On 25/10/2019 23:09, T i m wrote:
On Thu, 24 Oct 2019 19:19:26 +0100, Steve Walker
wrote:

On 24/10/2019 01:14, T i m wrote:
On Wed, 23 Oct 2019 22:10:17 +0100, Steve Walker
wrote:

snip

TRVs and single room stat only run the system while that one room is too
cold. Once it heats up, the whole system stops, even if other rooms are
too cold. The whole system only runs or stops at the same times of day.

Yup. ;-(

Timer/stat per room allows each room to have different times as well as
temperatures, runs while any room is too cold and shuts down boiler and
pump when there is no demand.

Yup. So, more complexity than TRV / no room stat arrangement and
energy wasted on the valves, if electric?

Hardly complex.

We will see.

Each timer/stat simply switches a valve.

So, extra timer/stats and special valves. How many parts in each
compared with a wax pellet type TRV?

Yes, extra timer/stats and valves. The timer/stats were £14 each at
Maplin at the time and the valves (normal Honeywell 2-port) were less
than £20 each during a clearance at B&Q.

All the valve
limit switches are connected together, so any open valve energises the
boiler.

Ah, all self powered and wireless then, or do you actually have to
have more complexity than a straight TRV?

The valves are bunched together at the manifold points, so junction box
to valve wiring 2' max. The wiring for the stats is just alarm cable,
easy to run along edges and so on, with no great disruption (that's why
I chose to use 12V).

The valves waste very little energy, they are rated at only 6W each and
are only energised when heat is required, so unlikely to be totally
wasted energy anyway - it's a tiny bit more heat ending up in the house.

Ok.

I had TRVs originally and making each room its own zone is far more
flexible.

By flexible I'm not sure how much more flexible you need other than to
have each room set at whatever temperature you like independently of
any other?

Well, the bathroom and living room are set to heat up earlier than the
rest of the house during the week, for me getting up and going to work
early. The bathroom is also heated for part of the evening, but not
during the day or the rest of the night and it shuts off well before the
rest of the rooms. The kids bedrooms are heated in the evenings, as they
spend time playing or programming there, but not in the day, except at
the weekends. The conservatory is heated in the evenings, as we eat
there and and at the weekends, as our middle son has his computer there.
Kids bedrooms and conservatory go off before the living room, because we
stay up a lot later than them. Our bedroom is heated during the day, as
my wife is ill and spends a lot of time lying down there, but dressed
and not actually in bed. When the system was originally put in, it was
used to keep the boxroom warm enough for our first son as a baby and
later to do the same with the front bedroom for both of our younger
children.

Basically allowing each room to be heated at a time when it is useful,
rather than all rooms being heated just for the sake of one.

eg. I set each room up for her about 5 years ago and she's not asked
me or changed them herself ever since?

I'm not saying that having ultimate control isn't a 'nice / good
idea', just that I question how many people would ever make full /
regular use of it or miss the 'flexibility' over straight TRV's?

And how much energy is used heating all the rooms, even those that
aren't going to be used really for most of the day, while trying to heat
a particular one or two that are?

SteveW