Heating Hot Water . . .with your PILOT
Sometimes significant waste occurs when systems have to be set up to accomodate the heaviest uses. For example, in our homes, we flush urine away with the same amount of water that is required to flush away a bowel movement. This fact of life is true with gas hot water heaters.
The typical gas hot water heater has a 3" flue to vent exhaust gases even though an opening that large is only needed while the burner is operating. For the remaining time, when only the pilot is burning, a far smaller vent opening, if any at all would be needed. Not only does this mean that the heat that is generated by the pilot light is for the most part wasted as it goes up and through this 3" vent, but what's worse is that this vent prevents you from heavily insulating the top of your hot water tank where most heat is lost.
I have discovered that in homes (or apartments) with only 1 or 2 people, using less than 40 gallons of hot water per day, the pilot light itself can generate enough btu's to heat the water to an adequate temperature provided the entire water heater is heavily insulated, especially the top. I have done some research as to the potential harm of having the small amount of fumes from the pilot light prevented from being vented, and have found varying views on the subject. Although stoves and other appliances have operated in homes with unvented pilots for years, a much smaller vent opening could be left for operation in homes that are well sealed. A carbon monoxide detector would also be useful to help determine if any risk is present.
The point is this: if you cover up most or all of the top vent and then cover the entire tank with a very heavy layer of insulation, you should be able to heat your water without the burner ever turning on. In order to try this, you must set your control to "pilot only" so that there would be no chance that it would kick on at any time by itself. {A very heavy layer would provide an R value of at least 20 to 30}
My purpose in writing this is in hopes that others who are in the position to test this will do so and thereby validate my claim. I have tried it the last two places I lived and it worked perfectly. I found that I even had to add a small amount of cold to take a shower after leaving the tank to "recharge" all night.
B sure you consider the risks of whatever fumes are generated by the pilot light, and be sure that once the top is covered with insulation that there is no possible way for the hot water heater burner to accidently kick on.
I appreciate any thoughts or comments you might have and hope to hear back from you after you try this yourself. You can follow a discussion on this topic that includes several success stories by going to this forum at ecommoder.com".
Remember these other points to consider: If you are connected to a municipal gas line, you are no doubt charged a monthly connection/service fee whether you use any gas or not. This could mean that $20 a month in gas is costing you $40 a month on your bill . . . or $4.00 for only using your pilot would still cost you as much as $24.00 / month more or less based on your companies rate structure. Also, if you have an electric water heater but use gas for space heat, you may want to disconnect service for the 6 to 7 months it is not needed. They may charge you a substantial reconnection fee, but it is still usually much less than the monthly service fees you would be paying when adding them all up.
