What seems to have happened is that the boiler HX got blocked up with crud that was released by the power-flush chemical but not actually flushed out of the system (the CH equivalent of DVT followed by pulmonary thrombosis - hey - that's a really great analogy, if I say so myself).
It also illustrates that chemicals and water flow will often not get the sludge mobilised - it just sits there in a heap in the bottom of the rad where the flow is slow to non-existent. Physically vibrating the rad is known to help. There's a tool for the job - see http://www.magnaclean.co.uk/ and ask Chris Adey about 'vibraclean'
It also illustrates that chemicals and water flow will often not get the sludge mobilised - it just sits there in a heap in the bottom of the rad where the flow is slow to non-existent. Physically vibrating the rad is known to help. There's a tool for the job - see http://www.magnaclean.co.uk/ and ask Chris Adey about 'vibraclean'