Maintenance and servicing gas and electric water heaters
Gas and electric water heaters
Water heaters are little more than giant insulated water bottles with heaters. Most water heaters are fueled by either gas or electricity. It is hard to imagine living an active life without instant access to hot water. As hot water is used, cold water enters through a dip tube.
Gas models, which are most common, use a single burner to heat up to 65 gallons of water. Water heaters are fairly simple appliances, but when problems arise, they can present an array of confusing symptoms;
No hot water.
- Not enough hot water.
- Pressure-relief valve leaks.
- Pilot flame will not stay lighted.
- Water heater leaks around base of tank.
Maintaining a water heater
Standard water heaters are designed for easy maintenance, with removable access panels that allow you to easily remove and replace worn-out parts. Most water heater problems are the result of sediment buildup or rust. You can help prevent this by opening the drain valve every few months and flushing out a few gallons of water. On average, water heaters last about 10 years, but with regular maintenance, they can last far longer, up to 20 years
Repairing gas water heaters
For a gas heater to burn evenly and efficiently, it must have an ample supply of combustion air. If a gas water heater isnít heating water, check the pilot light; Remove the outer and inner access panels to make sure the pilot is lighted. If you canít get the pilot light lid, the thermocouple may be worn out.
Replacing a gas water heater
First make sure your old water heater canít be fixed. If the tank itself leaks, not the pipes, the lining has rusted and the heater must be replaced.
- Shut off the gas and wait 10 minutes. Shut off the water at the shutoff valve.
- Disconnect the gas line, and then disassemble the pipes and fittings.
- Drain the water from the water heaterís tank
- Screws and disengage the exhaust duct, then remove the old water heater.
- Position the control box close to the gas line, the access panel accessible, and adequate clearance around the unit.
- Check the unit with a level, and shim, if necessary.
- Put in place the flue hat, then the exhaust duct. Make sure the horizontal duct hangs at the correct slope.
- Drive one sheet metal screw every 4íí to attach the flue hat to the exhaust duct.
- Install the pressure-relief valve.
Attach a copper or CPVC drainpipe to the pressure-relief valve.
- Solder a threaded male adapter to each water supply pipe.
- Wrap Teflon tape around the treads of two heat-saver nipples.
- Attach the blue-coded nipple to the cold-water ineit and the red-coded nipple to the hot water heater outlet.
- Connect the water lines to the heat-saver nipples with flexible water connectors.
- Test-fit the old gas pipes and fittings, adding fittings as necessary to adapt to the size and position of the new unit.
- Clean the pipe threads, that coat them with pipe joint compound. Assemble and tighten the fittings.
- Alternate if the gas line is flexible copper; use a flare fitting to connect it to the water heater.
- Restore water supply to the water heater.
- Open the valve on the gas line, then test fittings for leads.
- Turn the gas cock to the pilot position, and then set the temperature control to the desired temperature.
- Remove the outer and inner access panels covering the burner chamber.
- Hold a lighted match next to the pilot gas tube.
- Press the reset button on top of the control box, and hold it for one minute after the pilot flame lights.
Repairing electric water heaters
The most common problem with electric water heaters is a burned-out heating element. Every gas heater has one or two heating elements mounted in the sidewall. To determine which element has failed, check the hot water at a faucet. If the faucet delivers water thatís warm, but not hot at any setting, replace the top-heating element. If it delivers a small amount of very hot water, followed by cold water, replace the bottom-heating element. If replacing the heating element doesnít solve the problem, replace the thermostat, which is located under the access panel on the side of the water heater. If your electric heater fails, first check for burned-out fuses or tripped circuit breakers at the main service panel.
Replacing an electric water heater
- When you buy a new electric water heater, choose one with the same voltage as the old model.
- Switch off the appropriate circuit breaker or remove the fuse to turn off power to the water heater.
- Unscrew the retaining screws on one of the heating element access panel of the heater.
- Wearing protective gloves, fold back the installation, Caution: Do not touch bare wires until they have been tested.
- Touch the probes to the top pair of terminal screws. If the tester lights, turn off main power switch and retest.
- Disconnect wires and release the cable from the clamp. Remove the old heater, then position and level the new one.
- Connect water pipes and pressure-relief valve. Restore water supply.
- Tread the circuit wires through the clamp, then through the cable opening.
- Connect the clamp to the unit.
Connect the circuit wires to the water heater wires.
- Attach the ground wire to the ground screw.
- Set thermostat to desired water temperature.
- Press reset buttons on thermostat. Replace insulation and access panel, and then restore power.