Silly question about boilers/CH

[simongii]

Hi,

Sorry if this is a really dumb question. I'm used to seeing combi boilers now with the sealed CH circuit and a separate pipe for HW on demand.

In a house I'm renovating the coil in the HWC seems to be fed from the central heating circuit (gravity fed). I suppose my question is is this normal? I'd assumed the boiler had a separate loop for HWC so you're not limited to having HW only when the CH is on and relying on the immersion for the rest of the time (and potentially all through the summer).

 

[JohnD]

it is more normal, on a gravity circuit, to have separate pipes for the cylinder all the way from the boiler, usually 28mm. Otherwise you get unwanted gravity feed round the radiators in summer. The pump will obstruct flow to the rasds a bit, but not completely. The pipes need to be well insulated.

Is there a cylinder stat; are there any motorised valves, what colour is the cylinder? It would be preferable to improve your setup. Post some photos.

You might possibly have a Cyltrol or a Tapstat thermostatic valve on the return outlet of the cylinder. Have a look.