Andy Hall wrote:

On Sat, 16 Jul 2005 22:13:45 +0000 (UTC), "Hzatph"
wrote:


I have two questions that I am sure you can help me with.

1. I have been told that it is a requirement to have a room thermostat on
the heating system even if every radiator has a thermostatic valve. Is this
the case? It would seem to be a nonsense.


There should be a lock-out for the boiler. The normal way is not to
have a TRV in one room and to put a room thermostat in there. The
boiler will then be turned off completely.


2. Because of the proposed ground floor location of our new hot water
cylinder our Aga will not be able to heat it on a gravity thermosiphon. One
installer said a simple slow pumped system would work (with expansion tank
etc of course) - another said it would not. Any views?



I have a natural gas Aga, although don't use it for hot water.

With a gravity arrangement, the heat transfer is relatively slow.
You don't say which fuel type that you have on the Aga, but the NG one
has a maximum input of around 5kW. My concern would be that pumping
the circuit would result in greater heat transfer rate than gravity
and that the heat in the cooker store would then be depleted.

You could call Aga-Rayburn's technical support in Telford. I have
found them pretty good.

The Aga is a great cooker, but if you have an alternative means other
than electricity to heat the water, then that would be better. You
could then go for a fast recovery cylinder which could take
substantially more heat transfer.



I agree totally. The aga itself is a 24x7 room heater with a crude, but
effectoive cokker bolted into it.

It is NOT a water heater by any stretch of te imagination: Use oil boiler.

The only justification for using it for water heating is if you have an
electricfity supply problem and like hot baths by candlelight...