replacing central heating/hot water pump question

[garygrant]

My central heating and hot water pump is not working properley, it is very noisy and vibrates quite a bit, it is quite old now so i believe it is failing. i want to replace it today whilst i am off, but have a question if i may ask:

can i just replace the pump head by removing the 4 allen key type screws in each corner, or do i need to replace the whole body as well and probably drain down my system if the isolation valves fail?

if i replace the whole thing is there an easy way to know if the isolation valves are working properley or not as i don't want to spill much water in the airing cupboard!

 

[cmother1]

What type of isolators have you got? If they're the ball type that you operate with a big screwdriver, as long as you can give them a quarter turn they should shut off. Watch out for them weeping around the shaft after you open them again though.

If you've the older gate-valve type keep turning clockwise until they are completely closed. Expect them to drip a bit even when they are.

PS You will need to replace the whole pump.

 

[garygrant]

Hi

Thanks for your reply and help.

I have the allen key/hole type vales, so the ball type I believe?? What should I do then, if they leak on re-opening? Just drain down and replace?

But what about if they don't shut off... is there a way I can check before getting soaked and undoing the pump unions ??

 

[gaspro1981]

don't even bother trying to turn off the 1/4 turn ball type valves they will leak every time

what is the make and model of the pump that you wish to replace

once you have isolated the pump valves slacken of the screws holding the pump head to the body and you should collect about a pint of water thats all any more and you will know if your pump valves are fooked

 

[twgas]

don't even bother trying to turn off the 1/4 turn ball type valves they will leak every time

what is the make and model of the pump that you wish to replace

once you have isolated the pump valves slacken of the screws holding the pump head to the body and you should collect about a pint of water thats all any more and you will know if your pump valves are fooked

 

[garygrant]

i'm a little confused now!!

i have a red grundfos pump it sahs 15-50 on the label/front of it. if i buy another grundfos 15-50 can i just replace the head instead of undoing the whole body?

if i do have to replace the whole body, any tips toi remove it easily and to check before removing if the isolation valves are shutting off ?

thanks.

 

[mickyg]

if you've got ball type valves as mentioned they will almost certainly leak.
you can only replace pump heads like for like, so unless your existing pump is fairly new its unlikely your gonna get a straight swap. There are adaptors available for mixing but they tend to be a bit sh1te.
tbh your best bet would be purchasing a new pump, 2 new valves(gate type are million times better but beware they may be longer and require pipe cutting) & a bottle of inhibitor. Drain the system down, and if you've got some play in the pipe you can undo the compression fittings on the end and remove the whole lot in one hit, or if no play just cut the nuts off the pump with a hacksaw and do it that way.