Boilermate SP Bypass Valve Leaking

Hi

The Bypass valve on my Boilermate SP is Leaking from the red plastic end.

Is this something that can be repaired or do I have to replace it. If I tighten it the leak lessens but does not stop.

Is it something you would recommend doing yourself.

Money is tight so replacing it myself is an appealing option.

Thanks for any advice you can offer.

this valve is a 3 bar over pressure release valve ( for your safety) , so no repair, fit a new one. also have a close look at your expansion vessel, 1 bar air pressure required, ( testing only with the system pressure on zero!!!!)
regards Mario at Mario's Boiler Service