I was bleeding the air out of hydronic heating zones and I notice some mineralization on bleed valve attached to my air scoop. I took the Schrader valve cap off and tapped the valve I noticed it was crusted stuck. When I tapped it it came free and quite a bit of air came out (which would explain why I had to bleed my zones).

Can I put a couple drops of CLR on the valve to try and clean it out and prevent the mineralization? We have a softener but still the water is hard. The valve was just replaced last year (was a few years old and had been neglected). I know they are cheap and easy to replace but just trying avoid it if I don't have to.

1 Answer 1


A property piped boiler system would include a dirt separator which helps to reduce the amount of dissolved solids in the system. Inhibitors can be used to improve water quality as well. Softened water is only going to help so much as a boiler system does not consume water, it circulates it. Sometimes controlling water quality is difficult and auto air vents have a shortened life due to build up on the needle valve seat. In those cases I use a ball valve like

this one pictured

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Home Depot

This allows you to either periodically allow the auto air vent to function as an auto air vent or as a more convenient manual vent. It also provides a simple method for isolation to replace it in the case of a failure. It will also facilitate cleaning the air vents with CLR, which is totally fine.

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