"Graeme" wrote:

Hello Graeme

G| If you have a pump, mounted on the floor of the airing
G| cupboard, and this is sucking from an Essex flange, if the

Mine's the same, except using a Surrey flange. No big difference
though.

G| cold water supply rate to the cylinder is less than the hot
G| water pump rate, won't this result in problems? Surely the
G| level of water in the cylinder will lower and air will be
G| drawn in through the vent, and that the domestic hw will
G| also be cut off when the vent empties?!
G| I can't see how this always isn't a problem, or does the
G| height of the coldstorage 'always' provide a higher flow
G| rate than a 1.4-1.8 bar pump?

I wouldn't worry.

The water level in the vent and the main supply tank will be the same,
so to empty the vent enough to suck air in it would need to drain the
tank pretty much. I suppose it's theoretically possible if the route
to the tank is convoluted or the valve there is half closed, but in
practice it doesn't seem to be an issue.

I'm not sure how much pressure rating affects things. I've got a 3-bar
pump, but I don't think that changes the flow rate much. That's more
down to speed of impellor rather than size of motor, I'd guess?

--
Simon Avery, Dartmoor, UK
uk.d-i-y FAQ: http://www.diyfaq.org.uk/