CH drain valves

[DIYspanner]

All done!

System has been run with cleaner, then drained and filled again with only water to dilute any remaining cleaner. Now drained off and filled with inhibitor.

The drain valve I mentioned above had too big a washer fitted so it wouldn't lift off its seat properly when I opened the valve. Now fitted with a slightly smaller washer and new o ring on the stem. No leaks.

Thanks All!

 

[Madrab]

The drain valve I mentioned above had too big a washer fitted

That's typical with an older valve, if the valve is tightened to much and the washer is over compressed, over time it swells and then stays like that and then gets caught. The one you replaced it with will be what it was to start with, if you see what I mean.

 

[DIYspanner]

How may years does inhibitor usually last?

 

[Madrab]

It doesn't have a shelf life really, it's a load of chemicals and minerals that won't 'evaporate' as such. It needs topped up if water is added to a system as it's strength becomes diluted.

Recommendation is that the strength is tested every couple of years, if the system is showing signs of increased corrosion or more added if the system needs topped up regularly until the leak is found

 

[DIYspanner]

Its occurred to me that I should perhaps have opened the drain taps on the boiler when draining the CH to get as much cleaner out of the system as possible since the pipes from the boiler run up/down from the ceiling. I did fill the system again with only water and ran it to flush out as much cleaner as I could and considering it was only 0.5l of cleaner, hopefully the small amount left in will not effect the inhibitor.

 

[Madrab]

Get a strip of litmus papers and test the PH of the system, if there is cleaner still in there it usually shows up as alkaline.

 

[opps]

Others here, that know more about plumbing than I do, have previously recommended smearing the rubber washer with silicone grease to reduce the risk of the washer sticking in the future.

 

[DIYspanner]

Others here, that know more about plumbing than I do, have previously recommended smearing the rubber washer with silicone grease to reduce the risk of the washer sticking in the future.

Indeed, silicone grease!
I put some on both the washer and o ring I fitted to the drain valve. On the two rad drain valves that were dripping, I took them out and fitted new o rings, coating them with silicone.