REPLACING PUMP

[ChrisR]

b.o.b. remember that if your replacement pump is the same make as the original you can just change the body - undo allen screws.

 

[oilman]

Then again, if the valves are stuck up, it may well be the waterways in the pump are severely restricted, so you may need a complete replacement.

 

[B.O.B DOLE]

b.o.b. remember that if your replacement pump is the same make as the original you can just change the body - undo allen screws.

thanks chris would i need to drain down heating and hot water cylinder when changing the pump head

 

[ChrisR]

You need to do SOMETHING to stop the boiler water coming out, like draining, bunging or freezing. No the HW cylinder though which isn't connected unless yo have a primatic.

Once the body is off the head you can inspect the rotor. If it's gunged up then oilman's comment is right.

The pump nuts (the 2&1/16th inch ones) can bind on the pump flanges and make it hard to get apart. Yo don't have to do so if you're just changing the body. If you DO have to change the whole pump, it's a lot easier getting hold of the pump head than the whole thing (big pair of grips).
If the pump nuts really bind,cut and split them off.
If your valves are that bad and you care about it, you would be replacing the valves anyway, so just undo the 22mm compression nuts on the valves and dump the lot.

Gate type valves are better than the 1/4 turn ones as a rule but they're a different length, so won't go straight in, usually.

 

[B.O.B DOLE]

once the pump as been refitted would i vent the pump by undoing screw at front and turn impellor

 

[ChrisR]

yep