On 05/11/2015 09:18, Dave Liquorice wrote:

Only quoting the OP and that's the maximum to avoid damage. What
ever, to me not having some regulation of the UFH loop temperature
independant of the store temp isn't right. Limiting the store to 60 C
reduces the amount of energy it can store by about 30%.

And a store with a 60 C max must struggle to provide a decent
quantity of DHW unless the OP has that mixer valve set to the
pathtically low "safe" 43 C. Ours is set at 53 C or there abouts, hot
as in you can put your hand in it but don't want to keep it there for
more than a few tens of seconds hot. The store middle temperature is
normally about 70 to 80 C, top can get to 90+ if I miss judge the
weather and get a good burn going in the stove without the heating
coming on enough. It can deliver a bath of DHW at 53 C and 15 to
20l/min before it starts to run out heat.


The regulation is done by the stat keeping tank at 60 ........ you may
deem that not enough but seems to work fine.
Stat is fitted in lower 1/3 of store.

There is never any shortage of ho****er ... this is set to 53 deg ...
and runs at full mains pressure ... on 22mm pipes.

You can run it full flow to fill a bath and still running hot when bath
is full.

Nu-Heat advise the high efficiency cross flow heat exchanger (rather
than a coil)allows this.

Flow is from mains pressure of 3.5bar at 25L/min .. and has never
once run out of ho****er when in use.