My Grundfos UPS 15-50 pump is only 2-3 years old and still performs very well EXCEPT when starting up each time when it makes a horrendous grating noise for 15 to 20 seconds. Is this likely to be simply repaired?

The pump is in a vertical pipe but pumping down.

Steve D, February 2013

Has enough water in header tank ,it's may be running dry ,if water level OK ,open big silver nut on pump need good screw diver to open let some water come out,keep boiler on ,add water treatment in header tank like sentinel 100 which will make boiler and pump run noise free"...".....oil in car

ltd, February 2013