It's proberly on full and the knob has been put back on incorrectly. If it travels anticlock wise about 360 degrees then thats it. The reason the hot water is not getting hot would then be down to a problem with the boiler. You are not even allow to take the case of these boilers unless you are a gas safe registared engineer as you are breaking a room seal boilers seal. Get a gas safe registared engineer out to see it.
Anygasman
December 2009
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