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?