If you feel uncomfortable with the fix, for your safety, hire a professional.
The surprise shock of a cold shower brings joy to a very (very) small sliver of the population. Voices will echo through the house: “Who’s using up all the hot water?”, ‘Where did my hot water go?”, “Somebody fix the hot water!”

Good news – that somebody could be you! If you can, first, identify your problem, then narrow in on its cause, a solution is within your grasp.
Note: If repairing your hot water heater yourself, always remember to turn off the gas first.

Identifying the Cause and Solution for Common Hot Water Heater Problems

Unfortunately, propane water heaters aren’t very cut-and-dry (and not just because they hold water!). There can be several causes to the same problem.

Problem: No Hot Water

Taking cold showers or doing dishes in frigid water can disrupt your daily life. Here are some likely causes that may lead you closer to a solution.

Possible Cause: Pilot Light Was Snuffed Out

The pilot light ignites the burner. So, if the pilot goes out or will not stay lit, your once hot water will quickly take a sharp turn towards icicles and glaciers. Okay, maybe not that cold, but you get the picture.

Solution: Relight the Pilot!

It’s as simple as it sounds. Depending on your heater, you will either use a match or built-in ignitor.

Instructions printed on the outside of your heater will guide you. Warning: The instructions call upon your complete patience. You will have to wait for specific amounts of time for your safety.

For pilot ignitor and manual lighter specifics, follow these links.

Possible Cause: Thermocouple Malfunction

The thermocouple is a safety device that senses when the pilot light is on.

You can think of a thermocouple like a traffic light. It gives the “green light” for the gas valve to release gas to the burner.

However, the thermocouple might incorrectly signal that the pilot light is out, prohibiting gas from flowing to the burner. No gas to the burner means no hot water for the house.

Solution: Replace Thermocouple

Luckily you won’t have to drain the tank to replace this part, but the difficulty of the project totters on the edge of doing it yourself and hiring a professional. Rely on your own comfort.

To replace the thermocouple, you should remove the gas manifold assembly and shut down the hot water tank.


Problem: Water Not Hot Enough

You’re running a bath (because you need to treat yourself) when the steady stream suddenly turns cold with no warning. Now, the bath water isn’t hot, isn’t cold. It’s just…lukewarm.

Lukewarm. It’s practically synonymous with dissatisfaction! If you’re dissatisfied with the temperature of your water, the root of your problem may be one of the following:

Possible Cause: Thermostat Troubles

The thermostat is typically built into the gas valve, and cannot be replaced without replacing the entire gas valve.

While replacing the valve is a viable option, you should first consider other factors that may contribute to your temperature issues.

Solution #1: Adjust Your Temperature Settings

Check your temperature settings. Appropriate settings should be detailed in the owner’s manual, but a common standard is 120 degrees.

However, it’s important to keep in mind the danger of increasing your water temperature. Your risk of burns increases with each ten degrees that you go above the standard temperature.

Solution #2: Check Tank Size Adequacy

Obviously, the bigger the tank is, the more hot water you will have. A smaller tank may not be producing enough hot water for you. When you run out, the hot water mixes with cold, creating that lukewarm temperature we discussed earlier.

If you have five or more people using water in your house, we suggest your tank hold more than 50 gallons to heat up enough water to your family’s satisfaction.

By purchasing a larger tank, your water will stay hot through more showers, baths, dish washings, dinner preparations, etc.

Possible Cause: Water Heater Vent in Need of Repair

Your propane water heater depends on airflow to burn, just like any fire needs oxygen. If there is a lack of air flowing to the burner, it will not heat the water as efficiently.

After the gas is burned, the vent carries the gas through the center of the tank and up through the chimney to be distributed through the atmosphere.

Now, sometimes this gaseous journey can be disrupted by a misdirected draft, an obstruction in the vent, or a blocked chimney flue.

Clogged vents are also highly dangerous due to the carbon monoxide that cannot escape if the vent is restricted.

Most propane water heaters have carbon monoxide detectors that will shut off the burner if the fatal gas is detected. So, if you don’t have enough hot water, make sure the problem isn’t toxic ontop of being dissatisfying.

Solution: Check Your the Vent Draft

First, check your vent draft.

You can do this by holding a match or lighter near the fume hood, which should be elevated on top of the tank by vertical legs. The water heater should have been running for several minutes before testing.

If the flame draws upward and doesn’t sputter out, the air is flowing in the correct direction – moving the gases up towards the chimney flue.

You should never feel the fume hood pushing air out; this is called a downdraft. It might sound kind of fun for watersports enthusiasts, but a downdraft signals something is wrong.

You can also looks for soot around the fittings because that’s a sign that the smoke isn’t making it up through and out of the chimney.

Okay, that was more of a solution to your doubt. But, now that you’ve identified a poor draft, the following solutions will work for blocked vents or chimneys.

Solution: Clear Blocked Vents

Propane water heaters will have a three or four inch pipe called a flue pipe that connects to the chimney. This pipe is only held together with screws, so it should be fairly easy to remove a section of the pipe and check for blockages.

Make sure the water heater is turned off before removing sections of piping.

If you find a blockage, you can use a piece of stiff wire to remove it, then screw the section of pipe back in, and wah-lah! You’re golden.

If you didn’t find a blockage, your problem may be located in the chimney.

Solution: Clear Out Chimney of Water Heater

If you have a masonry chimney, you should be able to see some light coming in at the top of the chimney, or you can use a mirror to look through for obstructions.

Once you identify the blockage, you can either climb up on the roof yourself or hire a chimney service. If you choose to be daring, you will use a set of rods and brushes and run them through the chimney to break the obstruction loose.

If you have a double wall pipe for a chimney, you should be able to unscrew the fittings to look up the chimney. Again, you should look for sunlight or use a flashlight to identify the problem.

If the obstruction is within reach you can use a stiff wire like in the vent, but otherwise, you should call a service.

Possible Cause: Problematic Dip Tubes

These long plastic tubes inside your propane water heater force the cold water to the bottom of the tank, keeping the cold and hot water separate.

If the dip tubes fail, the hot and cold water will mix, and your water will be lukewarm.

If you experience other problems, such as: the pilot won’t light or stay lit, your water is too hot, or the main burner won’t stay lit, or you have slow recovery time, the above causes apply, as well.

Problem: Black or Rusty Coloring of Water

Babbling springs and purity – that’s what you would love to think of when you watch your water run from the faucet. When your water takes on a black or rusty color, that image is lost.

Why does this happen?

Probable Cause: Dissolving Anode Rods

Made from either magnesium or aluminum, these rods sacrifice themselves by reacting with the water and rusting before your steel tank does. When the rod disintegrates, the tank will begin to rust, affecting the color of the water.

Anode rods are expected to last five years before disintegrating.

Solution: Replace the old anode rod

After reviewing the different types of metal for anode rods, as well as different installation types, you should remove the old anode and install a new one.

Problem: Water Leaking from Your Hot Water Heater

Possible Cause: Pressure Relief Valve Leaks

While this won’t cause a Hollywood-type explosion, a leak in your pressure relief valve might result in a different kind of “explosion”: a burst of water!

This valve’s job is to release pressure when it becomes too high. Makes sense.

However, the pressure relief valve may malfunction and release the pressure too soon. If the valve relieves pressure before it meets the upper limit, hot water will spray from the tank.

Solution:

First, check the seating by blowing off some water and closing the valve again. If it stops leaking, you’re ready to go!

If that doesn’t work, you need to install a new valve.

Possible Cause: Drain Valve Leaks

At the bottom of the tank you can find the plastic drain valve that can easily leak after use. So, what do you do when that happens?

Solution #1:

Open the valve a bit. Then, shut if back off and tighten it. That could have fixed it! If not..

Solution #2:

If the leak is minor, go to the hardware store and cap it!

Solution #3:

If the spigot is leaking a lot or leaking where it connects to the tank, you should replace the valve.

Possible Cause: Pipes Leak

Inlet and outlet pipes are located at the top of the heater, providing for the incoming cold water and outgoing hot water. The pipes could leak at two places:

1. Unions – on each pipe, so the tank can be removed

Solution:

Unions can be tightened with two pipe wrenches

2. Nipples – where the pipe enters the tank

Solution #1:

Drain down the water in the pipes by opening a valve in a nearby sink, then loosen the unions. Tighten the nipple with a pipe wrench. If that doesn’t work…

Solution #2:

Take the nipple out, and clean up the threads. Add fresh Teflon tape or pipe dope. Retighten the nipple and the union before turning the water back on.

Possible Cause: Tank Leaks

But, what if you see water leaking from the base or at the bottom of the tank, and it doesn’t go away the next day like condensation?

Solution: It’s time to replace your tank.

Problem: Sediment in Propane Water Heater

Just like we know the syrup always settles out on the bottom of our chocolate milk, the water in our propane water heaters has its own kind of chocolate syrup: minerals.

These minerals settle out on the bottom of your tank, creating sediment. Or when it hardens, you may be familiar with the term sedimentary rock.

While this sediment may or may not be bad for you, it’s bad for your water heater.

For one, the sediment wastes space in your tank. For example, if it takes up 20% of a 75 gallon tank, the tank can only heat up 64 gallons.

Furthermore, sediment lowers the heating efficiency because the tank has to heat up the sediment before heating the water. This burdens your fuel and utility costs.

Solution: Flush Your Hot Water Tank – Do it Annually

If you’re familiar with backwashing a pool, this is a similar process. (We just wouldn’t advise swimming in the tank after flushing).

To begin, you hook up a hose to the drain valve and run the other end to a floor drain, or nearby sink or tub. Then, ensure that all connections are tight and nothing leaks when you open the valve.

The cold water inlet valve should be on to purify the tank with fresh water, and all hot water valves and faucets should be closed. Keep running water through the tank until the water is clear.