VERY noisy 6025

[landragon]

I got 1 x 6025, and 1 x 6045 yesterday, from different LFS's. After placing both in my new tank, and filling with ro/di, I plugged the 6025 in. It hummed and buzzed liked nobody's business. I plugged in the 6045. The 6045 is dead silent. I removed the 6025 and disassembled it to look for obstructions, or a bent shaft. I also removed and disassembled the 6045 for comparison. I can't figure this out. There seems to be no visible cause. Any suggestioins?

 

[rvitko]

There is a stainless steel disk under the prop assembly, sometimes this falls off and is loose in the hole. It can also be stuck to the magnet from vaseline used in assembly and pretesting. The first disks were cupped and the cup should face up, the newest ones are flat. Short of that I would guess the shaft is likely crooked, the impeller is the same as the one on the 6045 so you could try swapping them and rule out the impeller that way.

 

[Nizztos]

<a href=showthread.php?s=&postid=10742315#post10742315 target=_blank>Originally posted</a> by rvitko
There is a stainless steel disk under the prop assembly, sometimes this falls off and is loose in the hole. It can also be stuck to the magnet from vaseline used in assembly and pretesting. The first disks were cupped and the cup should face up, the newest ones are flat. Short of that I would guess the shaft is likely crooked, the impeller is the same as the one on the 6045 so you could try swapping them and rule out the impeller that way.

I had the same problem with one of my 6025s being VERY noisy. Thought it was a long shot, but checked the disk and to my surprise it was stuck between the shaft and the sidewall. Got it out, put it back on the shaft and thought the pump had not started when I turned it on, so silent was it after the "fix".

In my case I'm sure I was the one that got the disk in the wrong place as I had replaced the impeller on this one and I must have gotten the disk in the wrong place when putting in the new impeller.