On Mon, 8 Aug 2005 10:22:17 +0100, "Ian Cowley"
wrote:
In message , Pete C burbled:
If it's a venturi shower with mains pressure cold and a gravity fed
hot try closing the stop cock a bit temporarily to see if reduced cold
flow will give a hotter shower.
We tried that a few weeks ago - the shower temperature doesn't change all
the way down to shutting off the cold water entirely - at which point the
hot water also stops. My understanding of the physics is that if you have
less cold water flow it'll 'suck' less hot water from the tank - the result
is that the mixing ratio is the same.
I see, fair enough.
By the way, we're in a first-floor flat. The hot water tank is in our flat,
so the head of water is really small - the shower head is at about the same
level as the top of the water tank. I think that's why the shower doesn't
get hotter with lessened cold water pressure - there's no flow of hot water
without the venturi effect.
The hot water pressure will be governed by the level in the cold water
tank the hot tank is fed from, which should be a bit higher up in the
attic.
Something else to check is to take the thermostat out, put it in a pan
of water, heat it up and see what temperature it opens. It's possible
the thermostat pocket has been bent towards the heating element or the
immersion heater orientated in such a way that the thermostat opens
prematurely.
Another potential problem is there may be strainers on the inlet to
the venturi shower that have been blocked with dislodged scale. If the
shower hose itself is quite narrow, or there is any scale blocking the
shower head that won't help either.
Something to try would be compare the hot flow just before the shower
mixer with a 1/2" hose siphoning from the same cold water tank that
feeds the hot tank, it should be at least as good.
If all else fails and the thermostat itself is faulty there are some
thermostats on this page that should do:
http://www.bes.ltd.uk/products/103.asp
However I'd set it to a sensible temperature using an decent
thermometer in a pan of water, rather than a dangerous temperature to
compensate for any problems. Otherwise there's a risk of people
getting injured later on for reasons you may not appreciate right now.
cheers,
Pete.