A water heater drain valve can start leaking and give you problems. Sometimes it is the valve itself that is leaking and for older tanks it can be the flange around the valve that leaks.
Not sure if the leak is coming from your drain valve? See the article 'Leaking Hot Water Heaters' to troubleshoot your problem.
There are (3) options for this repair 'Tightening the Valve' would be the first choice, there are some issues. Next, a work around would be 'Capping the Valve Outlet', this can solve small leaks. 'Replacing the Drain Valve' would be a last resort, this is a fairly big job. Read the overview below for genral information.
Drain Valve Purpose
The purpose of the drain valve is of course to drain the hot water heater. Certain repairs that you might need to do on the hot water heater can only be done if you drain the tank. This is especially true for an electric water heater.
The other reason is to perform routine maintenance on the water heater. Hot water tanks should be flushed out peiodically to remove sediment from the bottom of the tank. The drain valve is used for 'flushing the tank'.
Problems With Drain Valves
The ones that come from the factory are plastic and not very durable. You can flush it out and tighten it. This may solve your problem.
The other option is to replace it. Not that big of a job. Oh wait! You have to drain the tank to change it. So it is a little bit of work. You may opt to take the easy way out and just put a cap on it. Is that all right? Are you allowed to do that?
All right, just to prove this isn't one of those internet teaser articles, I'll tell you now. You can cap it. Less than two bucks. Is that great, or what?
When the leak is bad you are forced into changing it. This is less fun, since draining the tank is involved. In addition, most of the factory installed drain valves are plastic and break easily.
The information below will help you determine if you have an easy problem or a little bit tougher one. Find out what you need to do.
Fixing a Water Heater Drain Valve - Information
What Can You Save?
Probably around $150. A plumber will just put a new one in. He has to drain the tank down so it will take him an hour or so. You will feel dumb if he decides to just tighten it and charge you $75.
How Hard Could It Be?
Repairing a water heater drain valve is not that hard. Worst case you have to replace it. Still around and hour.
Check the Simple Things!
Try to tighten the valve, that is pretty easy. Is the leak minor, you can put a cap on it.
What Can Go Wrong?
Breaking the plastic water heater drain valve will require that you replace it. You cannot use the water heater without the valve in place. No hot water is not good news for anyone. You need a hose to drain the water heater down. Remember you have forty or more gallons of water. Take steps to deal with the water.
Troubleshooting a Water Heater Drain Valve
Tightening the Fittings On a Drain Valve
Like most valves, water heater drain valves have washers in them. Tightening the fittings can help the washers to seat better and may stop the leaks. However, there is a danger that the problem could worsen. This is especially true, since drain valves are not the best quality valves, some are even made of plastic.
See the article 'Tightening a Water Heater Drain Valve' for a complete discussion and instructions on what to do.
Capping the Valve for Minor Leaks
For leaks that are not too bad a work around would be putting a cap on the outlet of drain. This can work since this drain is rarely used. Follow the link for 'Capping a Water Heater Drain Valve' to review this subject.
Replacing a Water Heater Drain Valve
When all else fails, you are left with replacing the valve. See the article, 'Replacing a Water Heater Drain Valve' for more information and step by step instructions on what to do.
Summary
Not a whole lot you can do with a water heater drain valve. You can tighten it. You can cap it or you can replace it. How tough was your project? Were you able to tighten it and that was it? That is great news. How about the cap, did that work?
The hardest it could have been was replacing the valve. Did you have to chisel it out? Bummer. Even that wasn't that hard was it? It's just plastic. Now what are you going to do? Does this merit Disneyland? How about another home repair task?