Water Heater Concerns

Heater Not working Not Enough Hot Water Proper Size Proper Temperature Scalding Facts Pressure Relief Water Heater Noise Water Hammer Dip Tube Problems Milky Water Earthquake Dangers Links

Heater Not working
If you have no hot water at all and you have an electric water heater, check to make sure the circuit breaker is on and the unit is receiving power. If your electric heater is connected and not producing heat you will have to call for service to determine the cause.

If you have a gas-fired unit, see if the pilot light is on. If the pilot light is out on your gas-fired unit, try re-lighting it. If the pilot light will not stay on, you'll need to replace the thermocouple.

Note: If the pilot light stays on but goes out occasionally, the wind may be traveling through the vent or flu pipe and blowing it out. Make sure there is a baffle installed at the outlet of the flu to discourage this.

We sell these items, but you must know the model of your heater to make sure you buy the correct part. Please consult your owner's manual before attempting any repairs on your heater. Improper repairs could void your warranty. When in doubt, hire a professional technician to service your equipment.

Not Enough Hot Water
There can be many reasons your water heater is not producing enough hot water.

It may simply be undersized for your needs. Analyze the demands you place on the system and compare them to the rating of your heater. You may find that it is not designed to provide the amount of hot water you're trying to extract from it. Be careful about raising the thermostat because you will increase the risk of scalding. (See below)

If a heater has been working fine but suddenly stops producing enough hot water and you have not changed your usage pattern, check for a broken dip tube, a defective thermostat, burned out heating elements (electric), or a heavy build up of sediment. See Rheem's website for more information on these subjects.

Proper Size
Rheem has complex formulas for determining proper sizing for residential and commercial applications, but for most families the decision is not that complicated. Think of all of the activities everyone in your household would likely be engaged in during any one-hour period and add up the total gallons of water these activities would require. The handy table below will give you an idea of how many gallons you use in day-to-day activities.

Compare the total gallons needed with the recovery rate on the heater you are considering.

For example, if you have a family of four and both adults take a shower in the morning while the children wash up and brush their teeth, by the time breakfast is finished, the family will probably have used nearly 40 gallons of hot water. This would require a minimum of a 40-gallon heater.

If you have a large family, are particularly active, or intend to install an oversized whirlpool or a full-body shower you may need to consider an upgrade.

Water temperature will start to drop as hot water is drawn from it. Consumption demands have a habit of growing with time, and with modern bath equipment becoming more luxurious, the needs for an ever-increasing supply of hot water is evident.

Proper Temperature
Some homeowners turn their thermostats higher to increase the availability of hot water when they really should have bought a larger heater. This can be extremely dangerous to small children and elderly or disabled persons

The factory setting on new residential water heaters is 120 degrees Fahrenheit. This is the highest setting considered to be safe; higher temperatures can cause severe scalding.

Below is a Table showing the approximate exposure time for a burns to occur for different water temperatures:

Scalding Facts
COURTESY: SHRINER BURNS HOSPITAL

• Hot water scalds account for 20% of all burns
  
• More than 2,000 American children are treated for scalds each year
  
• Scalding accidents occur most frequently in the bathrooms and kitchens where they are most preventable
  
• Scalding leads to additional injuries such as heart attacks, shock, falls, and serious broken bones, particularly among the elderly
  
• Scalding and other burns require the most expensive treatments: long hospital stays, costly skin grafts, and plastic surgery
  
• Most U.S. states now mandate some form of anti-scald measures in building codes
  

A bathroom sink and shower can be fitted with anti-scald protective devices that are very affordable. These devices are made by all shower valve manufacturers. (see: shower valve manufacturers)

Pressure Relief
As water is heated, it expands. This builds pressure within the tank.

Every water heater must be protected by a pressure-relief valve mounted at the top of the heater, and these valves should always be replaced when the water heater is replaced.

If a there is no check valve, pressure reducing valve, or other device blocking the inlet to the water heater, the increased water volume simply travels back into the source. However, if the inlet is blocked, this pressure can build to dangerous levels.

The relief valve relieves this pressure by discharging sufficient water to bring the pressure down to acceptable levels. If you don't want a pressure relief valve to release this water, you would need to install a thermal expansion tank in the water line to absorb the expansion

Water Heater Noise
As water heaters age, particularly in areas where there is hard water, calcium carbonate can precipitate out and settle to the bottom of the heater in the form of sediment.

As the burners heat the bottom of the tank, steam bubbles form under the sediment just as they do in a pot on your kitchen stove. The steam bubbles escaping from under the sediment create the thumping and popping noises you sometimes hear coming from your water heater.

This build up of sediment can also reduce the efficiency of your water heater and reduce its holding capacity. Regular flushing of the water heater through the drain valve can help prevent sediment build up. Sediment reduces the efficiency of the water heater and may clog pumps and valves elsewhere in the system.

Condensation often occurs on water heaters when a large hot water draw occurs and a large amount of cold water enters the water heater. Sometimes this condensation can be mistaken for a leak in the tank. In addition, this condensation can collect at the bottom of the heater and drip onto the hot burner, causing a sizzling noise. This is not generally harmful.

Water Hammer
Water traveling through the pipes contains kinetic energy. The sudden closing of a valve causes a shock wave in the system, which results in a hammering sound in the pipes.

This is not only annoying, but it's also potentially damaging to the plumbing system. This occurs most often with solenoid valves.

Water hammer arrestors are available to combat this problem. They resemble a cylindrical container with a small air bladder inside, installed near the valve causing the problem. The air bladder cushions the force of the flow of water, thus softening the impact.

Occasionally, a sagging water pipe will behave the same way, and installing hangers or clamps can help to reduce the problem.

Dip Tube
The dip tube is a long slender tube that fits down into the water heater inlet. The dip tube directs the incoming cold water down to the bottom of the tank.

If the dip tube is broken, the incoming cold water can mix with the out going hot water and cause it to seem as though the water heater is running out of hot water.

If these tubes are defective, they can corrode, releasing tiny particles of plastic and sludge through the plumbing system. This in turn can clog the faucet aerators and screens causing low water pressure at the fixtures.

Milky Water
Water contains dissolved oxygen and other gases.

The capacity of water to hold gas is determined by atmospheric pressure. At normal atmospheric pressure, when water is heated, it releases some of these gases because it has less capacity to hold them.

However, a water tank is a sealed environment, so as the water is heated, pressure builds up in the tank, artificially holding these gases in their dissolved state. When water is drawn from a faucet and released from the tank, the pressure is lowered, causing these gasses to vaporize and form tiny bubbles in the water, giving it a milky appearance.

These bubbles are harmless, and if you let the water stand for a few minutes these bubbles will rise out of it and the water will clear up once again.

Earthquake Risk
A 50-gallon water heater holds about 400 pounds of water.

It could also cause a good deal of water damage should the tank lose its contents in the fall. A falling water heater could damage the water pipes and create a costly plumbing repair bill in addition to the water damage.

It could also waste valuable water when local firefighters need every available drop of water to fight the inevitable fires that can accompany earthquakes.

All of these consequences can easily be avoided.

Water heater strap kits are available and sometimes even required by local building codes. These are not expensive and will secure the tank in place and prevent the kind of damage mentioned above.

To read more about these as well as other topics of general interest concerning water heaters, please refer to Rheem's technical bulletins.

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