On Sun, 26 Jun 2011 21:06:59 +0100, Vortex10 wrote:

I installed an XCel (475 litre) 18 months ago and concur it's a doddle.

Inputs are Gas, Leccy and solar. Solar loop uses a Navitron SFB30-47.
30 tubes. I use a Resol Deltasol BS plus controller

For excess heat the top stat on the XCel turns on the pump at IIRC 85C.
For me this has NEVER happened.

Ah but you don't have the "uncontrolled" heat source that I intend,
the wood burner. If a store is sized correctly for the solar panels
it would have to be a very long and bright day for it to overheat the
tank. It might happen if you are away and there is no use of hot
water.

I've been fiddling with the DPS online designer thing and what it
comes up with ticks more "like" boxes than "dislike" ones. I'm still
not happy about the active DHW via the pumped plate heat exchanger.
One question that those with such things do you get any warming of
the DHW if the pump doesn't run? Thinking that there might be some
gravity flow in the primary of PHE.

Now to find an MCS registered installer who is willing to do what I
want not just what they want to sell. Rang a couple of companies
yesterday, still waiting for them to get back to me... Like some one
else mentioned, no one seems interested in new work, maybe they are
all just too busy?

--
Cheers
Dave.