Worcester Bosch System boiler with vented or unvented hot water cylinder?

iandv

Hi

With a Worcester Bosch system boiler (its new just 4 years old and a Greenstar 30CDi ) what is the best set up to have it with an unvented hot water cylinder or a vented hot water cylinder (which is what we have at present) ?

Because we are having problems with the air getting into the shower supply from the pump I think because its draining the hot water cylinder quicker than the cold water storage tank in the loft can replace it with, and the volume of water in the storage tank is not enough to create enough header pressure in the cylinder which is causing the air in the pipes?

Does this sound feasable?

The the other reason why we are now looking at getting an unvented hot water cylinder is because it will get rid of the storage tank in the loft and we can also get rid of the old hot water cylinder in the airing cupboard in the bathroom freeing up space, as the unvented hot water cylinder could be re-sited downstairs in a room where the boiler currently is in the garage.

How much work is this likely to be and what would be rough costs in South Wales, I have also read the plumber needs to be G3 accredited to fit unvented cylinders.

Seronera

I'd need to know if proper shower flanges were installed on your current cylinder when the shower pump was installed, or at the very least where the take off point for the shower is. Many of these air problems are caused by poor installation and not modifying the cylinder hot water outlet to cope with the high level of demand a pump creates.

There is nothing wrong with an unvented, but you might be spending £1500 or more unnecessarily if there is no shower flange on your current cylinder which might cost £150 to install