Vibration from combustion blower on P2700 - Normal or out of balance motor?

Recently installed P2700 with a horizontal termination. Last week I decided to abandon it and just spent 2 days doing a virtual installation.

I'm noticing a loud hum which is coming when the combustion blower is on so it does it even at startup.

The hum is actually a vibration which is transferred to the pelletvent pro pipe and finally into the wall that the pipe wall brackets are attached to. If I grab the pipe and grip it real tightly, the hum is reduced dramatically.

This has me thinking that either the blower is out of balance or I need to find rubber grommets of some sort to try and insulate the transfer of vibration to the wall.

Any ideas?

As an experiment, I disconnected the wall brackets and propped the vertical span of pipe up by the bottom of the cleanout tee with a brick. Wouldn't leave it like that for long but the hum is cut in half. However, it is still far too loud and far more noticeable than the room blower on full.

This just can be normal. Other than that, it's running perfectly.

Maybe some pieces of rubber between the house and backets would help?

Brand spanken new.

Rubber between the brackets and the house might be acceptable if the vibration went away with it, but isolating the vent like I did only made it lessen. It's still pretty loud.

I opened the right side cover to look at the combustion blower. The motor itself is vibrating *very* strongly. When you touch it, its enough to make your fingertips go number within a few seconds.

When powering off the unit, I looked at the motor spin down after the shutdown cycle had ended. It was pretty obvious that the cooling fins on the motor itself(not the blower fins) were warped severely. That in itself does not prove a balance issue, but it sure looks suspicious.

Could have, but you'd have to ask the workers who assembled it at the factory since that's where the blower was installed, right?