Megaflo cold water dripping from tundish different opinions

[David Grant]

My Megaflo CL170 is dripping cold water out of the tundish. I have recharged the air gap as per manufacturer guidelines and it's then perfect for 2 weeks. After 2 weeks its starts to drip cold water again through the tundish and discharges outside.

I realize the safety implications of working on these units so want to get a qualified plumber out.
After speaking to a few plumbers one plumber has advised it's the PRV if it's cold water. Another plumber has advised it's not the PRV it's your cylinder baffles that have failed so will need an expansion tank fitting.

The current system only has a red expansion tank for the central heating.
I am experiencing no issues with pressure of water or anything just the annoying water discharge.

Anyone any experience of these units as don't want to end up paying for the wrong advice?

 

[ianmcd]

If it stopped dripping for two weeks after re-establishing the bubble, it is unlikely that the PRV is faulty