UFH Manifold Leak

[hebridean]

I was wakened in the early hours by the large upstairs hallway radiator making sloshing/gurgling sound. Being half asleep i just turned it off thinking air etc, but it kept on gurgling so i headed downstairs to the understairs cupboard where the heating manifold and pump are located and instantly smelt the inhibitor.
On opening i found the fluid coming out of one of the lower unused connections. It's a 12 port manifold with the last two being unused, and the cap on one of them which holds the upper pin down was broken releasing the pin and letting the fluid flow out. I've closed of the flow valves, g-clamped the pin down again and switched off the ASHP. On looking at the guilty cap i can't be sure if it was knocked or through time (8 years) it couldn't take the pressure any more. So i should replace them all i'm thinking.
Anyway to the fix. I think i've lost about six litres of fluid and reckon it came out of the upstairs radiator/s and hope that none was lost from the ufh. So i was going to replace the cap and refill the system bleeding the upstairs radiators. Does this sound right? Any suggestions would be much appreciated and i've attached a photo of the set up.

 

[kev25v6]

Bleed the rads upstairs as normal but there should be a bleed valve on the manifold too.

 

[hebridean]

Thanks Kev, and i'll have a look for that valve.

 

[bernardgreen]

Shouldn't the un-used ports be capped.

 

[hebridean]

Thanks Bernard, i was wondering why that wasn't the case. If they had been then i'm sure that this port wouldn't have leaked even with the top pin released.

 

[OvertonPlumber]

We also cap unused ports with small lengths of pipe