can anyone please help, i have a potterton puma 80 its about 10 years old.the heating does not come on it just heats the taps up in the bathroom and kitchen and one rad only.the hot water works fine, if you just use the hot water when the tap is turned on i get hot water after about 30 seconds, but if i turn the heating on after a while the taps are very hot and the hot water is instant, its as if the heating is heating the hot water pipes to the taps instead of going to the rads,thank you