Overflow box

[DAVID.T2]

Hi

I have been using a Tunze overflow box for about a year with no problems , about a month ago air started building up in the u shaped pipe and stopping the flow .I now have to re prime it every day
I cannot find any leaks , do you have any ideas ?

Thanks

Dave

 

[rvitko]

The flow is probably too low now. Maybe your return pump is dirty or algae has obstructed the intakes. When mine does this, these are the causes.