Quietest Power Vent Water Heater & Tankless mixing valve exemptions

[jborge]

Hi Everybody,
I am looking at replacing my Bvent to make room for some duct work for expanding ac to the 3rd floor.
Noise of a power vent is of concern.  The "Super Flue " by GSW/JohnWood seems to be heavily marketed as a quiet power vent water heater.

From field experience what brand of power vent water heaters are the quietest?

Thank you.

Jan.

[walker]

go with a tankless if you'd want quiet, or insulate the room it is in well.  From my experience from a new tank perspective most brands are relatively similar in noise levels, and some age gracefully while others don't.  In most cases the only time the water heater noise will bother you is at night time, where it's not likely to run anyways. But if I had to chose I would go Rheem or GSW and would run from Bradford White.

[Sergroum]

I have pretty good experience with John Wood. If nothing else, the warranty is a lot easier with John Wood then with Rheem.

But noise wise, they seem to be pretty identical. If you seriously worried about noise, like if you have a bedroom nearby, or the like. The only way to really ensure lack of noise is tankless.

[jborge]

Thanks for the feedback.

So it will be located in the furnace room, next to the furnace.
It is in the basement, but if it was loud, you would hear it upstairs. The Hi Eff. furnace is not that loud upstairs.
No bedrooms close by.

On demand has crossed my mind, just concerned about the added complexity.
I think the scare is from watching YouTube videos, some seemed loud, but could be older models.

[Admin]

A tankless would require minor plumbing work but you would not need a mixing valve.  The biggest concern is a tankless may require a larger gas line.  Most allow 2", 1 pipe or 2 pipe, venting just like most PV tanks.  I find more noise coming from the air intake and burner area than the motor itself on alot of the PV FVIR tanks. How the venting is secured to the structure will affect noise.  Sometimes insulating under the metal strapping that secures the venting helps reduce noise.

One of the only tank type PV models left that meets the Ontario Building Code, 0.8 Energy Factor requirement, is the GSW 6GN5076N.  I don't find it loud, and it has a fast recovery.  It can vent with 2" but needs 3" if you're longer than 10'.  For that money though I would just get a tankless.  I install alot of Bosch 9800 and Rinnai RUC160 and the both seem like good tankless systems.

[walker]

A tankless would require minor plumbing work but you would not need a mixing valve

That depends on the model.   My Bosch tankless required a mixing valve as per our building inspector because the temperature control cannot be locked to disallow set points above 120F.

[Admin]

The Bosch Greentherm 9800 I install has a max temp of 120F but can be reprogrammed to 140F.  I just checked and the manual says,

When the water heater is in operation, temperatures in excess of 120 °F (49 °C) can occur. To limit the temperature at the tap, install a thermostatic DHW mixing valve.

The plumber is getting away without a mixing valve, but should be installing one it seems.

I know the Rinnai has a dip switch to reach 140F but the manual doesn't mention a mixing valve.

[walker]

The Bosch Greentherm 9800 I install has a max temp of 120F but can be reprogrammed to 140F.  I just checked and the manual says,

When the water heater is in operation, temperatures in excess of 120 °F (49 °C) can occur. To limit the temperature at the tap, install a thermostatic DHW mixing valve.

The plumber is getting away without a mixing valve, but should be installing one it seems.

I know the Rinnai has a dip switch to reach 140F but the manual doesn't mention a mixing valve.

I have the previous edition Greentherm the C1050,  there is no dip switches to lock out anything above 120, it comes straight from factory allowing up to 140F.  As long as you can use a dip switch to lock it at 120F and a homeowner can't easily set it above 120F then then the mixing valve isn't required, this is what the building inspector told me anyhow.

[Admin]

I suspect the gas inspector could use Clause 4.1.3 and issue a warning tag on the Bosch 9800 I install because the manual does say to install a mixing valve.

Clause 4.1.3 - An appliance, accessory, component, equipment, or any other item shall be installed in accordance with the manufacturer's certified instructions and this Code.

[Admin]

Bosch sent me a letter that says the Greentherm 9800 does not require a mixing valve, regardless of what the installation manual says.  Also installing screens in the vent terminations is optional.

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