cold feed blockage

[kozak1968]

Can the techno heads can explain why the vent and cold feed on an open vent system gets blocked up. Thanks

 

[WHPES]

As system water is flowing past, debris settles out in the branch and sticks to the branch wall, gradually building up.

If the system has no inhibitor and / or the overflow is leaking meaning constant fresh water is coming in, more corrosion hence more debris.

Sometimes the design is such that it encourages debris to settle out in the link.