Just turn it on to try it, what you are testing is that the HW zone valve is actually closing when the controls ask it to, it is common for them to fail
Very hot water at taps
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Just turn it on to try it, what you are testing is that the HW zone valve is actually closing when the controls ask it to, it is common for them to fail
Thermostatic mixers are a safety item, they mix a hot and cold water supply, to the exact temperature you preset on the dial of the mixer, so water coming out of the tap is skin safe. Your cylinder stat needs to be set at 60C, to prevent legionella. 60C out of the tap is quite hot to the skin.
My downstairs toilet is near the back door, with a wash basin which is very handy for quick hand washing after working in the garage or garden, which many tend to do under running water - it was also often used by kids. Problem was, the hot was just too hot for that, so I replaced both taps with one single tap, fed from a thermostatic mixer. Turn on the one tap and water quickly appears at a safe around 48C.
Getting back to your cylinder thermostat - you can easily tell whether the cylinder is up to temperature (or the thermostat working) by turning it and noting at what setting the thermostat clicks.
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How does this work? I’m intrigued.
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Ok, so assuming I did it correctly, I turned on ch, turned down the cylinder thermostat, and no heat seems to be passing into heating pipes. The hot water valve also sounded like it closed? Heard like a scalextric sound.
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Thanks for the detailed explanation, it sounds like I might need a mixer type to the downstairs toilet taps. Anyway the thermostat on cylinder clicks at about 58 degrees?
Heat rises and the element or heating coil does not go all the way to the bottom of the tank, so bottom third of it will and should remain progressively cooler the lower down you go. The lower down you place the 'stat, the less representative it is of the temperature at the top, so it will struggle to raise the temperature. Ideal position is between 1/3 and 1/2 up from the bottom.
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Ah, I actually meant I lowered the temperature, not the position. The position has remained constant at approx 1/3 from cylinder.
As already suggested, lowering the temperature, risks Legionella developing in the hot water system. My heating system has a facility built in, which once per week can bring the temperature of the tank up to 60C, to avoid the risk, if you normally run the tank at a lower temperature. I don't, I run my tank constantly at 60C.
Set cylinder thermostat to 60, measure temperature at the tap. If it’s 55-60 then everything is probably working ok, and maybe fit a TMV to downstairs toilet basin. If it’s 60+ then there’s either a slight overshoot on the cylinder thermostat or the zone valve microswitch could be sticking. Ian and Stem give great advice so heed well.
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