A local contractor installed a new furnace and water heater for me on 1/21/2013. The install appeared to go well. The furnace is keeping our house warm and the water heater runs without making crazy noise and it is producing hot water. All is perfect in the world, well not quite…
While checking out the water heater (AO Smith GDHE-50) I noticed that the lower side connect was quite cold, the brass drain was very cold too. My three other water heaters never exhibited anything like this when they had hot water in them. The valve and the side connectors were quite warm when the unit was at standby.
To quantify how much cold water is in the heater I did the following experiment. Immediately after the unit completed a heating cycle (120F, 8F differential) I turned the water heater off. I then closed the cold water value to the water heater and opened a hot water faucet to allow air into the system. Then I systematically drained a gallon of water at a time from the water heater drain and took its temperature with a digital thermometer, repeating until I hit water that was 120F. My best guess at starting was that there is at least 16 gallons of fairly cold water in the heater as each vertical inch is just under a gallon of water and the side connector is 16″ off the floor.
The water heater had 11 gallons of water < 60F. The results of this experiment indicate to me that something is wrong. Past water heaters, I was able to get very hot water instantly out of the drain.
OK, so what’s the problem as long as we have hot water coming out the top? Bacterial growth in the tank. See http://www.treehugger.com/green-food/is-it-safe-to-turn-down-your-water-heater-temperature.html
This looks like the ultimate petri dish.
American water heater company, the maker of the water heater I installed issued me a return authorization number for the water heater that would not run when installed per the instructions. I installed the new one (1/5) and this one works better (it will start), but still not great. It makes noise when starting and the flame is quite yellow and has bad shape. I have posted videos of the start and flame for technical support to look at.
This is the replacement unit starting : http://youtu.be/_Bb3IgamFdo
I contacted technical support again via email and sent them video footage of the poor flame. After a few days technical support contacted me again and FedEx’d me a smaller orifice to try, a #30. The heater comes standard with a #29. I got this smaller orifice and installed it and the unit ran very poorly http://youtu.be/ml-uqXvCrp8
At this point I gave up, I contacted a local contractor and scheduled an install of a new furnace and water heater. I was done trying to make this water heater work.
The replacement water heater was returned to Lowe’s for a refund. Lowe’s was very helpful throughout this very frustrating experience.
Ben, a plumber from K&S came by and spent 3 hours going over my install and inspecting the water heater. He found nothing wrong with my install, whew! After talking to technical support we got the unit running by removing the intake and restricting the exhaust. We had hot water, but the install wasn’t going to pass code as it deviated from the installation instructions.
Water heaters go virtually unnoticed, that is until they don’t work!
As I was unable to correct the negative pressure causing my atmospherically vented natural gas water to back draft at start, I decided to replace it. The 15 year old AO Smith 40 gallon, 40K BTU water heater had absolutely no issues, except that it left our house hold yearning for more hot water.
Obviously a new atmospheric vented water heater was out as it would exhibit the same problem as the old one. What other options are there?
- Atmospheric (what we had)
These are the old type that have existed since the beginning of water heating. Burner on the bottom with a flue up the center which has a draft hood and vents out a chimney. Exhaust is very hot because of low efficiency and it naturally rises and vents out the chimney.
Sealed combustion, used outside air for combustion. Non-powered (no electricity), horizontal and vertical venting with special pipe within a pipe with very stringent requirements. Not used very often as the water heater basically needs to be right against the wall. This is basically an atmospheric water heater with sealed venting and are typically not very energy efficient.
Sealed combustion, requires electricity, horizontal and vertical venting using plastic pipe. These have a wide range of efficiency ratings.
Open combustion which uses inside air, requires electricity, horizontal and vertical venting using plastic pipe. These have a wide range of efficiency ratings.
Since 2003 water heaters have Flammable Vapor Ignition Resistant (FVIR) technology. This prevents home owners from blowing up their houses due to heaver than air explosive vapors. This has caused water heaters to rise dramatically in complexity and price. It has also been the cause of class action law suites.
As I was trying to mitigate a negative air pressure issue, I went with a powered direct vent. I purchased and installed a 50Gal 60K BTU Powerflex Direct (PDVG62-50T60-NV) from Lowe’s (ref.) . My dad and son helped with the install and after about 6 hours it was ready to go. I filled it up, went over the check list and then plugged it in. The gas was lit by the hot surface igniter and then it sounded like a rapid sequence of explosions and then the unit would turn off. This was repeated twice more and the unit got stuck in lock out. I called technical support and after talking for a while we decided to have a plumber come out and take a look, but that would be the next day!