"Dave Gibson" wrote in message
...

"Peter Hemmings" wrote in message
...
Hi,

I have just had trouble justifying the buying of the above to my
neighbour and wondered if, with new boilers they can still be
justified.
Background: I have a Baxi Barcelona fully pumped with two zone valves
(DHW and Htg) with a CM67 in the hall and TRV's on most radiators but
not in the hall. I leave the Heating controller on 24 hours with the
DHW on once a day. I am very happy with the convenience of the
thermostat and its operation in keeping the hall and downstairs at
constant temperatures.

My next door neighbour has had a large extension built with 3 extra
rooms and has ditched his old oil boiler and is fitting a new Valiant
Combi non-condensing boiler. I told him of the benefits and he said
that he was told by the Corgi installer that, as the has TRV's fitted
(maybe to all radiators) and the boiler sensed temperature and was self
regulating (sorry forgot the correct terminology) it would be of no
benefit to him except the convenience of temporary overriding settings
when on holiday etc!!

Unfortunately my argument that it was more efficient in maintaining
temperature went on "deaf ears" as he insisted that TRV's would do the
same on each radiator! Unfortunately I could not think of a reasoned
case for my system and I am now not sure that there is one.

So, (at long last) can someone let me know if they are still
worthwhile in these days of self-regulating high efficiency boilers or
are the now redundant?

Thanks
--
Peter H

I have TRV's on all my rads and must confess that the only thing I use my
electronic timer/thermostat for is for the timer function (except at the
beginning and end of the heating season). Normally I set the temperature
to
26 deg and let the TRV's sort all the room temps out. Even though this way
round the circulation pump is on throughout my chosen heating periods I
still find it gives a higher overall efficiency.
I will add that the 'stat is in the hall, normally our coldest room. At
the
beginning/end of the heating season (like around now, April/May time and
Sept/Oct) I turn the hall rads off and reset the target temp to a around
22
deg. That way if we get a warm day the circulation pump stays off.

So in answer to your question, yes they still can be justified (IMHO).

In your case it acts as a high limit and an optimiser, if it has one.
having the pump continuously on is better than switching it off and on. If
a the last closed TRV opens heat is readily available and no warm up period
fro the boier. Make for a more even temperature.

If only TRVs are used on all rads then an auto by-pass valve needs to be
fitted.