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- 17 Feb 2006
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I'd like to flush my CH system doing something like this:
//www.diynot.com/forums/viewtopic.php?t=38902
Whenever I've need to add water to the CH I've always used the 'filling loop' pictured here:
View media item 5816
I say 'filling loop' because looking at the installation manual I see no mention of it, and the soldered joints hint that the installers added it. It joins mains and CH return. So looking at the manual and at the underside of the boiler I see another one which I've never notice before, joining mains and CH flow:
View media item 5817
Why would the fitters add the other one?
Does it matter which one I use? Even though the one going into the CH return is presumably acting against any one way TRVs I've never had a problem (perhaps they're all 2 way). Fill up, run for a bit. Let out any air. Add a bit more water, has always worked.
Why would the fitter add another one?
Anyway, main point of post - I want to flush. So after draining, closing all but one TRVS etc I let water in via the low filling loop (i.e. water into CH return) and out via a hose connected to drain off (at bottom of CH Flow):
View media item 5819
that's cleaning it one way, yes?
Then to reverse the flow use other filling loop, disconnect the lower filling loop from the CH return and that gives me an outlet (with suitable hose).
I know I may not get great flow, but that should work, maybe?
Only thing I don't know is which valves to close to stop water 'short circuiting' through the boiler - any advice there.
TIA, Mike
//www.diynot.com/forums/viewtopic.php?t=38902
Whenever I've need to add water to the CH I've always used the 'filling loop' pictured here:
View media item 5816
I say 'filling loop' because looking at the installation manual I see no mention of it, and the soldered joints hint that the installers added it. It joins mains and CH return. So looking at the manual and at the underside of the boiler I see another one which I've never notice before, joining mains and CH flow:
View media item 5817
Why would the fitters add the other one?
Does it matter which one I use? Even though the one going into the CH return is presumably acting against any one way TRVs I've never had a problem (perhaps they're all 2 way). Fill up, run for a bit. Let out any air. Add a bit more water, has always worked.
Why would the fitter add another one?
Anyway, main point of post - I want to flush. So after draining, closing all but one TRVS etc I let water in via the low filling loop (i.e. water into CH return) and out via a hose connected to drain off (at bottom of CH Flow):
View media item 5819
that's cleaning it one way, yes?
Then to reverse the flow use other filling loop, disconnect the lower filling loop from the CH return and that gives me an outlet (with suitable hose).
I know I may not get great flow, but that should work, maybe?
Only thing I don't know is which valves to close to stop water 'short circuiting' through the boiler - any advice there.
TIA, Mike