Sailing home 2/7 - mooring, pressure relief and joker valve

It is late November in 2016 and I fix a lot of small problems, stuff is worn, stuck and clogged, and I try to empty the transom shower system without any luck. I also fix one of the cabin lights since it does not turn on. Jabsco joker valve part nr. 29092-1000 Quick Pressure Relief Valve 1/2" 6.0 bar model FVSLVS126B00A00