How can I fix the boiler?

Yeah it does sound like you flow through the tap is too high a little tip to check it is to not open the hot tap on the bath that far just so the pressure isnt that great if your water gets hot then you no what area your looking at. Another thisng could be that your bath or shower could be using a mixer tap and that the cold side of this is passing to you hot water. A good way to check this is by isolating the hot water underneath the boiler and open the hot tap if you get a trickle or any cold water come out the get your taps changed. Good luck

G man
April 2008

Ity sounds like to flow demand of the bath/shower may be too great for the boiler to keep up with.

Have a service tech. check your boiler for flow rate & temp to manufacturers instructions (if you want to do this yourself you will need a weir gauge and water thermometer

T
April 2008