Flushing The System ?

[Chas123]

I need to flush my central heating system.

Can I just open the drain valves and let the water flow or do I need to stop the water supply to the cold fill tank, drain the system then refill and repeat?

When bleeding the radiators or cleaning the magnetic trap the water really is like ink. I'd like to let it flow untill it runs clear rather than drain and refill several times.

It's a vented system with a mixture of standard size pipes for distribution . . . but it has micro bore piping to the radiators. It has a history of rust blockages. When we first moved in the system completely blocked which cost a small fortune to rip up floorboards and replace a T joint where the rust had collected.

We had the magnetic trap fitted, I removed each radiator to flush indiviually and every year for the past 5 it has been chemically flushed and fresh inhibitor added.

There must still be a LOT choking up the pipeworks.

My thanks in advance.

 

[jtsplumbing]

Drain System then re fill adding Fernox F5 heavy duty cleaner run system as normal for 7/10 days flush again add Fernox F1 inhibitor using cheep make cleaners/inhibitors just as well not put any in, don't just go into loft and poor into tank, you need to make sure that chemical gets into system, if your doing this every year then you may have some other problem with system

 

[R.Oak]

Sounds like there is another issue with the system if this is a yearly occurrence. Could be corrosion inside a radiator(s) or the boiler.

 

[jtsplumbing]

My Thoughts as well, but we don't know how he has been using chemicals, as I told him its no good just poring it into header tank, maybe he will follow advise and do it properly , if he follows the guide lines, uses good quality chemicals it may solve is problem, if its still the same next year then he need to start looking at other likely faults.