CH pump vibrations: any advice?

You shouldn't get anything like that amount. You might have to replace it. However it's far more likely to be unsecured pipework somewhere. All you can do is go around pressing on the pipework and see if the noise goes way. If you find a spot that quietens it, secure the pipework there. You might have to take up floorboards. You can use a large screwdriver as a sounding rod. Blade against the pipework andhandlepressed against your ear.

You might find some thin plywood or wallboard is acting as a sounding board. This can be fixed by installing additional support.

Is this a new problem or one you have just decided to fix? And have you bled the pump?

The latter: I first noticed it a few months ago. but now that the heating's coming on (well as the twice daily water), I notice it a lot more. It's worst when the system starts up (i.e. cold).

Ummmm - no. I looked at doing this, but the pump is "suspended" vertically between sections of pipe in the airing cupboard. This is *way* better that our old system of a few years ago, when the plumber had installed the pump buried under floorboards, however when I used to bleed the old pump (having un-buried it) it was easy because the pump was flat-horizontal, and the bleed valve seemed to be on the top, thus air would escape easily. On this one, seems to me that any air will not escape, because the bleed valve (if indeed that's what it is) is below any trapped air (the pump being vertical). [It's a Grundfos Super-Selectric Type UPS 15-60 130 by the way.]

Sorry: that was a very garrulous answer to a short, simple question.

John

I would still try it. However it seems your problem is expansion noises from the pipework and not than a pump problem.

Still worth doing as the water is a lubricant for the bearings. Pumps don't last long if they aren't bled, one of the yearly preventative maintenace things along with excercising any gate valves.

Pumps do vibrate a bit and this can be carried along the pipework to somewhere that acts as a sounding board. The one for the CH here has a rather firm clamp from the pipe to the floor, can't hear any hum from it next to it but it's very noticeable in the room below. Awaits a tuit.

No, it's a comb> Still worth doing as the water is a lubricant for the bearings. Pumps

Hmm -- I'll have a look at the possibility of clamping mine, then, in some kind of cushioned, vice-like grip. And thanks, both, for recommending the bleeding, despite my reservations.

John

Getting rid of a sound board type amplified vibration can be very difficult. Making everything rigid may well make it worse as transmission of the vibration will be made better. Loosening things is often the way to go but resonances are also often involved. Loosening may enable something to resonate better...

Add miss and add compliance.

Lead and rubber are your friends.

I have a similar problem, only become apparent recently.

I've got the same pump, mounted in a vertical pipe, but pumping downwards, not recommended according to the data sheet. How do you bleed one of these pumps, I can't find a reference anywhere? Is it the big screw on the round face of the pump or what?

You need something with a bit of give in it that is compressible. Old carpet or the real stuff Sorbothane sold to damp out vibrations. Even then you can still hear our CH pump gently humming when it is quiet.

In message , Davidm writes

Not the same pump,

But on my Wilo one, that is where you bleed it.

It might have been easy to bleed but that's not a valid way to install a CH pump. Having the pump shaft vertical will shorten the life of the bearings.

RTFM - the pump shaft should be horizontal, or slope slightly upwards toward the bleed screw. It must not slope downwards. Ideally the water flow should be pumped upwards, although horizontal or downward pumping is permissible, provided that system air vents are provided to prevent air-locking in the vicinity of the pump - all as clearly illustrated in the instructions supplied.

IME if the pipework is securely clipped to something solid reasonably close to the pump then noise will not be a problem. It's where a pump can flap around in loose pipework that you get noise/vibration.

I have never bled a pump because I didn't know you could. On the other hand I have had them last for over 20 years without a problem.

Jonathan