Have just installed the central heating header tank, in a little-
difficult-to-access loft, with a lever valve right next to the
ballcock as it should be.

I'm tempted to add a second lever valve in series with the first, in
the ground floor utility cupboard next to the hot water tank.

Should the header tank overflow ever start pouring (or any other part
of the system for that matter), it would make for a no-hassle shut-
off, until the ballcock/whatever can be replaced/repaired (as well as
making for easily controlled system filling).

However, there would always be the temptation for a future owner to
shut it off and forget about it.

So trading off convenience against a potential hazard - your thoughts?

The system actually uses a 250L thermal store, so vast amounts of
water would have to be lost before the tank/boiler (Rayburn 480K)
circuit could get air into it.

I'm also planning to have lever valves on the two tank-to-radiators
circuits to isolate them independently from the tank - but obviously
*not* on the boiler/tank circuit (apart from the valves either side of
the pumps).

Lowest point(s) in the system will be the 3 pumps (2 heating circuits,
1 boiler circuit - so it's "pump plan"), so this seems the obvious
place to add drain-off points. ISTR it's smart to raise the dop's
slightly wrt to the lowest point to prevent them sluding up. Same with
the pumps - have a *slightly* lower point for the sludge to collect?

I *think* there should be no need for air bleed valves, apart from
those in the rads - in normal use. But some extras might be useful for
system filling, and I can see that the dop's next to the pumps might
make for the easiest initial/partial system filling.

Comments/suggestions from those with similar systems or experience?

In article
,
wrote:
Comments/suggestions from those with similar systems or experience?

Just wondering why you're using a header tank in this day and age?

--
*Do infants enjoy infancy as much as adults enjoy adultery? *

Dave Plowman London SW
To e-mail, change noise into sound.

Just wondering why you're using a header tank in this day and age?

For a straightforward self-install. With a thermal store, there's no
real *disadvantage* to a vented system, unless it's a tankless combi
system chosen to save space in flats etc.

In article
,
wrote:
Just wondering why you're using a header tank in this day and age?

For a straightforward self-install. With a thermal store, there's no
real *disadvantage* to a vented system, unless it's a tankless combi
system chosen to save space in flats etc.

Ah. Don't think you mean a central heating header tank?

--
*Never underestimate the power of stupid people in large groups.

Dave Plowman London SW
To e-mail, change noise into sound.

Ah. Don't think you mean a central heating header tank?

Sorry, feed and expansion tank. Header tank is so entrenched in me I
can't shake the term.

wrote in message
...
Have just installed the central heating header tank, in a little-
difficult-to-access loft, with a lever valve right next to the
ballcock as it should be.

I'm tempted to add a second lever valve in series with the first, in
the ground floor utility cupboard next to the hot water tank.

Should the header tank overflow ever start pouring (or any other part
of the system for that matter), it would make for a no-hassle shut-
off, until the ballcock/whatever can be replaced/repaired (as well as
making for easily controlled system filling).

However, there would always be the temptation for a future owner to
shut it off and forget about it.

So trading off convenience against a potential hazard - your thoughts?

Do it.
There would be no hazard if it got turned of at some time. The worst that
would happen is that the F&E tank would dry up in a year or so and the
boiler would stop working.
This is a fairly common occurence when float valves get stuck in the closed
position and the boiler just cycles on its own stat when there is not enough
water to circulate round the system.

The system actually uses a 250L thermal store, so vast amounts of
water would have to be lost before the tank/boiler (Rayburn 480K)
circuit could get air into it.

I'm also planning to have lever valves on the two tank-to-radiators
circuits to isolate them independently from the tank - but obviously
*not* on the boiler/tank circuit (apart from the valves either side of
the pumps).

Lowest point(s) in the system will be the 3 pumps (2 heating circuits,
1 boiler circuit - so it's "pump plan"), so this seems the obvious
place to add drain-off points. ISTR it's smart to raise the dop's
slightly wrt to the lowest point to prevent them sluding up. Same with
the pumps - have a *slightly* lower point for the sludge to collect?

I *think* there should be no need for air bleed valves, apart from
those in the rads - in normal use. But some extras might be useful for
system filling, and I can see that the dop's next to the pumps might
make for the easiest initial/partial system filling.

Comments/suggestions from those with similar systems or experience?

In article
,
wrote:
Ah. Don't think you mean a central heating header tank?

Sorry, feed and expansion tank. Header tank is so entrenched in me I
can't shake the term.

Header tank's ok provided you say it's for the hot water. One for the
central heating primary can often get away with the cold feed turned off
for much of the time.

As regards your extra stopcock, I have one in the kitchen which cuts off
the feed after the kitchen cold tap. So I can shut down the feed to
everything after that while still having water for drinking, etc.

--
*Real women don't have hot flashes, they have power surges.

Dave Plowman London SW
To e-mail, change noise into sound.