Plastic insert mounted inside the support unit wore out. Could not buy just the plastic pieces so I had to replace the entire support.
Remove the two small screws from the back of the top cover.
Remove the three star screws from the bottom cover - you will need a special long shaft for this.
Remove top and bottom covers and set aside.
Remove the four star screws from the boiler - these have nuts on the bottom which you will need to hold with a small wrench to fully remove.
Carefully lift up the boiler assembly and remove the bottom support.
Replace the bottom support taking note as to the proper orientation - so that the sump tightens when turned to the right.
Re-assemble the boiler, top and bottom covers.
Note: If this piece needs to be replaced the valve and valve spring should probably also be replaced at the same time.