[Richard 01903]

Hi
Ive lost pressure all of a sudden , Think it might be unloader valve???
when I turn bypass tap instead of hearing engine under strain !! Theres no change
Any help please

[Mike Halliday]

When you turn the bypass tap does it stop the flow Through the bypass pipe?

So you turn on the bypass tap, pull the trigger on the lance and nothing comes out? If so the pressure is still bypassing or no water is entering the pump.

 check the return pipes into the water butt,  clean your inline filter