Mains vented cylider dripping

[Technotim]

Hi Guy's, I have a horizontal mains vented cylinder in my loft, it is dripping from the pressure relief valve, I have changed the pressure vessel as is was faulty, and also changed the pressure relief valve. recently it has started dripping again, I really am not sure what it is.
I have tried all different pressures in the pressure vessel from 1.5 - 3.5 bar I am not quite sure what the pressure should be in the vessel.
The pressure of the system after the Pressure reducing valve is 2.8-3bar.
I have also flushed through the Pressure relief valve.
My next stage is to replace the new Pressure relief valve as it could be a dodgy one, but I thought I would post on here in case anyone had any ideas.
Thanks in advance Tim

 

[Dan Robinson]

These are dangerous things to be messing with and it is clear you don't know what you are doing.

Call a professional.

 

[Madrab]

Echo what Dan says Tim. You need a G3 certificate to even just breathe on an un-vented cylinder, which is what I assume you mean rather than a "horizontal mains fed vented cylinder".

Do you have your G3 certification, if so you should know about pre-charge pressures etc. If not, it is so dangerous for you and your family if you are playing around with them. Can not stress enough how important it is to get a certified professional in to sort it out if you're not qualified.

 

[Technotim]

Cheers Dan,
P.s I am a plumber Admittedly not mains vent certified.

 

[Technotim]

Echo what Dan says Tim. You need a G3 certificate to even just breathe on an un-vented cylinder, which is what I assume you mean rather than a "horizontal mains fed vented cylinder".

Do you have your G3 certification, if so you should know about pre-charge pressures etc. If not, it is so dangerous for you and your family if you are playing around with them. Can not stress enough how important it is to get a certified professional in to sort it out if you're not qualified.

It is a horizontal unvented cylinder. I had it made by Manco to fit into the eaves space in my loft.

 

[Technotim]

Cracked it, Issue was non return valve in thermostatic shower, the cylinder is old and does not have a balanced cold inlet, so although the pressure reducing valve was working to the cylinder, When I turned on the cold the pressure was shooting up in the cylinder through the shower valve.
Set Pressure vessel back to 3bar same as pressure reducing valve, replaced the hot NRV in the shower and all is well.