[kc27]

Even though it costs more, and is a special order item, I would like to get a 50 gallon direct vent natural gas water heater.

Are there any instances where this is not a good idea? A couple of plumbers have suggested I stay away from them. One gave the reason that they are not really commonly used anymore, power vent units are typically installed.

The other said that back-drafting and problems keeping the pilot lit were typical problems with direct vent units. They don't exhaust properly, and condensate get back into the exhaust and combustion area and causes corrosion.

My installation would be next to an exterior wall in an unfinished basement. I currently have a power vent unit in the same location that vents horizontally through the block wall. I'm interested in a direct vent unit because I would like to eliminate the noise of the power vent fan.

Any ideas and especially experience you can share about direct vent water heaters in general, or the pros and cons of direct vent vs powered vent water heaters, would be appreciated.

 

[ddawg16]

Ok....lets put down some basic understandings of vents....

Direct Vent....The combustion air for the heater comes from an outside source.....in some cases, a double walled exhaust tube is used...hot combustion gases go out the inner tube (pipe) and air for combustion is sucked down the outer liner. In other cases, there is a seperate pipe to the outside to provide combustion air.

B-Vent ...double wall pipe....the combustion device draws air from the existing envioronment...aka...room air.

Basically....a direct vent unit uses outside air for combustion.......'potentially' improving effeciency because it is not using heated room air. Whereas, a B-vent unit is will draw heated air from the room for combustion.

I guess a lot comes down to which school you subsribe to.....if you think rooms should be super air tight...go direct vent....but if you feel that a little bit of air replacement is good....B-vent is the way to go.

BTW....if your one of those worried about radon....Direct Vent is NOT the way to go.

 

[kc27]

Following up on this really old thread in case someone else has a question about direct vent water heaters. I had a Bradford White 50 gallon direct vent water heater installed in March 2013. I've had no issues with it - it works great. The biggest benefit to me is that it is quiet. My previous water heaters all were power vent units, and I was tired of the noise of a fan running time the heater fired up.

The down-side is that atmospheric (connects to a chimney) or power vent units are the only water heaters that are kept in stock. One of the previous owners of my home had removed the chimney in my home, or I would have gone with your standard, every day water heater. The direct vent model had to be special ordered, and took 4 weeks to arrive.