On Fri, 29 Jun 2007 12:17:55 +0100, "Roger Mills"
wrote:

2. Can you reccomend a RELIABLE valve to use for just two zones?

Is there also a HW zone (although ISTR that it's a combi boiler, in which

No, its a combi and I have no HW tank. Saved me the space the
cupboard was taking.

case there won't be)? In any case, go for an S-Plan solution, with a
separate 2-port valve for each zone rather than trying to do it with a
single 3-port valve. Any of the well-known makes (Honeywell, Danfoss,

OK, googleing for S plan now sir!

Drayton, etc.) should be ok. Make sure you get ones with secondary contacts
which close when the valve opens - which you will need for switching the
boiler on whenever either or boths zones call for heat.

OK.

3. What about 'primary' rooms and rads without TRV's? As I understand
it, the rad in the primary room (the room with the controls in, yes?
Thats the open plan lounge in my house) should have no TRV. Do I need
a primary room in each zone? What if the controls are in the upstairs
hall which has no rad?

You need a room thermostat (preferably programmable if you want to heat the
2 zones at different times) in each zone. Each thermostat controls its
respective zone valve which, in turn, controls the boiler and pump. The
radiator which heats the space whose temperature is sensed by each
thermostat should *not* have a TRV - but should be fitted with two
lockshield valves so that it can never be turned off. If a zone's thermostat
is not very near to a radiator, it must at least be somewhere where the
temperature is *influenced* by that zone - otherwise the control system
won't work.

So, yes, I need a primary room in each zone. Thanks.

4. Websites? General CH design as well as zoneing.

You could do a lot worse than starting with the heating section of the DIY
FAQ at http://www.diyfaq.org.uk/plumbing/he...ngsystems.html

Have been there, but little to be found about zoning.

Thanks for taking the time, I really apprecieate it.

Mike.