Unvented hotwater tank

david29dpo

A quick question please. To get rid of the header tank and copper hot water tank and not wanting to go down the combo boiler route, I would like to install a unvented hot water tank.
However, at the moment there is nothing wrong with my vented regular boiler so my question is....... As the new tank will be pressurised and the boiler is not, (i.e. the coil in the tank will still be gravity pressure) is the coil in these unvented tanks capable of withstanding the pressure difference?

karl-123

yes
your tank fed boiler, with its feed and expansion 5 gallon tank,
will now pump through, the unvented hot water cylinders coil,
the outside of the coil " the hot water " is under mains pressure,the coil can take the pressure,
its made of 22mm copper tube made into a loop,table x is what we use normally,table y is the soft stuff used inside inset fires,
its half hard " in between the two "

gas4you

Most good quality unvented cylinders will have the indirect coil made out of stainless steel and be a larger diameter than 22mm.