I have a Myson Unit Five (pale blue in colour) central heating pump that as stopped working, 240v, 1-50hz, 0.49A, 115W, Code 4 89. What can I replace it with?

Robert J Croker, January 2006

I tried to run the heating boiler in my house and everything works fine except that the Myson Unit five pump was not working. I unscrewed the screw to release the flow and some water started to come out. When I tried to screw it back in, I couldn't. It remains turning in a band without pressing firmly so water continues to come out. Can you help me know how to tighten this screw properly?

Juan Campino, July 2020

grundfos 15-50's are the best ones

billybob, March 2010