radiators not heating up

[pamw]

Have a Baxi combi boiler. As soon as cold spell arrived it decided not to heat all rads perfect timing. Some are bearly warm, some are red hot at the front and cold at back same upstairs and downstairs. Been suggested system needs flushing and will cost £500+. Since this visit the boiler now makes a 'boiling'sound and does not run for long. Think I am being ripped off, please help

 

[ollski]

The pump has been ruled out then?, that would be the first port of call.

 

[ChrisR]

Have you bled any air out of the rads?
If you close the best ones do the others improve?

 

[pamw]

The pump has been ruled out then?, that would be the first port of call.

One is being fitted tomorrow

 

[pamw]

Have you bled any air out of the rads?
If you close the best ones do the others improve?

Yes no air appears to be in them, will try closing best ones & see if any change