hob noise

my hob filter whisper 30-60 has started making a noise and befor i try a new impeller i thought id ask if anyone else has heard this noise. its a errrr noise close to a rattle sound. it has somthing to do with the way the intake tube sits over the impeller because when you pick up on the intake tube, the sound goes away. but i dont see where the impeller is hitting into the tube. any ideas?

 

You need to clean the impeller. A good overnight soak in distilled white vinegar, then a quick clean with a toothbrush, and you should be good to go. Also, if you can drain the filter and fill up the area that contains the pump (with the impeller still in place), then you will be able to clean the area where the impeller rests. Either one, or both, of those areas needs a good cleaning and that is most likely why you are hearing that noise. Or at least that's what has worked for me in the past.