This. Mine does it all the time since we turn off the WH when not in use. Chuck
That is most likely the issue that you have. Water heaters are designed to have an air bubble in the top which minimizes the pressure changes. Because air is water soluble, that bubble does go away if it is not replenished from time to time. There are several easy ways to do that and easiest is when connecting the fresh water hose, drain out water from the hot water faucet until the air is gone each time as the air passing through the water heater will stay there if it is low. Occasionally a water heater safety valve will start to leak and need to be replaced. It is the brass valve near the top.
Ok, I turn mine off as well when not in use.
Yes, I opened the outside access panel like in the above picture, but I didn't see any drips or leaks inside.That is most likely the issue that you have. Water heaters are designed to have an air bubble in the top which minimizes the pressure changes. Because air is water soluble, that bubble does go away if it is not replenished from time to time. There are several easy ways to do that and easiest is when connecting the fresh water hose, drain out water from the hot water faucet until the air is gone each time as the air passing through the water heater will stay there if it is low. Occasionally a water heater safety valve will start to leak and need to be replaced. It is the brass valve near the top.
An easy way to check to see if that is what is leaking is to open the outside access and watch it for dripping.
The only time it would be dripping is when you are getting the water that you have seen outside. If I am right about the cause that will only happen when it is heating back up from a large amount of hot water usage. That problem is the most probable cause of an intermittent water leak.
This is simply the water expansion pressure exceeding the pressure relief valve release pressure causing it to open and leak water which will result every time the tank heats up from a colder water temp to the hot water setpoint temp. You can briefly crack open the hot water side of a faucet during this heating process to keep this from happening.
RV water heaters use the same pressure relief valves as in buildings. However, water heaters in buildings have expansion tanks (or at least per code they should)...even though they only typically get filled once and stay continuously heated. Water heaters in RVs often don't have expansion tanks and are typically filled/emptied many times and are not typically continuously heated...hence the RV pressure relief valve leakage issue...and all the more reason they should have an expansion tank. Furthermore, and unlike the water heaters in buildings, RV pressure relief valves are frequently manual cycled...when they are opened/closed when draining the tank for Winterization and when they are opened/closed when filling the tank for camping season to ensure the tank is adequately filled so the electric heating element doesn't self-destruct when it is turned ON. The proper solution is to install an expansion tank if a RV tank water heater lacks one. While tankless water heaters also require a pressure relief valve, they don't require an expansion tank since a faucet is always open when they are actually heating and supplying hot water.
The answer is that they can but are much less likely to if you flex them occasionally, which usually doesn't happen with a house water heater. If you want to drain and flush the water heater, as one should do at least annually, the quickest way is to open that relief valve. Also, the reason for letting it snap shut rather than easing it is to seat it better. If you were to read the instructions that come with a new water heater for a house you would find that it says to turn it off, turn off the water, connect a hose to the drain connection on the bottom, then open the drain valve and also the pressure relief. A plumber friend who is also an RVer once told me that if we would do the maintenance suggested for a home water heater, most of them would last at least 5-10 years longer.
As long as the air in the top of the tank is maintained you won't need to do that.
True, but that is a bandaid solution just like cracking a faucet while the tank is heating. Air gets absorbed by water. It also takes more effort to accomplish this and if you don't get it right, you risk exposing the electric heating element to air and burning it out. The other issue is having a wet air pocket in a tank that's just looking to rust out. You need both air (oxygen) and water to create rust. Water tanks last longer when kept entirely full of water with low air entrapment.
