Heat only boiler set up

[dishman]

Moved into a new property and the set up consists of a modern heat only boiler circa 2010. There are header tanks for the hot water and central heating in the loft.

I assume with it being a modern heat only boiler that the system is fully pumped (both central heating and hot water).

However, as it is open vented, am I correct in that it is classed as a low pressure system?

The reason I ask is that the bath has a bog standard electric shower (I dislike these) and I would rather have a thermostatic mixer tap with shower attachment.

http://www.wickes.co.uk/Wickes-Aprillo-Thermostatic-Bath-Shower-Mixer-Tap/p/100402

If so, I assume (If I am correct on the above) I need one rated for low pressure systems.

Out of interest what, in this instance, determines how powerful the shower will be (in mixer tap config) if the system is not sealed and at mains pressure. I assume the cold water is still at mains pressure. Is the hot water pressure determined by the position of the header tank and gravity?

Apologies to the pros if I have got things totally incorrect. Please correct me at your leasure!

 

[bernardgreen]

Is the hot water pressure determined by the position of the header tank and gravity?

Basically yes, but there will be some loss of pressure along the pipe work when water is flowing to the shower so use a large diameter pipe for as much of the run as possible.

The mixer will give the best temperature control when the pressures of hot and cold supplies are the same. Hence feed the mixer with cold water from the tank in the loft instead of direct from the mains.

 

[dilalio]

If you want to improve your showering experience and keep the installation works to a minimum then take a look at the Aqua Lisa Quartz Digitial range of pumped showers with data cable for controlling the shower.

http://www.aqualisa.co.uk/showers/digital-showers