It’s the forgotten appliance, but when you have gas hot water heater problems it can be very inconvenient. Most water heater problems are pretty easy to fix and some are impossible to fix.
I’m going to stick to tank type storage water heaters for this article because storage water heaters are much easier to trouble shoot and repair than tankless water heaters. They pretty much consist of a tank of water over a burner with a thermostat. They are pretty simple and very reliable.
Tankless water heaters are sophisticated high tech appliances. The tankless units have multiple sensors to monitor things like incoming water temperature, outlet temperature, exhaust temperature, and water flow all feeding information to an internal computer. The computer controls things like modulating gas valves and water flow valves. There are error codes and many models even have remote controls.
Typical problems you may encounter with your water heater are things like the pilot light going out or it won’t re-light, pressure relief valves that leak or drip, broken or damaged dip tubes, worn out anode rods, and leaking tanks.
Pilot light problems
Usually pilot light problems are a result of a bad thermocouple. The thermocouple sits directly in the flame from the pilot light and glows red from the heat. The thermocouple generates a small electric current from the heat and the current keeps the gas valve open.
If the thermocouple goes bad the pilot light will not stay lit. Replacing the thermocouple is relatively easy. Usually it’s held in place by a nut. It’s a small tubular shaped metal object with a small diameter metal tube which ends with a fitting that screws into the gas valve.
If the pilot light stays lit, but the burners won’t come one, check to see if the flame is bright blue. A weak yellow flame may not get the thermocouple hot enough for the gas valve to open.
The flame should hit the thermocouple about 1/2 inch from the end. The flame can be adjusted, usually by a small screw on the gas valve. Refer to the owner’s manual for instructions for your specific heater.
Dip Tube Problems
The dip tube is a plastic tube that fits down inside the water heater inlet. It directs the cold incoming water from the water main to the bottom of the tank to keep it from mixing with the hot water leaving the heater.
If the dip tube breaks, the incoming cold water will mix with the hot as it leaves the heater and you will a much lower temperature hot water. Broken dip tubes usually result in symptoms like running out of hot water very quickly, or the water temperature is too low.
Leaking or dripping TP relief valve.
Storage water heaters have a safety device known as a temperature-pressure relief valve that opens if the temperature gets too high or if the water pressure gets too high. Without the TPR valve, also know as a pop-off valve, the water heater can become a bomb.
I just watched a youtube video by mythbusters showing a water heater blowing up… it was very impressive.
The owner’s manuals usually state that you should test your TP valve at least once a year by lifting the handle and releasing some water. In my experience, after you’ve done that there is a good chance it will drip forever.
The only solution I know of for a leaking TPR valve is to go down to the hardware store and buy a new one.
Thermostat problems
Thermostats rarely break down. If they do you might want to leave it to a professional to replace. Gas leaks can be extremely dangerous.
Symptoms that my present themselves when there is a problem with the gas valve are no hot water, or hot water that is too low in temperature. Most often the symptom will be no hot water which you will discover when you get in the shower in the morning.
Smelly hot water
If your hot water smells like rotten eggs, then there is probably bacteria which consumes the anti-corrosion anode rod and releases the gas that smells like rotten eggs. Usually it’s a magnesium rod. You can get Aluminum rods that the bacteria doesn’t eat, or use bleach to kill the bacteria, but it will probably come back.
The aluminum anode rod is probably the best solution. They are easy to replace. They thread down into an opening in the top of the heater that looks just like the inlet and outlets.
Strange noises
Gas water heaters can create some interesting sound effects. The main culprit is sediment buildup in the bottom of the tank. As the burners heat the bottom of the tank steam bubbles can form, and make popping and other sounds as they escape from under a layer of sediment. To solve this water heater problem you must flush the sediment out of the tank.
Milky whitish appearance
Air can get dissolved into the water, and when you fill a glass of hot water it appears milking in color. This is actually thousands of tiny bubbles. Let the water stand for a while and the bubbles will eventually all go away. It causes no harm, just looks odd.
Leaking water heater tank
This is my favorite way for a water heater to fail. When I see a puddle of water forming under the gas water heater in the garage, I know it’s time to call a plumber and have a new one installed. That way I don’t get inconvenienced for long.
The worst kind of failure is the one that gives you no warning. That’s just my opinion of course.
There is no way to fix a leaking water heater tank, it must be replaced.
I’m going to stick to tank type storage water heaters for this article because storage water heaters are much easier to trouble shoot and repair than tankless water heaters. They pretty much consist of a tank of water over a burner with a thermostat. They are pretty simple and very reliable.
Tankless water heaters are sophisticated high tech appliances. The tankless units have multiple sensors to monitor things like incoming water temperature, outlet temperature, exhaust temperature, and water flow all feeding information to an internal computer. The computer controls things like modulating gas valves and water flow valves. There are error codes and many models even have remote controls.
Typical problems you may encounter with your water heater are things like the pilot light going out or it won’t re-light, pressure relief valves that leak or drip, broken or damaged dip tubes, worn out anode rods, and leaking tanks.
Pilot light problems
Usually pilot light problems are a result of a bad thermocouple. The thermocouple sits directly in the flame from the pilot light and glows red from the heat. The thermocouple generates a small electric current from the heat and the current keeps the gas valve open.
If the thermocouple goes bad the pilot light will not stay lit. Replacing the thermocouple is relatively easy. Usually it’s held in place by a nut. It’s a small tubular shaped metal object with a small diameter metal tube which ends with a fitting that screws into the gas valve.
If the pilot light stays lit, but the burners won’t come one, check to see if the flame is bright blue. A weak yellow flame may not get the thermocouple hot enough for the gas valve to open.
The flame should hit the thermocouple about 1/2 inch from the end. The flame can be adjusted, usually by a small screw on the gas valve. Refer to the owner’s manual for instructions for your specific heater.
Dip Tube Problems
The dip tube is a plastic tube that fits down inside the water heater inlet. It directs the cold incoming water from the water main to the bottom of the tank to keep it from mixing with the hot water leaving the heater.
If the dip tube breaks, the incoming cold water will mix with the hot as it leaves the heater and you will a much lower temperature hot water. Broken dip tubes usually result in symptoms like running out of hot water very quickly, or the water temperature is too low.
Leaking or dripping TP relief valve.
Storage water heaters have a safety device known as a temperature-pressure relief valve that opens if the temperature gets too high or if the water pressure gets too high. Without the TPR valve, also know as a pop-off valve, the water heater can become a bomb.
I just watched a youtube video by mythbusters showing a water heater blowing up… it was very impressive.
The owner’s manuals usually state that you should test your TP valve at least once a year by lifting the handle and releasing some water. In my experience, after you’ve done that there is a good chance it will drip forever.
The only solution I know of for a leaking TPR valve is to go down to the hardware store and buy a new one.
Thermostat problems
Thermostats rarely break down. If they do you might want to leave it to a professional to replace. Gas leaks can be extremely dangerous.
Symptoms that my present themselves when there is a problem with the gas valve are no hot water, or hot water that is too low in temperature. Most often the symptom will be no hot water which you will discover when you get in the shower in the morning.
Smelly hot water
If your hot water smells like rotten eggs, then there is probably bacteria which consumes the anti-corrosion anode rod and releases the gas that smells like rotten eggs. Usually it’s a magnesium rod. You can get Aluminum rods that the bacteria doesn’t eat, or use bleach to kill the bacteria, but it will probably come back.
The aluminum anode rod is probably the best solution. They are easy to replace. They thread down into an opening in the top of the heater that looks just like the inlet and outlets.
Strange noises
Gas water heaters can create some interesting sound effects. The main culprit is sediment buildup in the bottom of the tank. As the burners heat the bottom of the tank steam bubbles can form, and make popping and other sounds as they escape from under a layer of sediment. To solve this water heater problem you must flush the sediment out of the tank.
Milky whitish appearance
Air can get dissolved into the water, and when you fill a glass of hot water it appears milking in color. This is actually thousands of tiny bubbles. Let the water stand for a while and the bubbles will eventually all go away. It causes no harm, just looks odd.
Leaking water heater tank
This is my favorite way for a water heater to fail. When I see a puddle of water forming under the gas water heater in the garage, I know it’s time to call a plumber and have a new one installed. That way I don’t get inconvenienced for long.
The worst kind of failure is the one that gives you no warning. That’s just my opinion of course.
There is no way to fix a leaking water heater tank, it must be replaced.
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