Mike Barnard wrote:
Hi all.

Any CH design guru's aid me in my small dilemma please?

I have a 1960's mid terrace Wimpy (spit) three bed house. It had no
CH at all untill a couple of years ago when I put a new combi boiler
in [1]. I also put a couple of rads in. It was not a complete system,
DHW was what I needed mostly. Now the time has finally come to finish
the job.

The dilemma is whether to zone off the rear two rooms upstairs. The
bathroom and bedroom 2 are north facing and in winter they can be much
colder than the rest of the house. The thremostat and timing controls
are in the open plan lounge; see description below. If the lounge is
nice and toasty, then the thermostat will not be telling the boiler to
fire up. Therefore the water in the pipes will not be heated and
under circulation. No matter how far the TRV's in these rooms open
they will recieve no heat.

Thoughts:

If I put a zone in to supply heat for these rooms its a lot more
pipework and electrics to try and hide.

If I'm doing these two rooms why not all of them.

If I do all of them am I going to lose heat when the upstairs is off
and downstairs is leaching up?

What else?

Layout is...

Front is facing south, rear north. 1 mile from the sea.

Front door opens directly to the living room.

Ground floor split into just two rooms:
- a living room to the front
- a dining room / kitchen to the rear

Open staircase from the living room to a landing.

Off the landing at the back is the bathroom and bedroom 2, (my 5yo
sons.)

Off the landing to the front is bedroom 1 (ours) and bedroom 3 (used
as a study.)

Radiator with no TRV in the lounge as the controls are here by the
stairs.
Radiators with TRV's in all other rooms.
Heated towel rail in bathroom.



Thanks for any eyeopeners.

Mike.



Mike. Its a contstant dilemma..

Ny feelings are as follows. First of all Radio stats are not THAT
expensive and save a lot of wiring, and TRV's are even cheaper.

What might be worth doing is adding - say - trv's to everything, and
plumb in a bypass loop, and then put a radio stat in the coldest room so
that at the least, the heating would stay on till that one was warm..you
could simply parallel the output of the existing stat and the radio stat.

That is the minimum of plumbing/wiring work: Ideally stats everywhere
feeding zone valves all wired back to the boiler is what you want, but
in practice its a hard way to retrofit stuff

The problem with the system I have described is when e.g. the radio stat
is set to a higher temp than the TRVs in that room..perhaps the answer
is to not have TRV's in that room at all..but then how to turn that room
down?

I don;t think there is a perfect answer..you will have to juggle the
complexities yourself




[1] Worcester Bosch Greenstar R35HE Plus. What a mouthful. As a
part of putting in a new kitchen, losing an airing cupboard and a wall
and associated HW tank and plumbing.