Flushing central heating radiators.

Hello. Could anyone tell me whether a plumber who recently flushed all of my central heating radiators when installing a new Worcester bosch greenstar cdi combi did the correct procedure.

1. He turned off the boiler ( to avoid over pressurisation).

2. He closed the Central Heating flow and CH return valves. Attached a hose to the drain tap on the combi and opened it.

3. Shut all TRV’s on every radiator.

4. Then opened the filling loop fully to get mains pressure.

5. Then opened each TRV individually and flushed the radiator dirt and magnetic particles down the sink.

6. Flushing the radiator until the water went clear. Closed the TRV and went on to the next one. Once the flushing was done did the reverse and closed the TRV then shut off the filling loop and drain tap. Opened up all the TRV’s and opened the CH flow/return. Switched the boiler on and then filled the Greenstar system filter with corrosion inhibitor.

The question is can someone confirm that this method of flushing above is correct and done in the right way. Is there anything i have missed.
Thank you for your help.

If he didn’t use a flushing pump then it’s not been done right. Bob

There are a variety of methods that can be used. The quickest and most effective is a flushing machine(but only a decent machine). Mains flush as your has been done is often nearly as effective especially if he reversed the flush. just a chemical flush is the slowest.

All of these should be done with the rads agitated with either a rad hammer or similiar.

There is british standard BS7593-2018. This is what has to be achieved and can be done with either any of the above.

Mains flush as carried out as described will remove non solid muck from base of the radiator, shocking the radiator will disturb the sediment and get it moving to be removed from the system. What the cold water will not do is remove what is above the base rib, for that slight spread is required to flush the radiator.

What has been done, I would accept as acceptable. Seen a lot worst. Get a good magnetic filter