Vibration Dampeners for Tankless Water Heaters

[WorldPeace]

To minimize the noise stemming from the vibrations from my tankless water heater, I am intending to install vibration dampeners (aka anti-vibration mounts).

Someone had recommended Barry Controls, Series 22001 in another forum. They're $15 each.

Are there other mounts that anyone can recommend to minimize vibrations, that are better or cheaper? Would any rubber grommets suffice?

 

[wwhitney]

That design is what I used to good effect for the same purpose. Don't omit the snubbing washer.

Not sure if you'll find anything better or cheaper, but if you do I'd be interested.

Cheers, Wayne

 

[Sponsor]

 

[Fitter30]

Where do you think its coming from piping or the unit?

 

[WorldPeace]

Fitter,

It's just the normal vibration from the unit whenever it heats the water. I guess it's coming from the fan?

The tankless is located next to a room in which people are working/studying so I want to minimize the noise as much as possible. People have recommended using vibration dampeners. So, I was hoping there might be people who had experience using them.

Where do you think its coming from piping or the unit?

 

[wwhitney]

For me it was definitely the fan noise. Then fan shifts to much higher speed for a few seconds whenever a water draw stops, presumably to offset the sudden cessation of cooling from water flow as it cuts off the gas burner. Putting it on isolators made a big difference--it had been rigidly mounted to the studs and sheathing, which I think made the wall a bit of an amplifier.

Cheers, Wayne

 

[bingow]

For @WorldPeace and @wwhitney , I would consider doing the same for our 6 mo old Navien NPE-240A, but am ruling it out as not worth the uninstall/reinstall labor cost (installed by a pro; under warranty). Don't see how it can be done otherwise?

 

[Fitter30]

Whats the wall made out of?

 

[bingow]

@fitter30 , 2x4 studs, drywall, uninsulated, on a concrete slab: the wall forms one end of a 2'x6' bump-out utility closet. The Navien is mounted to ⅝" thick plywood, lagged in turn to the studs. I've also considered DIY blown-in insulation from the opposite side of the wall.

 

[Fitter30]

Just out of curiosity if hot water line is insulated put a rag on in grab both lines see if sound changes. If it does and have some angle iron 1/2 x1/2 or 3/4 x 3/4 over 12" long with three stainless hose clamps per piece close to the heater. This will change the harmonics of the pipe.

 

[bingow]

@fitter30 , thanks for the tip. I did a quick groping and fondling of the insulated hot water line while the internal circulating pump was on and saw that it was in contact with a section of the CPVC PRV line, which in turn had been pushed over far enough to make contact with the wall. Later today, I'll experiment with some scrap pieces of insulating foam to lessen the contact. To reposition the pipes themselves looks like a lot of work, but I won't rule it out. Thanks again.
UPDATE: added foam pieces so that there is no contact with the wall except the foam itself, and there's maybe a subtle change for the better. It is still noticable, but tolerable. Can't see putting any serious $ into remounting. But I'm interested to see if the isolaters mentioned above help. Thanks again.