Originally Posted by terratravelr
I believe there's water in the tank, when I open the outside overflow valve water comes out. also, the owner's manual says that if I turn on the hot water side of a faucet and water comes out, then I have water in the tank.
Actually, that's not always true. You can get water from a faucet without having water in your water heater.
If your water heater has a bypass system you can set the valves so that water will bypass the water heater and flow directly to the fixtures without actually passing through the water heater. (Hence the name "bypass".)
Ensure that your bypass valves are set to the normal - non bypass- mode. This will cause water to fill your water heater before being directed to the fixtures.
If you don't know which valve is which (there should be three valves in the bypass system), follow these steps:
- Ensure that all the valves at the water heater bypass system are closed. This is usually true when the valve handle is perpendicular to the pipe. It is also usually true that you turn the valve clockwise to get to this position.
- Ensure that all fixtures are off, both hot and cold.
- Turn on the water pump and allow pressure to build up until the pump shuts off.
- At the water heater, open one valve. Listen to the water pump. If it runs for a long time (1-3 minutes) before shutting off, then you have just opened the valve IN to the water heater. Label this valve. You are filling the water heater with water.
- If the pump either doesn't run or runs only for a brief time (10-60 seconds), open the hot side of any fixture. If the pump starts and continues to run, and water flows from the fixture, you have just opened the BYPASS valve. Label this valve.
- If the pump remains off after you have opened the hot water side of a fixture, you have just opened the valve OUT from the water heater. Label this valve.
- Close the valve you just opened.
- Continue with each valve until they are all identified.
- Note, that once you open the IN valve, the water heater will have water in it so the pump will not run for 1-3 minutes anymore. The water heater will not be full, however, because the air has had no place to go. The air won't leave the water heater until the OUT valve and a hot water fixture are both open at the same time.
This does get complicated, but if you understand the system's operation you can work through the valves. Remember, you only have to do this once.
To set your water heater up for normal operation, close the BYPASS valve and open both the IN and the OUT valves. Open the hot water side of a fixture and allow the air to escape to fill the water heater. After water flows from the fixture, the water heater is full. Close the fixture and start the water heater.
If you have started the water heater with no water in it, it is probably damaged. The extent of that damage and its repair is another issue.
You said that you got water from the outside overflow valve. I assume that you mean the T&P safety valve that is spring-loaded closed and has a lever on the top to allow you to open it. If you did get water through this valve, your water heater has water in it.
Good luck. I hope nothing is burned out.