Follow these six steps to stop overpaying for hot water and improve water heater efficiency.
This guide works for storage tanks and tankless water heaters. Complete each step in order. The full process takes about 2.5 hours.
Before You Begin
- Check your water heater type. Steps 2 and 3 apply to storage tank units only.
- Find your cold-water shutoff valve before you start.
- Let the tank cool for two hours before Step 2.
What You Will Need
Flathead screwdriver, garden hose, thermometer, insulation blanket kit, foam pipe sleeves, a 1-1/16-inch socket wrench, low-flow showerhead, replacement washers, foil tape, and permanent marker.
Time and Difficulty
| Step | Time | Difficulty |
| Thermostat | 5 min | Beginner |
| Tank flush | 35–45 min | Beginner |
| Insulation | 45–60 min | Beginner |
| Leaks and fixtures | 30–60 min | Beginner |
| Annual checks | 20–30 min | Beginner |
| Replace decision | 10 min | Beginner |
Total time: 2.5 to 3.5 hours
Step 1: Adjust the Thermostat to 120°F
a. Open the thermostat panel with a screwdriver. b. Turn the dial to 120°F. Electric units have two dials. Set both. c. Close the panel and wait one hour. Test the water at a faucet with a thermometer.
Pro Tip: Mark the old setting first. This gives you a reference point if you need to adjust again.
Step 2: Flush the Tank to Clear Sediment
a. Turn off the heater. Connect a hose to the drain valve. b. Run the hose to a drain. Close the cold-water inlet valve. c. Open a hot tap inside the house. Open the drain valve and let the tank empty. d. Open the cold inlet briefly to flush out sediment. Repeat until the water runs clear. e. Close the drain valve. Refill the tank fully. Then turn the heater back on.
Warning: Do not restart the heater until the tank is completely full.
Pro Tip: Repeat this flush once a year.
Step 3: Insulate the Tank and Pipes
a. Wrap an insulation blanket around the tank. b. Cut openings for the thermostat, pressure valve, and gas valve. c. Secure the blanket with tape or straps. d. Wrap foam sleeves around the hot water pipes near the tank. e. Seal each joint with foil tape.
Pro Tip: Touch the tank one hour later. It should feel cool, not warm.
Step 4: Fix Leaks and Cut Hot Water Use
a. Check every faucet for drips. Mark any that leak. b. Replace the washer or cartridge in each leaking faucet. c. Swap old showerheads for low-flow models. d. Check washing machine hoses for leaks. Tighten or replace as needed. e. Wash only full loads. Use cold water for laundry when you can.
Pro Tip: Check your water meter before and after two hours of no water use. A change means a hidden leak.
Step 5: Run Annual Maintenance Checks
- Flush the tank. Repeat Step 2 every year.
- Test the pressure relief valve. Lift the lever, then release it. It should stop dripping right away.
- Check the anode rod. Replace it if half worn or coated in white buildup.
- Check pipe joints for leaks or rust.
- Check the burner flame on gas units. It should be blue, not yellow.
For a full yearly inspection, professional Plumbing Services can service your unit and catch problems early.
Step 6: Decide to Repair or Replace
a. Find the unit’s age on its label. b. Compare your last three bills to last year’s bills. c. Replace the unit if any of these apply:
- It is older than 10 years (gas) or 12 years (electric)
- Bills keep rising despite Steps 1 through 5
- You see rust or pooling water at the base
- A repair quote costs more than half of a new unit
A heat pump water heater uses up to 70 percent less power than a standard electric model. A tankless water heater skips standby heat loss completely. Check the Energy Star list for rebates. Then contact a plumber to discuss water heater installation.
Troubleshooting
Water still lukewarm? Check both thermostat dials on electric units. One may have reset.
Water still cloudy after flushing? Flush again. If it stays cloudy, the tank may be failing.
Bills still high after all six steps? Check for hidden leaks first. If none are found, replacement plan.
Quick Reference Checklist
- Thermostat set to 120°F
- Tank flushed and running clear
- Insulation blanket installed
- Pipes wrapped with foam sleeves
- Leaking faucets repaired
- Low-flow showerhead installed
- Anode rod checked
- Pressure valve tested
- Replacement decision made
FAQs
How do I flush my water heater?
Turn it off. Connect a hose to the drain valve. Drain the tank fully. Flush with cold water until it runs clear. Refill the tank before restarting.
How do I know if my anode rod needs replacing?
Remove it with a socket wrench. Check the surface. Replace it if more than half is worn away or coated in white buildup.
How do I check that my insulation blanket is working?
Wait one hour after installing it. Touch the tank surface. It should feel cool. Seal any open gaps with foil tape.