"Richard Perkin" wrote in message
...

The name confused me when I was speccing the system, and I spoke
to the Keston Technical Department who confirmed that it was not
a Honeywell product. Unsurprisingly, they did not offer any more
info on where I could get a lower cost alternative but did
confirm that any OpenTherm (OT) device would do.

"Any" OpenTherm device will do,
that is the beauty of the OT
protocol, you may not have
realised that at the time.

Of course I realised it - that's one of
the reasons why I spoke to Keston. I
(like you) also realised that the asking
price for the 'Keston' controller was high
- but the company couldn't/wouldn't
suggest an alternative, and I struggled to
find one. Perhaps you know
of others readily available in the UK?
Or (for the rcord) where the
Honeywell OT device can be purchased?

Try Honeywel first. :-)

How is the DHW flowrate from the C36?

It's best described as 'adequate'. I was
hoping for better - indeed, a major reason
for selecting the C36 was its high output

14.5 litres/min is not starting.

However, despite this it is still
slower than I would like to fill a
bath with 'properly hot' water.
However, the flow rate for a drencher
shower is truly excellent, as you would expect.

The bolier is sited some distance from
the bathroom, and the length
of pipework has a significant impact
as there is a considerable
'slug' of cold water to come from the
tap before the hot water flows well.

But these are well known consequences
of using a combi, so I'm not surprised.

Dead leg pipe is well ...dead-leg pipe and will be the same whether from a
combi or a cylinder.

Appears the electronic controls are doing their job. Does it
maintain a constant room temperature?

No, it doesn't quite work like that. The Theben controller has two
modes of operation: you can set a target room temperature, or (if the
external temp sensor is present) use weather compensated control.

That is probably the function of the pcb. It appears it can't do weather
compensation "and" room temperature influence on the compensation.

Quite how the device implements the
control I'm unclear (which is
unlike me - I like to know the nitty gritty)

It "appears" it is either or. Weather compensation or room temperature
control depending what sensor is connected.