Slightly fizzy water coming out of radiator

[Giles Mann]

Drained down system a couple of weeks ago after having some cleaner in there for a couple of weeks - drained down system, re-filled, drained and topped up with Sentinel X100 added.

Unless I was mistaken, I thought that the pressure had maybe gone up 0.05 bar over the next couple of weeks. Decided to bleed a bit of water and will monitor pressure. Something I noticed though - the water was clear and with a slight yellowish tinge (which I think is ok?) but it also had a very slight fizz to it - almost like a flat fizzy drink. No air came out of the radiator prior to the water starting to come out.

Any ideas on what would cause this. Do I need to drain and re-fill again?

 

[BoilerBob]

If I was you I’d put a neutraliser into the system for a week then drain a put in the inhibitor. Bob

 

[Giles Mann]

Thanks Bob. Hadn't even heard of neutraliser and after reading what they do, I feel like I should have done this the first time round.

I think my issue is that the drain cock comes off the side of one of the radiators so even though I've tried to dilute the water that is in the pipes lower than this point, there will always be some residual.

I'm guessing it would be harmful to the system to leave it as it is?

 

[Madrab]

If the cleaner isn't flushed or neutralised properly then it can leave the system off neutral heading towards alkaline. If you have an alloy HEX especially then it can create hydrogen which can dissolve in the system water or appear as gas in the highest rad.

Best test I've found is to use a bit of Litmus (PH) paper, you're looking for a neutral PH balance of 7ish.

 

[durhamplumber]

Any ideas on what would cause this. Do I need to drain and re-fill again?

Bottle it and call it Coca Cola.