vailant turbomax lukewarm rads

[benplumb]

hiya - i have a vailant 282 turbomax combi - its been fine for previous winters but since turning on the central heating i can only get hot radiators upstairs and lukewarm rads downstairs - ive bled them out and turned the control valves down a bit on the hot rads.
pump is on higher speed setting and boiler stat is on max
bg have serviced the boiler &are recomending a powerflush for £500 - not sure the system is blocked the house is less than10yr old - any suggestions greately appreciated - could the pump be faulty ?

 

[twgas]

Are you on a contract with BG, if so call them out.
Mind you they have cancelled 100s of jobs today because of the weather.

 

[benplumb]

no not on contract - anything i can try myself ? - change the pump ?
thanks

 

[screech]

these boilers have a built in bypass which can get muck in them or become weak so the water will go round the boiler rather than the system