Central heating and controls

[dancecaller]

Our central heating has been condemned because of a botched job on the flue (22 years ago and someone's just noticed!)

Should we have the thermostatic radiator valves replaced at the same time? Are some makes better than others? We are not happy with them because they sometimes stick, especially if we turn them right down, then they don't come on again.

[terence7556]

how many times has the system been serviced?
by the same person/firm?
are the rads, TRVs. pipework all 22years old
what size is the pipework? 10mm/15mm?

[gucciman]

can't go wrong with honeywell valves, but all valves sometimes stick especially when the system has been off all summer and is then turned back on as the weather gets colder