Our boiler is one where the hot water and heating are seperate, the hot water is set on a timer to come on twice a day but does not seem to heat up, the timer doesn't keep in time and only wants to work on pm. When we use the boost button to heat it up it cancels the timer back to 12.00 pm and switches off, we then have to press boost again for it to heat the water. The only way to get hot water is to press the boost button which takes over an hour to get hot water.
Try manually moving the lever on the three way valve(usually located near pump in cylinder cupboard)
Feel for heat on flow pipe into valve and with system calling for htg and hot water both pipes should heat up, one to coil in cylinder for hot water and other to heating circuit. The lever opens and closes the valve and you can lock in in the open position as a temp fix until you get a new valve or motor fitted. Obviously it could be many things but give it a go.
Dick Bindon
December 2008
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