Are Direct Vent Water Heater Always Special Order?

[KC27]

I am looking to replace a 7 year old 50 gallon Bradford White direct vent natural gas water heater like the one shown below. These are special order items at big box stores. Are there any places that typically have a heater like this in stock?

When I had the Bradford White installed, the plumbing company had me waiting six weeks until they took delivery of the unit than got out to install it. I live in a fairly large metro area - Milwaukee, WI, so I am hoping I can source one faster than the six weeks it took the last time.

Reliability is important. Brand name or place of purchase is not. Any advice would be appreciated.

Thanks

 

[Bannerman]

Many Direct Vent units now commonly use an inducer fan and 2" plastic venting and are equipped with an electronic igniter instead of a pilot light. The combustion chamber on those is not usually sealed but combustion air is obtained from within the home.

I do not observe an inducer fan in your photo example, but as combustion air is provided through the concentric metal vent from outside, that will usually indicate a sealed combustion chamber. If your unit does not require electrical power, then a standing pilot will be utilized.

These differences are the likely reasons why your less common direct vent model may need to be custom orderd. Big box stores usually are limited to the SKUs they are authorized to sell. You may have better success obtaining a replacement WH from specialty plumbing dealers who supply plumbers in your area.

 

[Sponsor]

 

[Reach4]

https://www.supplyhouse.com/sh/cont...er heater?searchText=direct+vent+water+heater

 

[Phog]

As Bannerman notes above, the "Power Vent" style of tank water heaters with PVC inlet / exhaust has become dominant and it is often harder to get the "Direct Vent" style units locally like you're looking for. As you are finding out.

(Someone may point out that "Power Vent" is just a sub category of "direct-venting tank water heater" but for the sake of discussion let's just use the common lingo Power Vent= PVC)

As far as reliability, while nothing will ever beat a pilot system (that doesn't require an external electrical source), however the Power Vent style has become known to be very reliable as well. Igniters & blower fans can go bad but most often seem to last the ~10yr life of the average gas fired tank. The pro's here can probably attest to the fact that by the time those parts are needing replacement it's probably time for a new tank anyway.

One thing you do lose with the Power Vent is that they don't work during an electrical power outage. Some (but not all) coaxial Direct Vent tanks do not require external electric power to run a fan/igniter.

So, if you can't easily source a Direct Vent unit & can live with what's described above you might want to consider making the switch over to Power Vent. At least if you go that route you're buying something that is very common & it will be easy to find a repairman /replacement tank in an emergency in the future. Of course that's a personal choice and you may have your reasons for going with the harder to find style.

 

[KC27]

Thanks for the suggestions. I am really trying to avoid the power vent if at all possible.

I had two power vent water heaters prior to the direct vent water heater. The fans on the power vent units started out quiet, then got noisy as they aged. The house is small, so there was no escaping the sound of the vent fan on first floor, since it was right beneath the floor. In the warmer weather when the windows were open, you would get a double dose of noise from the heater fan in the basement and the exterior vent.

Hope to source it locally, but supplyhouse.com might be the way to go.

 

[Phog]

That noise is a common complaint, some units seem to be quieter than others, but I agree with the Direct Vent being a better choice if noise is your criteria & you don't mind the hassle of sourcing one.

 

[Bannerman]

A further option maybe to install a condensing tankless water heater. Although it too would be power vented, the fan will be shrouded and will only operate while hot water is being drawn.

Benefits would include, higher gas efficiency, elimination of standby heat losses, never ending hot water availability, longer anticipated lifespan and, no floor space requirement, thereby freeing-up additional floor space in a small home.

 

[KC27]

I had my water heater set at 140 degrees F (maybe the temperature setting is why it died after just 7 years). I did not think a tankless heater would not be able to provide water at 140 degrees when the incoming water in the winter is 40 degrees or less. A neighbor has one and loves it.

 

[Bannerman]

The amount of temperature rise achievable, is conditional on the maximum BTU of the tankless WH and the flow rate needed. Many tankless units allow up to 199,000 BTUs maximum gas input, and with up to 98% efficiency, almost all of that heat is transferred directly into the water. Each tankless model's marketing literature will typically specify the gpm acheivable for a specific temperature rise such as your 100 degree example.

Because you will not use 140 degree water for some activities such as showering, much of the hot water to the shower head will be tempered with cold water so the actual hot water flow from the WH will be well below the maximum flow rate possible. Because gas tankless units will modulate the heat output, it will automatically reduce the BTUs when a lower flow rate will require less heat to satisfy the desired temperature setting.

Because tankless only heat when water is being drawn, a small amount of water will initially pass through the WH without being heated. This is not usually noticable unless a hot faucet is repeatedly turned On and Off in short bursts such as between rinsing individual dishes. Some tankless units incorporate a small internal buffer tank to store a small amount of hot water to eliminate the 'cold water sandwich' situation described when flowing hot water in short bursts.

Units equipped with buffer tanks will usually also incorporate a circulator pump to ensure the water in the buffer tank is maintained at the appropriate temperature when no hot water is used. Those pumps may also be configured to circulate hot water in a loop so hot water can arrive at remote faucets without wasting water to drain waiting for hot water to arrive. Depending on your home's layout and degree of finish, it might be possible to add a return line fairly easily if your home is not already equipped.

 

[Jadnashua]

It all depends on your maximum flow rate required and how cold your incoming water will be. Where I live, during a cold spell, my incoming water can be barely over freezing. A tankless system just didn't cut it for me when filling a tub, and sometimes, even taking a shower with the reduced volume.

Generally, with an inline (i.e., tankless) heater, you don't need to try to get 140-degrees out of it. Code calls for distribution to be no higher than 120 except for certain things like washing machines and dishwashers. If yours is set to 140, hope you have a tempering valve installed as well!