What the heater is telling you
Hot water that isn't right
Most hot-water calls are one of six things. The reading we take tells us which.
Lukewarm
A thermostat set low or failing, a burned-out element on an electric heater, or a mixing valve letting cold in.
Runs out fast
Sediment in the tank takes up room, or a dip tube is worn. A larger household can simply outgrow a smaller tank.
Rumbling or popping
Water trapped under a layer of sediment boils and bumps. Flushing helps; a tank that is old enough may not recover.
Drips at the relief valve
Often pressure: high street pressure, or heated water with no expansion tank to go to. A weak valve is the other cause.
Runs too hot
A thermostat set high or stuck. Most household heaters are set to 120 degrees Fahrenheit; hotter water can scald.
A long wait for hot
Distance from the heater to the tap. A recirculating line or a smaller heater near the far bathroom is the usual answer.
Do this first if the relief valve is discharging
A relief valve is a safety device. If it is running or spitting, the tank is hotter or more pressurized than it should be.
- Keep people and pets away from the valve and the pipe it drains to.
- Turn the heater's thermostat to its lowest setting, or shut off the gas or breaker to it.
- Shut the cold supply valve to the heater.
- Call us when the office opens. Don't cap or plug the valve.
Pressure and heat
Why a pressure problem shows up as a hot-water problem
Heating water makes it expand. In a closed system with a pressure-reducing valve or a backflow check at the meter, the extra volume has nowhere to go.
So the pressure at the heater climbs each time it fires, and the relief valve opens to let it out. We read the pressure at the heater, with the burner running and off, before we recommend a tank, a valve or a new heater.
Pressure read at the heater, burner off and on
Expansion tank air charge checked
Repair or replace, with the reasons written down
Questions about hot water
Should I repair or replace my water heater?
It depends on what the diagnosis finds. A thermostat, an element or sediment is a repair. A tank that is leaking at the seam is not. We write the reasons down so you can decide.
Do you flush water heaters?
Yes, when sediment is the cause of rumbling or short supply. If the tank is old enough that flushing could do harm, we tell you first.
What temperature should my water heater be set to?
Most household heaters are set to 120 degrees Fahrenheit. Higher settings give hotter water faster and can scald.
Do I need an expansion tank?
If your house has a pressure-reducing valve or a check valve at the meter, usually yes. We check the system and say so.
What if my heater is a tankless model?
We diagnose those too. Mineral buildup and gas or water supply problems are the common causes of cold spells.
Hot water acting up?
We read the pressure at the heater first, then tell you what we found.