Noisy central heating pump

[Michael.M]

Hi Guys,

Hopefully, someone can help, had a couple of plumbers out to look at a noisy central heating pump and running out of ideas on this one.

The central heating pump is noisy, sounds like bubbles in the pump so definitely air getting in their somehow, The pump itself has been replaced but the issue not gone away. The pump is a GRUNDFOS UPS2 and the noise is there on any of the three-speed settings. The Radiators and pumps have all been bled and the water is pretty clean that comes out of the Rads (The boiler has recently been serviced and the engineer doing it said it was clean also)

I have done some research and my only thoughts are the pump being upside down could be a problem? Possible leaky pipe joints as there is a small amount of green on the pipe? (Bear in mind, I work in IT for a living so could be a long way off here!)

Any help appreciated, couple pictures attached. One engineer has even recommended replacing it with a Pressurised (Megaflow?) system which I'd like to avoid the cost of!

IMG_6529

• Michael.M
• 18 Dec 2019

IMG_6527

• Michael.M
• 18 Dec 2019

Thank you!

 

[CBW]

Where’s this green you speak of? Also has the air vent on the hot water side been bled?

 

[ianmcd]

your pump is not upside down

 

[Michael.M]

Two more Pics which hopefully help TN, you can see some slight greening around the pipes in Pic 1. Sorry, I'm not too sure on the hot waterside. On the second pic, the pipe that extends up and has the twist cap that twists and lets air out but doesn't resolves the issu - Hope that helps?




Thanks for confirming Ian, shows what I know!

 

[CBW]

The minute amount of green on the pipe appears to be flux residue. The twisty cap as you call it is an air vent - which is what I was referring to.

 

[Mottie]

I don’t know whether this will work for you but I have the same pump. It was fitted on my open vent system which was later converted to a sealed system. I still have it with a new boiler. It always made a rhythmic whooshing/percolating sound every 30 seconds or so that sounded like air going round the system no matter how much it was bled. I just learned to live with it. When the new boiler was fitted, apart from fitting a mag filter, a few weeks later I also fitted a Spirovent deaerator just to ensure there was no air in the system which coincidentally cured the whooshing immediately. I can only assume it did what it said on the tin and removed all the micro bubbles from the system.
https://www.spirotech.co.uk/products/spirovent-microbubble-deaerators-brass/

 

[Michael.M]

Hi motman, thanks, I'll get that looked into as sounds like a cheaper solution than replacing the lot and worth a shot.

I've uploaded a video of the noise its making, to make matters worse the damn thing is installed in a cupboard in the main bedroom! Thanks for everyone's input so far, do appreciate it.

Vid: