I currently have a simple sealed, pumped heating system with one zone,
a timer control for the boiler and TRVs on all the radiators. However,
the hot water cylinder is electric only via the immersion, and a long
way from the boiler.

I recently replaced the cylinder, and with foresight installed an
indirect one. I now have an opportunity to run a connection to heat the
HW from the boiler somehow - but routing the pipework is tricky!

The easiest solution appears to be to treat the HWC as just another
radiator, and tee it into the existing circuit just before the final
radiator (which is the closest one). Is this a possible/sensible
solution - how could I control the HW temperature? Or am I going to
have to bite the bullet and find some way of running a new zone all
the way back to the boiler?

Vaci

On 2 Jan 2007 07:28:42 -0800, "Vaci" wrote:

I currently have a simple sealed, pumped heating system with one zone,
a timer control for the boiler and TRVs on all the radiators. However,
the hot water cylinder is electric only via the immersion, and a long
way from the boiler.

I recently replaced the cylinder, and with foresight installed an
indirect one. I now have an opportunity to run a connection to heat the
HW from the boiler somehow - but routing the pipework is tricky!

The easiest solution appears to be to treat the HWC as just another
radiator, and tee it into the existing circuit just before the final
radiator (which is the closest one). Is this a possible/sensible
solution - how could I control the HW temperature? Or am I going to
have to bite the bullet and find some way of running a new zone all
the way back to the boiler?

Vaci

What are you going to do in the Summer when the heating isn't required ?

Andy

On Tue, 02 Jan 2007 07:28:42 -0800, Vaci wrote:

I currently have a simple sealed, pumped heating system with one zone,
a timer control for the boiler and TRVs on all the radiators. However,
the hot water cylinder is electric only via the immersion, and a long
way from the boiler.

I recently replaced the cylinder, and with foresight installed an
indirect one. I now have an opportunity to run a connection to heat the
HW from the boiler somehow - but routing the pipework is tricky!

The easiest solution appears to be to treat the HWC as just another
radiator, and tee it into the existing circuit just before the final
radiator (which is the closest one). Is this a possible/sensible
solution - how could I control the HW temperature? Or am I going to
have to bite the bullet and find some way of running a new zone all
the way back to the boiler?

Vaci

It would be contrary to Part L or the building regs to install a stored HW
system which did not have independent control of the time and temperature.



Without looking at the route for the flow and return pipes to the indirect
coil I can say how easy this is for you. Plastic pipe, used wisely and
correctly, will greatly simplify the running of pipes in suspended floors
and/or ducts.

You will need full S plan controls (see main FAQ).



If you did decide to go for the simple method [1] then you would use a TCV
(Thermostatic cylinder valve)[2] to control the temperature of the HW. You
will find that if you don't need to run the heating enough then you may
not get all the HW you require. However since you have a modern cylinder
then you should be OK, although some of the nearby radiators or more may
be robbed of heat while the cylinder is (re)heating. In summer and perhaps
at other times you will need to go back to the electric water heating.



[1] Which I absolutely have never suggested you do...
[2] Much like a TRV but with a remote sensing bulb that work on a cylinder
temperature range (50C-65C).
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

Ed Sirett wrote:
On Tue, 02 Jan 2007 07:28:42 -0800, Vaci wrote:

It would be contrary to Part L or the building regs to install a stored HW
system which did not have independent control of the time and temperature.

Yes, and would be annoying to operate, too. I think I'll just have to
do the Right Thing.

Without looking at the route for the flow and return pipes to the indirect
coil I can say how easy this is for you. Plastic pipe, used wisely and
correctly, will greatly simplify the running of pipes in suspended floors
and/or ducts.

If only I had any suspended floors or ducts! Alas my apartment block is
built like a car park - concrete everywhere! Plus the flat layout is
against me - the boiler in one corner, and the HWC in the far opposite
corner, separated by doorways and corridors. Even to get the pipework
from one side to the other will require going up into the suspended
ceiling - which will require some carefully placed air vents.

On Tue, 02 Jan 2007 15:37:16 +0000, Andy Cap
wrote:


What are you going to do in the Summer when the heating isn't required ?

Andy
TRV's could stop the rads heating.

On 2 Jan 2007 07:28:42 -0800, "Vaci" wrote:

I currently have a simple sealed, pumped heating system with one zone,
a timer control for the boiler and TRVs on all the radiators. However,
the hot water cylinder is electric only via the immersion, and a long
way from the boiler.

I recently replaced the cylinder, and with foresight installed an
indirect one. I now have an opportunity to run a connection to heat the
HW from the boiler somehow - but routing the pipework is tricky!

The easiest solution appears to be to treat the HWC as just another
radiator, and tee it into the existing circuit just before the final
radiator (which is the closest one). Is this a possible/sensible
solution - how could I control the HW temperature? Or am I going to
have to bite the bullet and find some way of running a new zone all
the way back to the boiler?

Vaci
Couldnt you have a 2 port valve controled by a cylinder thermostat and
a timer? Youd need a mains supply from the boiler and a 'demand' wire
back to the boiler. In any event you dont need to have the zone valves
next to the boiler if somewhere more central is more convinent.