vokera 24 hw problem

[kazclan]

hi there
could anyone help me with boiler problem?
i have a vokera compact 24 combi boiler. when i turn hot water tap on, boiler kicks in for a few secs then goes out again. this continues for the period of time the tap is turned on. hence the water goes warm the cold but never gets a chance to get hot. when you turn tap off you can hear boiler filling up for a few secs afterwards. the heating does not seem to be affected. any help or advice would be very appreciated.
many thanks
mark(kazclan)

 

[weareleeds]

Change dhw thermister & while you're at it take out flow restrictor as it will soon reduce water flow

 

[kazclan]

Change dhw thermister & while you're at it take out flow restrictor as it will soon reduce water flow

thanks for getting back to me. looked thru manual. there are 3 thermistors shown. which one would be the one i would need to change?
took out restrictor soon after boiler was fitted after advice from this forum.
many thanks
mark(kazclan)

 

[weareleeds]

If i remember right on a compact it is on the hot water pipe outlet on rhs of heat ex under black grommet. Don't worry if old one is blue & new one is red