Think the filling loop is letting water through

[Matt79n]

Hi, the pressure on my boiler was low, so, I opened the filling loop (little black tap on silver braided flexi pipe) topped the pressure up and turned it off. however the pressure didn’t stop rising. Now the overflow outside is just like a running tap. Now I can lower the pressure by turning the sink tap on and reducing the water pressure or by turning the stop tap off.
this makes me think the filling loop tap isn’t closing when I turn it off.
Can anyone help?

 

[foxhole]

Should be a black tap either end , both should be off. You may have snapped the black plastic meaning the metal valve has not moved , remove black section ( one small screw) and turn off using a set of pliers.

 

[Matt79n]

Thanks, I’ll give it a go

 

[Matt79n]

It’s just one tap though, the other end of the braided pipe goes into one of those silver barrel things that looks a bit like an isolation valve but with no turning bit for isolating.

 

[CBW]

Still might be what was said above, remove the screw and see if the middle spindle has actually turned. If it’s inline with the pipe then it’s not moved, if it’s across it then it’s letting by

 

[foxhole]

It’s just one tap though, the other end of the braided pipe goes into one of those silver barrel things that looks a bit like an isolation valve but with no turning bit for isolating.

Will be a one way valve, prevents radiator water running back into your cold supply .