The central heating isn't working however I still have hot water. I can also hear the boiler working when the water is heated. The central heating started to switch on/off by itself and not it doesn't work at all. The boiler light doesn't come up either.
Is the problem with the boiler or with the switch?

Gordana, February 2005

It sounds like the diverter valve is not working i had the same problem

Grahame Deacon, December 2010

how do the heat exchange work

b. j., November 2006

This action would also work if the central heating thermostat is faulty, as it bypasses the thermostats on heating and water, using only the control on the boiler, which must be turned down to a minimum to prevent scalding from overheated water until the problem is identified and remedied.

Paul, May 2005

You should check motorised valves first.These give the same problem on my 10/16.
If the heating valve has stuck you would still get hot water!
Try putting the the valve in manual ie push the lever over and lock it.If this works you know it is the valve.
Touch them to see if one is colder.
You can replace the inner only-about £30 at spares stockist or B and Q.

Roger, March 2005