Fitting a water pump

[Rolyan]

I hope to replace an old Myson Compact CP53 water pump, with a new one (just bought it). Usual old central heating system, primatic cylinder, gas fired boiler, etc. There are 2 isolation valves, one each side of the pump. I would like help with three questions if possible:

1) how do I know if the isolation valves are the type you screw down fully to close, or just do a quarter turn. Also, there appears to be a locking nut on them that needs to be loosened, is this correct.

2) is it okay to do this rather than drain the system (which I would like to avoid if possible).

3) assuming I turn the valves off successfully, is the correct procedure to simply disconnect the wiring, undo the large nuts (I think they are 1 1/2" BSP), remove the old pump, replace the new one (wired up), screw the nuts back tight, then open the isolation valves.

Your comments would be appreciated before I flood the house and/or electricute myself.


I'm not a lover of plumbing (having had a couple of 'accidents') and I'm not over keen on electrics, but this seems a relatively simple job. Is it, or am I just foolg myself.

 

[kevplumb]

if the valves are 1/4 turn they usually have a screwdriver slot on them if not close them as they are gate valves not a locking nut its the gland dont slacken it
they usually leak but if its not much and you are quick you can get away with it
replace the sealing washers
the biggest prob is the nuts
they either come off easy
or fight to the death

have fun

 

[Rolyan]

Cheers kevplumb.

The valves dont have a screwdriver slot, they are machined square on the top of a small (approx 1/4" bar) so it sounds like one you close fully.

Really basic question this, but do I use an adjustable spanner for the large nuts on the pump, or is there a special one.

Thanks.

 

[bripl]

many a late night spent beating the Sh*t out of them never seems to be the accessable easy ones always 10ft in the air or behind the cly or hidden under the floor bastidious plumbers