No hot water from mixer shower.

Hello all,

We have recently moved house and in the new house we have a mixer shower over the bath. It does not have a name that I can see, but is a chrome bar with temperature control at one end and turn on/off at the other end. It has a gravity hot water and a mains cold water supply. If I turn it on with the temperature at 38 nothing happens, if I turn the temperature down, at about 15 cold water flows. So I am not getting hot water supply.

If I disconnect the mixer from the water supply I can see that both hot and cold inlets are protected by nylon none-return valves held in by cir-clips. I think the reason for me not getting hot water is that the hot water pressure is not enough to open the non-return valve. The shower looks very new, no sign of any gunge or scale, and I wonder if it has ever been used.

My question is therefore would I be in order to remove the none-return valve from the hot supply. I obviously have the worry that if I remove the cir-clip all the insides will spew out in an unreturnable mass of springs and bits. Or, of course, should I do anything else.

Thanks for any help.

On Mon, 11 Feb 2008 01:52:28 -0800 (PST) someone who may be Chris Potts wrote this:-

That is the problem. The mixer should be fed by water supplies which are at the same pressure.

If it is a no-name mixer then it is probably one someone bought cheaply at somewhere like Lidl. If so then it is almost certainly designed for high pressure supplies only.

What to do depends on the head available at the shower, which you don't state. If the head is large enough then I would replace the mixer with one designed for low pressures and fed with cold water from the storage tank.

If the head is not large enough then I would probably fit a shower pump, also fed with cold water from the storage tank, though there are other options.

In both cases the cold water supply pipe must be taken from lower down the tank than the one which feeds the hot water system.

In both cases I would fit a thermostatic mixer.

I would also look at the hot water pipework to see if it is designed properly, as the person who connected a mixer obviously knows little or nothing about plumbing and is likely to have made other mistakes.