Most common questions
How old is my water heater and is it still under warranty? How to read a GSW serial number.
GSW serial numbers contain a lot of information, including when the heater was manufactured. This can be determined by looking at the first four numbers, ignoring any letter that may start the serial number. The first two numbers represent the year the heater was built. If your heater was built before 2008, the next two numbers represent the month. If your heater was built after 2008, the next two numbers represent the week.
For Example
Serial number: U0106413635
This heater was manufactured in June 2001
To see if your water heater is still under warranty click here to go to our warranty validation page.
Please note that warranties are based on use in residential applications.
Reduced warranty for commercial applications.
Why is my T&P valve dripping water? Diagnosing and fixing thermal expansion.
The most common reason a T&P valve is dripping water is thermal expansion. The water in a water heating system expands when it is heated and has a greater volume.
Follow these easy steps to diagnose thermal expansion:
- Turn the heater thermostat all the way down, and install a water pressure gauge with dead hand on the drain valve. Open the drain valve, so the gauge reads system pressure.
- Open a hot water tap and allow 15% to 20% of the tank’s volume to run out.
- Shut off the drain valve and make sure that no other fixture in the system, hot or cold, is open. Make sure that outside fixtures, if they are on the same system, are turned off too.
- Check the water pressure gauge, and turn the pointer so it lines up with the pressure indicating needle. Turn the thermostat back up to its normal position, so the heater cycles on. Watch the pressure gauge.
- If the system is closed, the pressure will start to climb steadily and rapidly. A small amount of thermal expansion control may be built into the system because of trapped air pockets or a water hammer arrestor. In that case the pressure will increase slightly, hold steady for a short time and then rapidly increase.
- The temperature and pressure relief valve (T&P) or PRV should open and release water once the pressure reaches the maximum setting on the valve. The valve will close once the pressure falls below the pressure setting of the valve.
- The PRV is installed between the check valve and the water heating system. The expansion tank is installed between the PRV and the water heating system. Follow the manufacturer’s instructions for installing the expansion tank.
- Run the thermal expansion check again. The pressure should increase only slightly then hold steady throughout the recovery cycle. The expanded water is flowing back from the heater and into the pressurized storage bladder of the expansion tank. Air pressure will force this water out of the expansion tank into the supply once usage resumes.
WARNING: Thermal expansion of water, if not compensated for in system design, will lead to the early failure of components. These failures are not covered by the manufacturer’s warranty, so it is extremely important that everyone be aware of the causes, symptoms and solutions to thermal expansion in a closed water heating system.
How to install a pressure-reducing valve and expansion tank.
The ideal fix involves the use of a pressure reducing valve, if supply pressures are above 60 to 70 psi, and a properly sized expansion tank.
DO NOT DEPEND ON THE T&P VALVE TO HANDLE THERMAL EXPANSION! The T&P valve, according to the makers of those valves, was designed as an emergency relief device only. The T&P could be subject to reduced effectiveness or failure.
I found a puddle of water around my water heater. What happened?
Water accumulating on the floor or in the drain pan is generally caused by one of the following conditions:
- Condensation
- Drain valve leaking
- Temperature and pressure relief valve leaking
- Leak from piping on and near the inlet and outlet
- Leak at gas valve threaded connection (gas models only)
- Leak from gaskets for electric elements (electric models only)
- Leak in heater tank
CONDENSATION: Condensation should only be noticeable after a long draw of hot water. Once the temperature of the tank is above 110oF, condensation should stop.
DRAIN VALVE LEAKING: Check to see if the heater drain valve is closed tightly. If the leakage cannot be stopped by the handwheel, replace the drain valve.
TEMPERATURE AND PRESSURE RELIEF VALVE LEAKING: If the leakage is from temperature and pressure relief valve or its discharge pipe, it may represent relief valve activation. The relief valve relieves water slowly when actuating on pressure. A closed system can cause pressure to increase in the system. This condition is called thermal expansion. The incoming water pressure should also be checked and compared with the valve’s rating. If the supply water pressure is higher than the valve’s rating, a pressure reducing valve will be needed.
LEAK FROM PIPING ON AND NEAR THE INLET AND OUTLET: In warm or humid locations, condensation can accumulate and run down flue tubes, cold water supply pipe, and heater connections. Check connections and fitting for possible leaks.
LEAK AT GAS VALVE THREADED CONNECTION (GAS MODELS ONLY): Remove valve and reapply pipe joint compound.
LEAK FROM GASKETS FOR ELECTRIC ELEMENTS (ELECTRIC MODELS ONLY): These gaskets can be replaced. The element threads may need to be resealed.
How do I determine the proper sized water heater for my application?
Water heaters can often fail prematurely due to improper sizing. The storage capacities as well as the recovery rate are both important factors when sizing a water heating system. Improper sizing can also lead to complaints of not enough hot water. It is important to consider not only the volume of water required, but the temperature that is required. When a large volume of water is needed within a small amount of time, this water is generally supplied from storage. This volume is referred to as the dump load. When choosing the appropriate storage tank size, the actual and usable storage will need to be addressed. If water is required at a certain gallon per minute rate, this water will generally be supplied by the recovery of heater. Keep in mind that any dump loads also need to be included in this recovery.
Some signs of an undersized water heater are:
- Heavy condensation
- Rust chips on the burners and flue tubes
- Not enough hot water
- Premature tank failure(s)
When a water heater is properly sized, some condensation will occur. However, excessive condensation is not normal and will corrode the heater.
What does it mean if my water smells bad?
The most common cause of smelly water is a bacteria that is already present in water, but grows rapidly when kept in a warm water environment such as water heaters or hot water storage tanks. This bacteria reduces sulfates that are also contained in the water to a point where they are converted into sulfides. Sulfides, when mixed with hydrogen produce an unpleasant rotten egg odor called hydrogen sulfide gas. Sometimes, hydrogen is already present in the water and is increased by the anode rod(s) found in your water heater.
Permanently removing the anode rod(s) is not a suggested remedy as this will void your tank warranty.
A solution for this problem is to chlorinate your water heater or hot water storage tank. A chlorine feeder may be the only permanent solution to iron or sulfur bacteria infestation. You can also try changing the anode rod from magnesium to aluminum.
Is having a water softener harmful to my water heater?
The use of water softeners in hard water areas and even moderately soft water areas is becoming a common occurrence. This practice has a potentially detrimental effect on the performance of the anode in the water heater which can cause a reduction in the life of the water heater. Customers using water softeners should expect more rapid anode consumption. Anodes should be inspected more often and replaced when nearing the end of their useful life.
Why do I hear the pipes bang, thump or vibrate when I turn off the water at my sink faucet or when I run my dishwasher/washing machine?
This is referred to as “water hammer”. Water hammer occurs in a piping system when water flowing through a pipeline is stopped abruptly. When water hammer occurs, a high intensity pressure wave travels back through the piping system until it reaches a point of some relief. The shock wave will then surge back and forth between the point of relief and the point of stoppage until the destructive energy is dissipated in the piping system. The violent action accounts for banging, thumping, and/or intense vibration in the pipeline. Although noise is generally associated with the occurrence of water hammer, it can occur without audible sound or noise. Quick closure always causes some degree of shock with or without noise. The common cause of water hammer is single lever faucets (sinks/lavatories) or automatic solenoid valves (dishwashers, washing machines, etc.). The speed of the valve closure time is directly related to the intensity of the surge pressure.
The only effective means of control is to install water hammer arrestors. These devices have diaphragms which separate an air chamber from the water in the piping system. As the shock wave reaches this device, the air chamber absorbs the shock. Arrestors should be located as close as possible to the source of the shock wave.
Why is my gas water heater condensing?
Condensate is the result of airborne water vapour being chilled below the dew point. The dew point is the temperature at which water vapour turns into liquid. Low incoming water temperatures cool the piping and the heat transfer surfaces of the water heater. When the main burner comes on, the hot flue gases turn into condensate upon contact with these surfaces. The typical home water heater will produce about one-half gallon of water vapour during every hour of operation. Condensate is often mistaken for leaking. Newer heaters will condensate more than older heaters because modern water heaters are much more efficient than their predecessors. The newer heaters utilize as much of the energy out of the main burner flame as possible. This lowers the flue gas and tank storage temperature and closer to the dew point temperature.
To distinguish between a condensing water heater and a leaking water heater:
1. Wipe up any water under the heater.
2. Turn the knob on the thermostat to the pilot position.
3. Wait 8 hours, check for water accumulation under the heater.
4. Condensation should stop when the entire tank of water is heated above approximately 115 degrees
If no water is found under the heater, the water heater was condensing.
If water is found under the heater, check further for a loose fitting. If all fittings are tight and the tank is leaking, replace the water heater. Leaking heaters cannot be repaired.
How do I drain and flush my water heater and how often should I do it?
It is recommended that the tank be drained and flushed every 6 months to remove sediment which may buildup during operation. The water heater should be drained if being shut down for extended periods of time.
GAS-FIRED WATER HEATER:
To drain the tank, perform the following steps:
- Turn off the gas to the water heater with the manual gas shut-off valve.
- Close the cold water inlet valve.
- Open a nearby hot water faucet.
- Connect a hose to the drain valve and terminate it to an adequate drain.
- Note: The drain hose should be rated for at least 94°C (200°F). If the drain hose does not have this rating, open the cold water inlet valve and nearby hot faucet until the water is no longer hot.
- Open the water heater drain valve and allow all the water to drain from the tank. Flush the tank with water as needed to remove sediment.
- Close the drain valve, refill the tank, and restart the heater as directed under “Operating Instructions”. If the water heater is going to be shut down for an extended period, the drain valve should be left open.
- Important: Condensation may occur when refilling tank and should not be confused with a tank leak.
- Turn off water supply.
- If floor drain is not near water heater, connect a garden hose to drain valve and direct to floor drain.
- To speed the flow of water, open a hot water tap to let air into tank at a single-handled faucet nearby.
- Allow water to run until water is clear and no discolouration in water.
- Turn drain valve off once water is clear.
- Turn water supply back on. Fill tank with water.
- Make sure tank is completely filled with water. Turn nearby faucet off.
- Check for leaks.
ELECTRIC WATER HEATER:
NOTE: Make sure power is turned off in the case of electric heaters. Electric elements will burn out if they are operated in a dry tank.
Turn off water supply.
- If floor drain is not near water heater, connect a garden hose to drain valve and direct to floor drain.
- To speed the flow of water, open a hot water tap to let air into tank at a single-handled faucet nearby.
- Allow water to run until water is clear and no discolouration in water.
- Turn drain valve off once water is clear.
- Turn water supply back on. Fill tank with water.
- Make sure tank is completely filled with water. Turn nearby faucet off.
- Check for leaks.
- Restore power.
What type of element do I require for my electric water heater?
The element in your water heater could be one of four types: strap-on, plug-in, bolt-on (square flange) and screw-in. The water heater element should be visually inspected to ensure you are selecting the correct element.
