Valliant combi boiler problem

[mascia]

Can some one please help,

i have a valliant combi boiler and the hot water is not working properly, the heating is working fine but when i turn a hot water tap on the boiler lights for about 10 seconds then it turns off it lights again for another 10 seconds then turns off again, this repeats until you turn off the hot water tap, the water gets barely warm then goes cold then barely warm again then cold again. please can someone tell me whats wrong ? it seems like something is stuck.

thanks in advance

 

[Agile]

Its likely the diverter valve is stuck but as you dont bother to tell us which model thats only a first guess.

There is more to diagnosing boiler faults than guessing as most symptoms can have several possible causes.

Tony

 

[mascia]

Its likely the diverter valve is stuck but as you dont bother to tell us which model thats only a first guess.

There is more to diagnosing boiler faults than guessing as most symptoms can have several possible causes.

Tony

sorry mate ive been trying to find model on the boiler, its a
Valliant VCW GB 242 EH combi boiler, the problem as explained is that when you open a hot water tap the boiler lights for about 10 seconds then turns off, lights again then 10 sec later turns off again, the water gets barely warm then cold and so on, there is a dial in the middle of the boiler that i think is related to the water temp, it seems to be stuck and can only be turned with some grips could this be the problem.

thanks for your help mate