnect it at the boiler itself, and blank off the "hole" in the
boiler.

Looking at the boiler, I think this would mean removing it from the
wall as the pipes feed into the back of the boiler. This is something I
was hoping to avoid doing as I believe it would mean getting in the
professionals (as it would involve disconnecting the gas pipe
temporarily.

Don