Can anyone tell me what this adjustable valve is for?
My Warmflow external oil boiler leaks water from this adjustable grey valve at the top of the circulating pump housing. I'm guessing it's some sort of relief valve. The overflow pipe to the soffit coming from the Feed and Expansion tank is also dripping a lot more than previously and the heating system seems noisier than usual when the pump is running, especially when on hot water only. Would this be caused by sludge in the system? I had several radiators replaced last year and the system was drained and refilled three or four times. Inhibitor was used every time and there is a magnetic filter on the boiler. I do have to bleed the radiators a lot though so I'm guessing there's a leak somewhere also. If anyone has recommendations let me know. I can manage the replacement of the pump and the draining and refilling of the system, but I'm trying to understand what's actually happening with it before replacing anything. The pump is working so I'm hoping I don't need to actually replace the pump itself.