"Kevin" wrote in message
om...

I have noticed a damp patch on the wall in the hallway downstairs, it
has been getting gradually larger over the last few days. I suspect
it is coming from the hot water cylinder which is located directly
above this wall. I have had a quick look and cannot see that it is
leaking from any of the nearby pipes so I suspect the leak may be from
the tank itself. Is replacing the cylinder something that can be
DIY'd without too much trouble ? Any advice or pointers which might
help ? It is an indirect system with the cold water tank directly
above in the loft.

While I may be forced into replacing the hot water cylinder, it gives
me the opportunity to bring forward one of those jobs which I have
been considering. That is to move the cylinder up into the loft. I
realise I will have to replace the HW cylinder and CW tank with a
combination unit but are there any drawback to this that I need to
consider ?

The cold water section of the combination cylinder may not be big enough to
supply both hot and cold water, depending on which model you buy. The cold
section is designed to feed only the hot water in kost models. You can get
50-50 splits in combination units of 115 litres each. Then the cold water
supplying the bath can be taken off the tank also. You may have to cut out a
hole in the bottom of the cold water section and fit a tank connector for
the cold feed to the bath and basins. It is best to have a 22mm cold water
mains feed to the combination and fit a Torbeck ballcock which is either
open or closed, especially if you have an 80 litre cold section. The
Torbeck is silent fill. These are 1/2" connection, so it may be better to
fit two of them to get the fast fillup. If an 80 litre cold tank section,
then it acts as a break tank leaving the combination unit on low and safe
atmospheric pressure, unlike an unvented cylinder.

The problems is having high pressure showers. This can be achieved by having
a combi do only the shower. The CH side can be as a normal boiler. or, a
power shower pump, or a venturi shower.

Get a quick recovery coil in the combination cylinder/tank.

If the mains are good flow and pressure, a minimum 22-25 litres/min, then
consider a mains fed Pandora Heat bank. This can go in the loft and needs no
header tanks or overflow. All the house will then be at mains pressure. Easy
to DIY. Unvented cylinders require a BBA approved installer, heat banks do
not.

Go for it and best of luck.