What's Causing My Hot Water Heater To Overflow Constantly?

If your hot water heater is constantly overflowing and discharging water, it can be frustrating, costly, and lead to water damage in your home. But what exactly causes this problematic issue to occur? By understanding the most common culprits behind frequent hot water heater overflows, you can properly diagnose the problem and take steps to stop it.

With some maintenance and troubleshooting, you can get the situation under control.

Check the Age and Condition of the Water Heater

One of the most common reasons behind constant water heater overflows is simply an old, worn out unit. The average lifespan of a traditional hot water heater is only 8-12 years. As the appliance ages past this point, the tank and parts become vulnerable to corrosion, leaks, and functionality issues.

Signs your overflowing unit is expired include:

• Corrosion or rust spots on the exterior of the tank
• Small leaks from the tank, pipes, or fittings
• Loud rumbling or banging noises during operation
• The water heater is over 10 years old

If your water heater shows multiple signs of wear, it may be time for a replacement. Installing a newer, more energy efficient tank-style or tankless model can restore reliable hot water supply and stop overflows related to age and corrosion.

When to Repair vs. Replace Your Water Heater

While replacement is the fix for an expired, leaking unit, repair may be possible if issues are minor. Things like fixing small leaks, replacing fittings, or adjusting elements and thermostats can sometimes extend the lifespan of a water heater.

As a general rule, if your water heater is over 8-10 years old and experiencing multiple performance issues or leaks, replacement is likely the better solution. This eliminates the risk of more problems down the road.

Inspect the Pressure Relief Valve

Another prime suspect for frequent hot water heater discharges is a worn out or faulty pressure relief valve (PRV). The PRV is an essential safety component that releases water pressure from the tank if it builds to dangerous excess levels risking explosion.

Ideally, the PRV only opens in emergency pressure spike scenarios. However, as it wears out over time, a faulty PRV can activate at standard pressures. This leads to regular water drainage and overflow from the hot water heater as a result.

Warning signs your PRV is behind frequent overflows include:

• Dripping or small leaks from the PRV
• Corrosion on the valve
• Water discharge when no hot water is being used

Replacing an older PRV showing these red flags can stop this cause of overflow. Be sure to pick a pressure relief valve rated for your water heater's tank capacity and pressure.

How to Replace a Faulty Pressure Relief Valve

While a plumber can replace your PRV, with the right tools it's also a DIY project for handy homeowners. Just be sure to carefully follow safety warnings in your appliance's manual.

The general process includes:

1. Turn off power and water supply to the water heater
2. Drain the tank completely through the drain valve
3. Disconnect and detach the faulty PRV from the tank
4. Install new PRV using provided gaskets/fittings
5. Refill the tank and verify no leaks

Take precautions against burns, and be ready to capture any residual water that may spill out when removing the old valve.

Ensure Proper Water Level in the Tank

Maintaining the right water volume inside the storage tank of your hot water heater is also vital for preventing regular overflows through the PRV or side pipes.

Check your appliance's tank for marked "low" and "high" water lines. The level should always stay within this safe zone. If it drops too low, this can cause the heating elements to activate excessively and dangerously overheat.

Low water supply can also cause the PRV to discharge more often. With less volume and pressure pushing down, steam and pressure buildup occurs more easily. Monitoring water levels and refilling when needed prevents this.

How to Refill a Water Heater Tank

Refilling the inner tank when levels run low is thankfully a quick process:

1. Locate the cold water inlet valve near the tank bottom
2. Connect garden hose and open valve to begin filling
3. Allow tank to fill until water reaches "full" marker
4. Close inlet valve and disconnect hose

Keep an eye on the initial refill to check for any leaks around inlet fittings or from the drain valve at tank bottom. Tighten connections or make repairs if needed.

Address Sediment Buildup in the Tank

In addition to insufficient water volume, excess solid sediment collecting at the bottom of the hot water heater tank can lead to overflows and discharge issues over time.

Although many modern tanks have protective linings, mineral scale from household water supply along with metal and limescale particles still accumulate gradually. Too much sediment buildup displaces needed water capacity in the tank, while also leading to internal corrosion.

Prevent this by flushing your hot water heater tank at least annually to remove sediment. More frequent flushing may be needed in homes with heavy limescale or mineral deposits in tap water.

How to Flush a Hot Water Heater

Flushing a tank water heater to remove sediment is a straightforward maintenance task. Key steps include:

1. Turn off power and water supply to water heater
2. Connect garden hose to tank drain valve
3. Open drain valve completely to release water & sediment
4. Allow tank to fully drain, capturing water/debris safely
5. Close drain, refill tank, and restore power when complete

Caution should be taken to prevent injury or burns when flushing. Wear gloves while operating the drain valve and use buckets or pans to capture expelled water safely.

Adjust Household Water Pressure

Checking your home's overall water pressure from the main supply line is also wise if dealing with ongoing hot water heater overflow.

Most tank water heaters include factory pressure relief valves rated for safe operation at pressures between 50-80 PSI. If your household supply pressure exceeds this consistently, it can overwork the water heater and contribute to regular pressure releases.

purchase an inexpensive water pressure gauge that connects to outdoor faucets or taps. Take measurements at different times of day when demand on your home's plumbing is highest.

Consistently high measurements over 80 PSI indicate a pressure reducer is needed. Otherwise, strain from the intense pressure can lead to PRV activation, leaks, and overflow discharge.

How to Reduce Water Pressure

Many homes can benefit from installing a whole house water pressure regulator. This adjusts supply pressure to safer PSI levels.

Options include:

• Pressure Reducing Valve - Install near water meter to lower entire home's pressure
• Expansion Tank - Helps mitigate pressure spikes to appliances

Plumbers can properly size and set pressure regulators and tanks to maintain consistent 50-60 PSI to protect the hot water heater.

Inspect Temperature Settings

Checking your appliance's temperature setting is also important if dealing with water heater overflows. Excess heat causes added pressure buildup needing release.

On a tank water heater, locate the external thermostat dial or display panel. Hot water systems are often set to around 140degF-150degF from the factory. While warm water is desirable for tasks like washing hands and dishes, such intense temperatures increase pressure in the closed system.

Adjust your water heater's thermostat down to a 120degF-125degF range. This still provides sufficiently hot water for needs, while preventing frequent pressure activations of the PRV.

How to Change Hot Water Heater Temperature

To adjust your appliance's temperature setting:

1. Locate external thermostat dial or digital display panel
2. Use screwdriver/buttons to lower temp setting to 120degF
3. Give unit time to adjust internal tank temperature
4. Check household tap water to confirm safe warmth

Take caution not to set the water temp excessively cool. Aim for at least 120 degrees to prevent risk of bacteria.

Check for Corrosion Damage

Corrosion of internal tank walls, piping, fittings, and valves is another condition that can lead to persistent water heater overflow issues over time.

As components corrode from normal mineral and chemical wear, small holes and breach points develop. This allows heated water and pressure to escape the tank inconsistently.

Signs of corrosion damage include:

• Small leaks from fittings, pipes or tanks
• Rust colored water discharge from valves
• Loud noises from heater during use

For older tanks with moderate corrosion, inspectors can sometimes apply protective epoxy coatings to damaged areas as a temporary remedy. But extensive corrosion necessitates full water heater replacement.

Causes of Corrosion in Hot Water Systems

What makes corrosion happen internally over time? Key reasons include:

• Chemical composition of household water supply
• Sediment buildup abrading tank walls
• Age and thickness of protective linings
• Infrequent draining and flushing

Choosing more corrosion-resistant tank materials and maintaining good flushing practices helps longevity.

Diagnose and Address Electrical Issues

For electric hot water heaters, incorrect voltage or related power problems can also be behind overflowing issues.

Voltage surges or shorts from storms, wiring issues, or general wear alter the heating elements' function over time. This affects internal heat and pressure regulation, sometimes forcing the PRV to discharge water.

Warning signs include:

• Unit making buzzing/sizzling noises
• Heating elements not getting hot
• PRV leakage when power is on
• Tank taking longer than normal to heat

Use a multimeter to check your electric water heater's voltage and amperage circuits for abnormalities. Install a whole house surge protector if issues are found.

Why Proper Voltage Matters

Electric water heaters rely on consistent 220-240V power to run heating elements and thermostats. Without steady, clean power supply you may experience:

• Spikes and surges damaging internal parts
• Sediment buildup on failing heating elements
• Overheating risks
• Eventual PRV discharge from excess pressure

Consistent electrical voltage prevents damage that can lead to overflows over time.

Diagnose and Address Gas Supply Issues

On gas-powered tank water heaters, problems with fuel supply can manifest similarly with overflow discharge and insufficient hot water.

Gas leaks, low inlet pressure, or clogged lines starve the appliance of clean fuel for the pilot light and main burner to fire correctly. This sparks pressure regulation problems internally.

Indications your unit has underlying gas supply issues include:

• Pilot light repeatedly goes out
• Burner not igniting fully
• Rotten egg "sulfur" smell
• Higher than normal energy bills

Thoroughly inspect all gas connectors and pipes leading to the water heater for leaks. Verify inlet gas pressure meets appliance needs. Clear any obstructions restricting flow.

How Much Gas Pressure is Required?

Check your water heater manual for needed gas pressure levels. Typically:

• Natural Gas Heaters: 5-14 inch WC supply pressure
• LP Propane Heaters: 8-14 inch WC

Pressure readings outside this indicate repairs needed to piping, meters, or restrictors limiting flow.

Schedule Regular Maintenance

One final but essential tip for preventing constant water heater overflow issues is remembering to schedule annual maintenance for your appliance.

While most homeowners focus maintenance on HVAC systems, hot water heaters also need regular upkeep to identify issues leading to overflows and other operation problems.

Tasks your technician will perform include:

• Inspecting all valves for wear and leakage
• Checking burner function on gas models
• Monitoring all safety controls
• Testing pressure levels
• Flushing sediment from tank
• And more...

Catching and addressing small issues early on prevents major overflow situations down the road.

To stay proactive, create a maintenance calendar for your hot water heater. Follow this schedule:

• Annual pro maintenance checks
• Monthly water level inspections
• Seasonal water heater flushing

Calling a technician out at the first sign of problems can help minimize costly overflow damage over time.