System flushing

[patagonia]

The installation instructions for our Kingfisher Mf Cfl 100kbtu boiler, which is located in the cellar, say there should be a drain point at the lowest point of the system but I can't see one there, though there is one in the hall on the ground floor. Will this present any problems when draining down/flushing the boiler? How does one drain the boiler itself? How does one know if there is an anti-gravity or check valve in the heating flow pipe?

Is power more or less risky vis-a-vis leaks than a mains pressure manual flush, especially on an old system?

Advice/information appreciated.

 

[gas4you]

Have you taken the front case off the boiler? Often a drain cock is wound into one of the lower spare tappings.

 

[EliteHeat]

Is power more or less risky vis-a-vis leaks than a mains pressure manual flush, especially on an old system?

In terms of pressure, powerflush is probably less risky as its low pressure, high velocity.

 

[chrishutt]

In terms of pressure, powerflush is probably less risky as its low pressure, high velocity.

True, but if the pressure is lower then the velocity would be lower too, wouldn't it?

The velocity of the water will be determined by the pressure differential between the ends of the loop in question which will be potentially much higher with mains flushing. I've carried out mains flushing on many older systems, typically with pressures of around 2 bar, and never had anything catastrophic happen.

However a rad once main a horrific noise as it suddenly reacted to the high pressure, although there was no noticeable distortion, and uni-directional TRVs can hammer like mad if high pressures are applied the wrong way.

 

[patagonia]

Thanks for replies. I meant to say when draining down/flushing the system, rather than the boiler. I haven't yet tried taking the cover off the boiler. I was concerned about how one would satisfactorily drain and flush the system if the drain cock is in the hall rather than the cellar. If the boiler is kettling, which it is, I understand one would have to put something in the system before flushing and run it for some days. Right? A local plumber I spoke to said there was no guarantee that either this process or power flushing wd cure the problem which is rather depressing. I find the noise very irritating.

 

[Timmyturtle]

A powerflush works by using a centrifugal pump to create high flow,any excess pressure is put into the machine by nature of the pump design

 

[Timmyturtle]

No i dont understand what im trying to say