Recharging Air Gap on MegaFlo CL300

[OMS2000M]

Hi.

I replaced the Pressure and Temperature relief valve on my MegaFlo CL300
(I had thought it was dripping but it turns out the overflow drip is coming from the 3bar safety relief valve for the red expansion vessel)

Before I replaced the valve it would recharge the air bubble normally - the tap would run for a short time and then I would open the valve for 10min+ to drain down.

Now however the tap runs for about 10mins without opening the valve. When it finally stops opening the valve does nothing further.

If you open the valve before draining or whilst the tap is running hot water comes out as you would expect.

Very confused as would have expected air needs to be let in to allow water to flow out?
I am assuming as the relief valve is functional this is not a safety concern?

Thank you in advance.

 

[Chuck]

I strongly recommend that you employ a plumber qualified to work on unvented systems (the so-called G3 qualification) to sort you out. Unvented systems are dangerous when faulty or badly maintained and, with respect, you don't seem know what you are doing. Check your building insurance policy, your DIY efforts may have invalidated it.

 

[OMS2000M]

I strongly recommend that you employ a plumber qualified to work on unvented systems (the so-called G3 qualification) to sort you out. Unvented systems are dangerous when faulty or badly maintained and, with respect, you don't seem know what you are doing. Check your building insurance policy, your DIY efforts may have invalidated it.

Understood and trying to do that in parallel now. Any advise or steps I should take to ensure safe in the interim appreciated.