Thought I would pass on a piece of information that is relevant to the use
of Thermal stores and modulating condensing boilers, which may be of use to
others.

In 'normal' systems without a thermal store, modulating boilers would be
ideal, although they would be required to fire up regularly due to the fact
that there is no energy buffer present

With modulating system boilers which modulate the flow rate to maintain an
ideal "Delta T", when used with thermal stores a problem arises with the
production of domestic ho****er, in that the modulating reduces the heat
coming into the store when you need it under heavy loads.

The stored boiler water should really flow at a constant flow through the
heat exchanger in order that domestic hot water production be maintained
under heavy load situations.

With thermal stores it's better to go for a condensing, non modulating
boiler.

I have a Baxi Barcelona, and this by default is a 70,000 btu/h boiler, to
convert to maximum output of 80,000 btu/h you need to remove bridge No.2 on
the control pcb.

To turn off the modulation and have maximum output remove all 3 bridges on
the pcb.

The same applies to the 100HE

Rick