EHEIM Universal Pump 1048

I made an order in an e-shop in Greece and because of the unavailability of this part I bought at the same time from the Aquaristik shop. After a month I had in my hand two of these pumps. I had to connect one of the pumps in the cooling circuit and after that the water started to run inside the tank through the chiller.

The system had running without problems for about two months and then the pump was started to make a mechanical noise. Day after day noise tended to be louder and louder. I tried to clean and lubricate all the parts like propeller but nothing. So finally I put around the pump two leaves insulating foam, and the noise decreased but not disappeared.

The noise level was enough annoying, so I replaced the pump with the other one. After two months the same happened. Neither the lubrication with the original lubricant spray of eheim, neither the good cleaning of all of the parts of cooling system helped me enough. The noise remains until now.