I live in a small terraced house, and the central heating system consists of just six radiators (4 upstairs and 2 down). The pipes to the radiators are 10 mm plastic microbore with valves at each end of the radiators. The boiler itself is a Worcester Greenstar Combi installed by a small local firm in
2003; I'm not sure how old the radiator system is, but I would guess about 12 years - it was already in the house when I bought it in 2000 - the pipework looks a bit amateurish to me but otherwise its been OK up till now.My problem is that 3 of the six radiators have stopped heating properly - they only get warm to the touch even though the TRVs are fully open (they're not stuck by the way). It started last summer with the two downstairs and now recently one of the upstairs radiators has stopped working as well (this seemed to happen in a day or two). They're all slightly warmer at the top than the bottom as one might expect, but otherwise they don't seem to have any noticeable hot or cold spots.
I had someone from the firm who installed the boiler to look at it. He said that powerflushing would cost around £400 but didn't seem at all sure that it would actually work very well with microbore pipes. He suggested taking the offending radiators out off at a time and flushing them out with a hosepipe as a first step. But given that the latest radiator to fail stopped functioning quite quickly, it doesn't seem to indicate a slow build-up of sludge as he seemed to think.
Given that I'm not competent to do this or any plumbing work myself, I'm rather reluctant to get people out to fiddle around with half measures that may not solve the problem. What would the experts advise?