Gloworm 30cxi boiler rumbling like a car engine

[festive]

Seems intermittent but more frequent as of late it's rumbling like an idling engine under the stairs, alot of low frequency osilating going on. OF course only makin the noise when the boiler fires up, normal when heating rads.

The Boiler is a Gloworm 30Cxi about 2 years old,

 

[Agile]

A low frequency rumble is usually the result of a worn impeller bearing on the pump.

This results when the water is not very clean and contains fine magnetite in suspension. Usually the result of the system not being power flushed as required if it was dirty.

This will be heard all the time the pump is running !

But NOT only when the boiler is firing up. Turn off gas and it should continue.

Solution is to change pump head and clean the system water.

Tony

 

[gas4you]

Do you mean it doesn't make the noise when on for heating, but does when on for HW?

 

[festive]

Thanks for your replies:

I just tried it now, isn't making noise for CH or HW. So it's intermittent alright, but i definately hear it more than a few times a day, normally when CH is fired up though.

 

[Agile]

A bit of back tracking there!

To identify or absolve the pump I would recommend that the pump head is removed and inspected for bearing movement!

Tony