Ever since installation about 5 years ago, the hot water delivered to the taps has been scalding. The hot water dial is set at minimum. The water flow rate is very good to the boiler (i.e., no problem with water flow rate in our area). Is there any other way to reduce the water temperature? Or is the boiler supposed to deliver such hot water? Thanks.

Roger Nunns, July 2009

Had this problem today, if you can feel the heating flow pipe getting hot when the HW demand light comes on (tap running) , then the primary side of the hw heat exchanger is blocked and water escaping back up the flow, it will not be the diverter valve.

karlos, July 2009

Sorry, not an answer but My W H 400 does exactly the same, usually.

steve morris, July 2009

The hot water thermostat may faulty, the maximum temp should be 60 deg C. If you have ever had the divertr valve changed then it may be on backwards. This means that it will be the c/h dial that would be controlling your water temp, so try turning that down and see if that makes a difference.

Ian, July 2009