Should you powerflush a microbore system

[Zig168]

The system is about 20 years old and has never been cleaned. The radiator water looks like tar and several radiators are warm at top and cold at the bottom.

What would be the best steps to clean the system?

I have spoken to several engineers. One only recommends a magnacleanse due to being a microbore system. The other engineer was willing to use a powerflush.

I'm concerned that the Powerflush could cause a blockage or cause the pipes to leak due to the age and amount of sludge in the system. Maybe I'm just being anxious ?

Thanks for reading.

 

[Last Plumber]

I would powerflush it with magnacleanse in series.
If it has solids in it that are capable of blocking it, they probably will eventually anyway and need removing. If they cause an issue during the flush, the person flushing should be capable of dealing with it.

 

[olegthepoleg]

Remove radiators prior to flushing and connect radiator valves with poly pipe, then use the valves to flush sections of pipework!