Flow through a stopped pump.

[jobloggs]

My circulating pump is needs replaced. However I want to relocate the new pump on the flow side of the boiler.

Rather than struggle to remove old pump and valves and makeup the gap in the pipework in an awkward place I would like to know:

a. Has a typical impeller pump a high resistance to flow through it when it is stopped? Ie could it just be left in position and wiring cut?

b. How easy is it to dismantle a typical pump in situ, remove impeller and reassemble? I assume without the impeller there would be little or no resistance internally if rest of pump body is left in place.

Thanks in advance to anyone who takes the trouble to answer such an odd query.

 

[chrishutt]

How easy is it to dismantle a typical pump in situ, remove impeller and reassemble? I assume without the impeller there would be little or no resistance internally if rest of pump body is left in place.

Sounds like a reasonable idea. The pump head will be held in place by 2 or 4 screws. Undo these, pull off head, break off impeller, refit.

However I can't see why removing the old pump is so difficult. You're draining the system anyway to fit the new one. Just cut the copper pipe either side of pump valves, fit new section of pipe using compression or soldered fittings.

 

[ChrisR]

you could re-use the nuts which were on the pump valves, on new compression couplings with a piece of pipe between. There are 2 threads around, so you might be unlucky, though 90% of them are the same.
If you were careful you could use the piece of pipe you remove to put the new pump in!
It would be tempting to just break off that impeller...!