Brand new Rinnai RSC199In making low vibrations during post-purge.

[limenuke0]

Hello. I had a brand new RSC199In installed on an interior wall in my basement. During post purge, the water heater creates a low vibration that can be heard throughout the house. Because I want to have someone renting my basement out, it's important that this machine isn't too loud. I've had a navien before and don't recall hearing this sound.

The RSC199in is mounted to plywood, and the plywood is mounted to 4 studs that I've blocked up a bit. I've also called Rinnai and we've replaced the original fan (warranty), but it was still similarly bad.

I'm about to spend the $$ to have my plumber rip this water heater out and put in a Navien instead. I do worry that the Navien will do the same thing, which is the main reason I haven't had it swapped yet.

I have the tap on for the first 3-4 seconds and then I turn it off. Post purge starts immediately. Video may not have picked up the low vibration

 

[Tuttles Revenge]

My guess would be fan or debris on the fan

 

[Sponsor]

 

[Bannerman]

Was the prior Navien installed at the identical location, or an alternate location such as a solid foundation wall?

Any hollow partition wall will act similar as a drum, effectively amplifying all vibrations created by any mechanical device which is securely attached. Because the wall's wooden support structure will be directly attached to the home's wooden structural members above, vibrations from the partition wall will be transferred directly to the home's other wood members.

 

[limenuke0]

There was no prior Navien - that experience was from my parents' place with the Navien on an external wall.

I had a large tank water heater before.

I think the best solution is to add either vibration mounts or perhaps get the water heater to stand off the floor instead. Maybe I can fabricate a floor mount and just use a strap to secure the water heater to the wall to meet seismic code.

 

[bingow]

... installed on an interior wall in my basement. During post purge, the water heater creates a low vibration that can be heard throughout the house.

Similar experience here with our Navien. Found a couple of pipes or connections touching the drywall. Repositioning them away, and/or inserting a piece of foam between, helped. Adding vibration mounts would have surely helped, but the call-back labor charge would have been steep. Another option is blown-in insulation, which is my next choice, but what we have now is tolerable. FYI we used blown-in insulation from Lowe's for the attic and exterior walls, and are very pleased with the results.