Self regulating Circulating Pump CP50 making noise

[busybee2024]

Hi Everyone,

My Circulating Pump CP50 is making a loud noise. The noise only occurs when the hot water or heating is turned on. I'm making an assumption that there is an air lock in the system somewhere, it happened last year but eventually went away. As it is self regulating the only instruction I've found is to keep turning it off and on again.... Are there any other ideas? The noise it's making is a bit like a loud engine noise. I've attached a screenshot of the pump I have.

Thanks for any advice! Sorry if posted in the wrong area.

 

[Johntheo5]

What mode & setting is it on, post a photo of the pump (while running).

 

[busybee2024]

Hi John, thanks for the response, I've set it on the middle setting, I'm away with work, but should be able to post a photo by tomorrow morning, didn't expect such a quick reply

 

[Johntheo5]

The top row shows the mode, from the left...proportional pressure PP, constant pressure CP & (the traditional) constant curve CC (mode)
the bottom row shows the setting, 1,2&3. 1 is lowest, 3 is highest, so the mode & setting LEDs should (might) both be illuminated.

Have you any link to that model??.

 

[busybee2024]

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This is the link to it I believe, thanks

 

[Johntheo5]

I had that link but have always found it difficult (never) to get a link to your model.
Anyway, post on your settings tomorrow or whenever.

 

[busybee2024]

Taken a couple of photos of the Circulating Pump below. Am I right in thinking that the settings are tied to the size of the property or not related?

The noise is loudest when I set the pump to 3 and the far right setting then lowest at 1 and the far left setting.

Thanks again for any help

 

[Johntheo5]

That setting is constant pressure CP 2 which shouldn't be the cause of your noisy operation IMO, the pump curves below are from a older version and doesn't have constant pressure control, the far right setting on yours is constant speed CS and CS 3 will be the loudest at a 6M head, dont know how many rads you've got but you could try it in (far left) PP mode setting 3, doubt if setting 2 will be enough except you have only 5 or 6 rads.

 

[busybee2024]

Thanks John we've got more than 6 radiators, 10 in total. So I'll change the pump speed to 3.

Any thoughts on what the noise could be? I don't know how I can get rid of air in the system as this is a self regulating one, and doesn't have a mechanism on the side of it to let air out like others do.

 

[Johntheo5]

I don't think air in the pump is the problem even if you can't vent it manually, mine (a Wilo) is the same and there is air vent button that you press which speeds the up and down etc, I've never used it, even when I installed the pump.
Have you a sealed or open vented system?

 

[busybee2024]

It's an unvented system

 

[Johntheo5]

Are you venting any air from the rads?, also ensure system pressure is 1.25 to 1.5 bar cold.

 

[busybee2024]

Just bled the radiators and pressure on the boiler is showing 1.2. I've got a guy coming over next week to take a look at it, so hopefully he can find out what the issue is then I can always post it in here if not resolved before then.

 

[Johntheo5]

Are you getting air/gas from them? If so could be result of corrosion releasing hydrogen.

 

[busybee2024]

Hi John, no don't believe so, radiators were only put in about 2 years ago as was boiler and everything as did a whole house refurb.