Adding a Zone to exisiting CH system

[aelitaman]

Current system is combi boiler and for the central heating I have a 22mm core central heating ring (if this is the correct term). The rads are dropped of from the flow pipe and then returned to the return pipe. The boiler is in the coal shed the flow and return pipes enter the house are fed into the roof space above the basement. the basement rads and ground floor rads are connected to the 22mm pipes whist running through this roof/floor space. When the 22mm ring gets to the stairs then it is routed vertically upwards when it reaches the floor of the next level it branches out under the landing floor and the bedroom and bathroom rads are dropped of this part of the ring.

So I want to zone of the upper floor rads and the logical place to get access is to the 22mm flow and return pipes when they go upto the next floor at the stairs.

So advice required should I put a 2 way spring motorised valve on the 22mm flow pipe here and then put a towel rail in the cloakroom so there is always a flow and return open for the boiler.

Or should I put a three way valve here that when closed makes a connection between the 22mm flow and return at this point and when open allows flow upstairs.

Any advice much appreciated.

 

[D_Hailsham]

So I want to zone of the upper floor rads ... should I put a 2 way spring motorised valve on the 22mm flow pipe here and then put a towel rail in the cloakroom so there is always a flow and return open for the boiler.

Presumably, as you have a combi boiler, there is no zone valve on the heating circuit at present. Provided a zone valve to the upstairs rads still allows the downstairs rads to function, there should be no problem. But, with this arrangement, you cannot heat upstairs without heating downstairs at the same time.

As for needing a towel rail, this should not be necessary as you should have one rad which is open all the time, even if all others have thermostatic valves.

 

[aelitaman]

So I want to zone of the upper floor rads ... should I put a 2 way spring motorised valve on the 22mm flow pipe here and then put a towel rail in the cloakroom so there is always a flow and return open for the boiler.

Presumably, as you have a combi boiler, there is no zone valve on the heating circuit at present. Provided a zone valve to the upstairs rads still allows the downstairs rads to function, there should be no problem. But, with this arrangement, you cannot heat upstairs without heating downstairs at the same time.

As for needing a towel rail, this should not be necessary as you should have one rad which is open all the time, even if all others have thermostatic valves.

Thanks for the reply. Yes understand that it will not make a full independently controlled 2 zoned system, but at least it will allow me to not heat the upstairs when not required, which should save some money.

 

[DP]

Better to instal a three port midposition valve and have two zones independently controlled. Towel rail could be fitted before the valve so it heats when heat call is made to either zone.