Grundfos CH Pumps.....

[GRW]

My CH Pump (25yo or so old) - is trying to roll over and die on me.
Last couple of days, it's sort of stuck and ticked.
Switching from lowest to middle speed setting got it going first seizure, then from middle to fastest setting 2nd time. No options left, and it ain't gonna get better!

I've never paid any attention to one - is it likely to have carbon brushes (& if it does, can they be replaced)?
If not, I assume I'm looking at at least a partial rad system drain-down (hot water cyl too??), fight the old pump out, fit a new one and refill the system, add Fernox etc?

Ta muchly in advance
G.

 

[voipio]

25 years isn't bad going for these pumps. Does it have quarter turn isolating ball valves on either side of the pump connectors/adapters to 22mm copper, or whatever? If so, a drain down shouldn't be necessary. There are no brushes in these pump motors.

 

[Bornfree]

I bet the new one you replace it with won't last 25 years

 

[GRW]

25 years isn't bad going for these pumps. Does it have quarter turn isolating ball valves on either side of the pump connectors/adapters to 22mm copper, or whatever? If so, a drain down shouldn't be necessary. There are no brushes in these pump motors.

It has what looks to be isolating valves yes.... but if they were to stay on the piped to hold the water in..... the I'm not sure how exactly the pump comes off! Looks like you'd have to slacken the pipe compression joints top & bottom - so you could rotate the brass piece with the valve in, to unscrew it off the pump maybe??

(Yes, no complaints about the lifespan of the pump, its done very well... but if I could swap brushes and/or a capacitor and keep it alive longer, I'd be happy)

 

[GRW]

 

[brightspark]

best to drain it and fit new isolating valves on the new pump. old ones look manky and the glands will probably leak when they are moved

 

[Neilj]

There's a big brass hex nut on each isolation valve where it meets the pump body, these slacken off with the valve stationary and there's just a fibre or rubber washer between the valve and the pump. Undo both nuts and the pump slides out of the gap.
Your only likely problem, as @brightspark has already said, is the isolation valves might not close properly or they might be seized. They don't look healthy so I'd be tempted to do a drain down and change them as well as the pump.

 

[Kayos]

There is zero chance of those valves sealing, more than likely to snap as well

I'd drain and swap the lot, cheap pumps on eBay are your best bet, your system will not like an ERP pump

 

[GRW]

There is zero chance of those valves sealing, more than likely to snap as well

I'd drain and swap the lot, cheap pumps on eBay are your best bet, your system will not like an ERP pump

ERP Pump??? (As I'm making obvious, I'm not a plumber ). I'm reasonably capable of waving spanners with assorted curses though, and the leccy side is no prob.

 

[GrahamGKD]

Last time ours played up I isolated it either side, took the four alen screws out (with something under it to catch the water in the pump), removed the motor and impeller, cleaned it out and put it back - that seemed to do the trick. Only worth trying if your isolating valves will work though?

 

[Bornfree]

ERP Pump??? (As I'm making obvious, I'm not a plumber ). I'm reasonably capable of waving spanners with assorted curses though, and the leccy side is no prob.

Energy related products. because the old reliable ones used too much energy. Said absolutely no one.

 

[Kayos]

Energy related products. because the old reliable ones used too much energy. Said absolutely no one.

Except a fifth, or 20% of the entire worlds output of electricity is used for pumps, that's an easy win to make them more efficient

 

[knighty]

buy a pump and valves, be ready to swap the lot out...

but before you drain the system down try turning those valves off and see how they do... they might be ok, and it'll save you a load of work


when you turn the valves back on (or fit the new ones if they're no good) turn them all the way on then turn them back a touch - stops them jamming

 

[GRW]

Energy related products. because the old reliable ones used too much energy. Said absolutely no one.

Ah! Sod that, I'll have a traditional one anyway given the chance! It's 80 watts of intermittent pump - I don't think I'll be responsible for Armageddon if I don't use some short-life, over-complicated piece of carp instead of a proper pump

 

[GRW]

buy a pump and valves, be ready to swap the lot out...

but before you drain the system down try turning those valves off and see how they do... they might be ok, and it'll save you a load of work

when you turn the valves back on (or fit the new ones if they're no good) turn them all the way on then turn them back a touch - stops them jamming

I do that with all the stopcocks etc anyway already, so yes, will do

 

[Bornfree]

Except a fifth, or 20% of the entire worlds output of electricity is used for pumps, that's an easy win to make them more efficient

Around 10 years ago we started fitting inverter booster pump sets on our poultry sites to save energy. We now fit standard pressure switched/ expansion tank sets because of the reliability.

 

[pedrobedro]

My CH Pump (25yo or so old) - is trying to roll over and die on me.
Last couple of days, it's sort of stuck and ticked.
Switching from lowest to middle speed setting got it going first seizure, then from middle to fastest setting 2nd time. No options left, and it ain't gonna get better!

I've never paid any attention to one - is it likely to have carbon brushes (& if it does, can they be replaced)?
If not, I assume I'm looking at at least a partial rad system drain-down (hot water cyl too??), fight the old pump out, fit a new one and refill the system, add Fernox etc?

Ta muchly in advance
G.

A couple of years ago our pump stopped working. I took the big threaded bung out the front and turned the inside spindle with a thin screwdriver and it's been good ever since.

 

[GRW]

Thanks for all the info folks.
I'll have a tentative test of the valves to check the situation. If I'm jammy and they are operational, I'll seeing I can isolate and poke the pump about a bit.
I ought to get another pump though - its only a matter of time....

 

[123hotchef]

I have one of those pumps here from when i switched out to a combie

 

[brightspark]

A couple of years ago our pump stopped working. I took the big threaded bung out the front and turned the inside spindle with a thin screwdriver and it's been good ever since.

if they havent been run all summer they sometimes stick just t.wat it with a hammer and they free off sometimes