how to flush CH in bungalow (combo boiler in loft)?

[ishaqmir]

hi everyone

Fernox F3 has been circulating in the central heating system for a couple of weeks now, and as well as it clearing the blockage in my boiler/diverter valve I've noticed it has made the boiler operate very quietly, its as quiet as some brand new boilers i've observed, so really impressed.

I have the MagnaClean installed on the return pipe and cleaned it recently. So I do have a device to catch the sludge, however, reading posts on this forum I understand that the system should still be thoroughly flushed through right?

my question is I live in a bungalow so all radiators on one floor, and the combo boiler is in loft. only one radiator has a drain valve, its close to the bathroom.

now if i use that drain valve it won't even half empty the CH system right? because all the rads are on the same level?

i was thinking of just emptying as much as i can through that valve, then refilling and bleeding. and then let CH run for a few days again, then drain and refill again as before, let it run again for few days, and keep repeating, until eventually the water is very clear. then add inhibitor and forget about it.
will this method work ok? i don't want to try any messy method as had new carpets etc put in, so don't think the mrs would be happy if i got sludge splattered on walls and floor etc.

thanks

Ishaq

 

[roberta1000]

It depends.

If all of your radiators are fed individually by pipes from the loft, you're right, it won't. But if all of the radiators are fed from pipes at say, floor level or underfloor (as mine are) then the one drain valve will drain the lot apart from any piping below the level of the tap. You'll likely need to open the bleed valves on each radiator to let the air in.

 

[ishaqmir]

It depends.

If all of your radiators are fed individually by pipes from the loft, you're right, it won't. But if all of the radiators are fed from pipes at say, floor level or underfloor (as mine are) then the one drain valve will drain the lot apart from any piping below the level of the tap. You'll likely need to open the bleed valves on each radiator to let the air in.

Thanks for the reply.

The boiler has a 22mm supply and return pipe, which go down from loft and then split into lots of 10mm pipes which go underground in the solid concrete floor to all the rads, so no individual rads going straight to boiler. Does this mean I'll be able to drain most of the water out from that one drain valve?

Thanks

 

[roberta1000]

Yes (aside from the smallish amount of water in the piping below the level of the drain cock).