still problem with gravity feed system

the gravity feed system consist 2 header tanks one for the central heating one for the hot water . with 1 pump. 3 way diverter for hot water and central heating or just hot water. hot water copper cylinder. 7 rads
the system has been standing for 6 monthes. on restarting many problems
due to system sludge.now been flushed out.
i had to replace the pump of which is compatable to this system due to scale build up reducing hole size either side of pump inlet and out let. a gate valve to copper cylinder had to be replaced due to gate broken
now i have " flushed the system completely so far as only clean clear water came out.
all rads but 1 get hot, the biggest in the living room flow pipe is hot but the return is cold and rad is cold, have replaced with new valves flushed rad. high pressure hose to return and clean water from flow. to illiminated any blockage. thinking on the lines of a power flush, BUT i think cause of flow problems is lime scale. also theres seem to be no hot water. any ideas please,

Yours is a fully pumped system.As you had blockages either side of the pump I suspect other blockages in pipework near the pump.Even though you have flushed the system this will not remove blockages that have become solidified inside pipe and around tees and elbows.Use a magnet to see if it is attracted to copper and if so,there is your problem.

so if there is magnetic residue in the pipework what is recomended to clear or clean the system

Also what i would like to know has anyone got a second hand power flush unite they want to sell. has i have had offers of work with a corgi reg plumber. new ones are from around £500

petewg said:

so if there is magnetic residue in the pipework what is recomended to clear or clean the system

Click to expand...

Then it's time to get out the pipe cutters