Hot water heater FAQ

water heater scale build-up

Hard water scale build-up (concrete-like) shortens heater life and gives you less hot water.


With over 125 years of water heater service PDM has answers to your problem.

Safety tips for leaking water heater.

If the leak is major:

1. Shut off fuel supply (gas or electric)

2. Shut off cold water supply to the water heater

3. Open all hot water faucets in your home

4. Attach hose to drain valve at the bottom of water heater and drain unit of all water

5. Call PDM Plumbers for quick help.

Electric water heater.

Check fuse or breaker, reset or replace if necessary. Another reason for no hot water could be that the thermostat or element may be defective.

Gas water heater.

Make sure gas supply line is turned on. Remove the inner and outer burner access covers and check to see if the pilot light is lit.

Not enough hot water.

Check the thermostat setting, it may be set too low. But be careful, a hotter setting can lead to scalding within seconds. Check the dip tube, if the dip tube has broken or fallen off, incoming cold water will be drawn out through the hot water outlet without being heated. Other possible causes are clogged burners and low gas pressure. If older heater, scale build-up can be a problem.

Slow hot water recovery.

Sediment buildup in bottom of heater, flushing the water heater may help. Other possible causes may be insufficient combustion air caused by insufficient ventilation, a clogged flue (could be dangerous and allow carbon monoxide poisoning), or improper burner operation.

Pilot light is lit.

Turn on a hot water faucet and let the water run. Check to see if burner comes on. If not run the hot water several more minutes. If the burner still does not come on the problem could be a defective safety system. Check to see if the control valve knob is in the “on” setting and not set to the “pilot” position.

Pilot light won’t stay lit.

Sometimes a draft will blow the pilot light out. Make sure the burner access covers are in place. Other possible causes are dirt in the gas line, or a gas safety device problem.

Pilot light is not lit.

Follow the instructions posted on your water heater and attempt to re-light pilot with care.

Make sure gas valve is open. If the pilot light will not re-light, the problem could be that gas is not reaching the water heater or a clogged pilot line. Call a licensed plumber for help

If the pilot light will light but does not stay lit when the gas valve control is released the problem could be a defective pilot safety switch or perhaps a loose pilot safety switch connection to the gas control valve. Make sure the pilot safety switch connection to the control valve is tight.

Burner flame noisy (whistling).

Problem may be improper gas pressure or dirty burner orifice.

Yellow flame

Problem could be scale on top of burner, dirty burner orifice, flue way clogged or improper gas pressure.

Burner flame floats

Problem may be improper gas pressure, wrong orifice or clogged flue.

Discharge from temperature and pressure relief valve.

The relief valve will open when the water temperature is to high or if the pressure gets too high. If the inlet to the water heater is fed directly from the water main with no pressure relief valves or check valves between them then when the water heater heats the water and it expands, the extra volume of water simply flows back toward the water main. If however there is a blockage such as a check valve or pressure reducing valve with a defective bypass then the increase in water volume has no where to go and the pressure with increase dramatically. Placing an expansion tank in the line at the inlet will give the increased volume of water someplace to go and prevent operation of the relief valve.

Another possibility is that the City water pressure has increased above the setting of the relief valve. Again the installation of an expansion tank will solve the problem.

Popping or banging noise.

Scale can build up in the bottom of the tank causing all sorts of noises to occur while the water heater is heating water. Try flushing the tank. Make sure you turn off gas or electric before flushing.

Sooting

Combustion air inlets or flue-way is restricted or not enough ventilation air supplied to room. Also, may be improper gas pressure or dirty burner orifice. Remove obstruction or debris from heater or flue way and improve ventilation. An obstruction could create carbon monoxide poisoning.

Hot water smells like rotten eggs

Certain types of bacteria can react with the magnesium anode rod resulting in a rotten egg odor. Clean the tank using chlorine bleach or by changing the anode rod to aluminum usually will solve the problem. If older heater, you’re better off replacing with new efficient unit.

Rusty or black water

Anode rod may have dissolved or there is excessive sediment build-up. Check anode rod. You may be better off replacing tank with an energy efficient model.

Milky water

May be as simple as aerated water. Allow a glass of hot water to set for a few minutes. If the water turns clear, the condition is a natural occurrence. If not, call PDM for help.

Leaking tank.

Replace the water heater with energy efficient model. The savings in energy can help pay for the heater. PDM Since 1885 offers same day replacement and a variety or warranties are available.

Call PDM Plumbers for water heater help.