Wilo Gold Class F pump replacement/repair?

[F Giles]

I have had to remove the pump from my central heating/hot water system as I suspect a fault as it was overheating. Unfortunately the ball isolating valves are seized and I need to replace them.

Q. 1.

Can I connect the pump to the mains to test the operation of the pump?

Q. 2.

Should I replace the ball valves with gate valves?

Q. 3

What replacement pump should I choose?

 

[SimonG]

Yes, but spinning in fresh air isn't the same as spinning under working conditions.
Yes.
Grundfoss.

 

[F Giles]

Thanks for reply.

I see in google search for 28mm pump valves figures in the specs in the form 300X292. The digits vary for other valves although they look similar. What do these numbers mean and how can I find them for my old valves?

 

[Dotty]

28mm pump unions are pretty common, go have a chat with your local plumbers merchants in the morning, lift a new pump at the same time.

 

[F Giles]

That's OK jf one has a local merchant! I haven't.

 

[Dotty]

Where are you mate?

 

[F Giles]

Northern isles.

 

[DirksPlumbing]

Northern isles.

Well give us a bit a better understanding what you do with the pump maybe you get a bit better advice what to use.
As for the pump valves, definitely yes replace them with gate valves if you can. But keep in mind that gate valves are slightly longer.

 

[F Giles]

Thanks for that. It would be easier to fit ball valves if gate valves are longer, leaving the existing olives in place and avoid cutting the pipe.

is it possible to free the old valves using penetrating oil or even vinegar? (our water is very hard)

 

[Best]

Usually you can get the large pump nuts to slacken if you tap their flat faces with a hammer. You may need to eventually hit them fairly hard & you need a lot of patience. Personally, if you are going to change the entire valves, just replace with the gate valve type, even though you might need to cut a pipe shorter. If the nuts on the pipes are seized very badly (rarely would be that bad) you could cut them on an angle using a junior hacksaw with a new blade in it, on opposite sides of the nut & split it off with a slotted screwdriver. Provided the water is drained obviously.