Andy Hall wrote:

That's a good reason. Presumably the boiler has a large thermal mass
and quite high non-modulated output and the previous cylinder was
unable to take what it could deliver.

Yup, that's what I concluded after spending a lot of time trying to
eliminate the short cycling. Put in the heatbank and presto, problem solved.


In this instance, a heatbank is ideal because it can swallow all the
output.

I do like the other advantages too. When the CH comes on, it takes no
time at all for the rads to heat up. Also we now have 'mains' pressure
HW to all the taps + showers, which means quicker bath fillups.


--
Grunff