Lochinvar Fan Noise-

ced48

At certain speeds, the blower fan makes some vibration related noises. Boiler is a WH 55.



Runs nice and quiet, except at these certain percentages, like 38-39%- Always at these 3, or four different speeds, never in any other ranges. So far Lochinvar has said some noise is normal, but should I be concerned that this noticeable vibration will shorten the fan's bearings lifespan?

SWEI

Try changing

the effective length of the intake pipe.  You should be able to slip-fit something to the outside with a couple of elbows.  See if the resonance point moves.



VFDs have parameters (called "skip frequencies") for just this situation.  Never seen that in a boiler control, but it might not be such a bad idea.

Steve Whitbeck

fan

look into the fan and see if there is anything stuck in it.  I had a sticker unbalance one.

ced48

The Vibration Is

there all of the time, any speed. The vibration can only be felt in the plastic cover, no where else. It doesn't even make the hood vibrate, but there is vibration. At certain speeds it becomes audible.