How to Fix a Leaking Drain Pipe on a Hot Water Heater

A PVC Connector

Water heaters, which are the vital source for hot water to the home, are designed with a drain pipe to prevent overflows. The drain pipe is constructed of PVC, which is flexible and easy to work with but also susceptible to cracks and leaks. Repairing the bad section of PVC drain pipe involves cutting out the bad section and replacing it with a new section of pipe and connections to complete the repair.

Things You'll Need

• Garden hose (if needed)
• Hacksaw
• Utility knife
• Cloth
• 2 PVC couplers
• Measuring tape
• PVC pipe
• PVC cement

Instructions

1. Locate the leak or crack in the PVC drain pipe on the water heater.

2. Turn the electricity to the water heater off at the main service panel. Locate the labeled circuit breaker switch for the water heater, and flip it to the off position.

3. Turn the main water feed valve to the off position. The valve will be located on the top of the water heater tank and labeled. If you need to drain the tank to prevent water from continuing to leak in the drain pipe, hook up the garden hose to the drain valve at the base of the water heater, and turn the valve on to drain the water heater tank.

4. Cut two or three inches above and below the leak in the PVC pipe, and remove the leaking piece of pipe. Use the sharp edge of the blade on the utility knife to scrape away any burrs from each end of the drain pipe.

5. Wipe both ends of the pipe with the cloth rag to remove any dirt, grim, or moisture that might prevent the cement from adhering to the pipe.

6. Dry fit each of the PVC couplers on the ends of the pipe to get a measurement for the length of the replacement piece of PVC pipe. Slide a coupler over each end of the drain pipes, and measure from the center of one coupler to the center of the remaining coupler. This will give you the length to cut the replacement section of pipe. Remove the couplers from the drain pipe.

7. Cut a piece of PVC pipe to the measurement from step 6. Clean the edges with the utility knife.

8. Apply PVC cement, using the swab that comes with the can, to outside end of one of the pieces of drain pipe and to the inside of one end of one of the couplers. Slide the cemented end of the coupler over the cemented end of the drain pipe, and allow the glue to set for a couple of minutes. Repeat this step to apply the remaining coupler to the remaining end of the PVC drain pipe.

9. Apply cement to the outside of one end of the replacement piece of PVC pipe, and to the remaining inside end of one of the couplers. Insert the end of the pipe into the coupler and allow the cement to set. Repeat this step to connect the remaining end of the replacement piece of PVC pipe to the remaining coupler, and complete the repair. Bend the PVC pipe slightly, if necessary, to slide the final end of the pipe into the coupler. Allow all cemented sections of pipe to cure for an additional five to 10 minutes.

10. Turn off the drain valve at the base of the heater, and disconnect the garden hose if you used it.

11. Turn on the main water feed valve to fill the water heater tank.

12. Turn the electricity to the water heater back on, only after the tank completely fills.

13. Watch the new PVC drain pipe section, and test for any leaks.

Tips & Warnings

• A yearly schedule to drain your water heater will help remove any mineral build up from the water and provide an opportunity to check for other needed maintenance.

• You can purchase a variety of connectors with pre-molded angles to help with any turns in the connection and repair of the pipe.

• Never turn on the hot water heating elements without a full tank of water. This could damage or burn up the elements themselves.

• Avoid direct inhalation of the fumes of the PVC cement as this could cause nausea or loss of consciousness.

References

• This Old House: Glueing PVC Pipe

Resources

• Water Heater Rescue: Water Heater Safety Tips