I've a basic question:

I'm trying to drain the hot water in order to fit some new taps.

I've turned off the feed to the hot water cylinder (this comes in to the 
bottom of the cylinder from the storage tank in the attic - correct?).

How long should I need to wait for it to then drain - I thought the 
pressure 'drives' the water and with this valve shut it would be pretty 
instant.

All it does is run cold - pretty instantly - open the valve and it runs 
hot again! But the flow rate itself never changes. I've waited a couple 
of minutes. This doesn't make sense to me given my very limited 
understanding! What's going on? Do I just need to be more patient?

TIA,
Jason

"BigJason" <"jbarstow at z00m co uk"> wrote in message
news:422b37d4$0$549$ed2619ec@ptn-nntp-reader03.plus.net...

> I've a basic question:
>
> I'm trying to drain the hot water in order to fit some new taps.
>
> I've turned off the feed to the hot water cylinder (this comes in to the
> bottom of the cylinder from the storage tank in the attic - correct?).
>
> How long should I need to wait for it to then drain - I thought the
> pressure 'drives' the water and with this valve shut it would be pretty
> instant.
>
> All it does is run cold - pretty instantly - open the valve and it runs
> hot again! But the flow rate itself never changes. I've waited a couple
> of minutes. This doesn't make sense to me given my very limited
> understanding! What's going on? Do I just need to be more patient?
>
> TIA,
> Jason


Hot water turns to cold water?

The only thing I can think of is "do you have any mixer taps that may be
allowing a backflow to the hot water supply?". Try turning the valve between
the cold water storage tank and the cylinder off again with the mains water
stop tap turned off.

Adam