Hot Water Tanks 101 - Everything You Need to Know

Winter is coming, and one of the most important things to do in preparation for it is to make sure your hot water tank is working well. No one wants to get stuck in the middle of winter with no hot water. Hot water tanks need some annual maintenance, and this is the time to do it.

Knowing a little about how hot water tanks work and some of their common problems can help you keep yours in good running order. It’s also a good idea to know when it’s time to replace your old water heater. Read on to learn a little more about hot water tanks and the most common questions people ask about them.

How a Hot Water Tank Works

There are two main types of storage tank water heaters: gas and electric. In a gas heater, a gas-powered flame at the bottom of the tank sends hot air up a chimney that runs through the middle of the heater. This chimney transmits heat to the water, and when you turn on the hot water tap, more cold water flows into the heater, displacing hot water up the hot water pipe.

Electric water heaters work the same way in terms of water displacement, but their heating method is different. Instead of a heated chimney warming up the water, electric heaters have heating elements that extend out into the water tank. Both styles of hot water heater also have a sacrificial anode that rusts faster than the material the hot water tank is made of, preventing rust from forming on the tank.

How Often Should You Replace a Hot Water Tank?

How often you need to replace your hot water tank depends on what type of tank you have. Electric hot water tanks last a little longer than gas ones, with a typical warranty time of 6-8 years depending on the manufacturer. Gas heaters will usually last for around a decade.

There are a few signs you can look for to see if your hot water tank needs replacing. If you start to notice leaks, you may be dealing with a very dangerous situation if you don’t get your tank replaced. You may also start to see rusty water in your pipes or hear knocking noises coming from the heater.

If Your Hot Water Tank Won’t Stay Lit

If your hot water tank won’t stay lit, one of the first things you should check is the thermocouple. The thermocouple is a device that checks if your water heater’s pilot light is on. If the thermocouple has been damaged, it may think the pilot light isn’t on and not light your water heater.

See if the thermocouple looks dirty or bent; if it’s bent away from the pilot light, try to bend it back towards that flame. You may also have a dirty pilot tube, so let the tube cool, and then try to remove any blockages with a needle. If none of these work, it may be time to replace the thermocouple entirely.

If Your Hot Water Tank Isn’t Filling Up

If you notice your hot water runs out very quickly or you have low hot water pressure, you may have a problem with your hot water tank not filling all the way up. As we mentioned, when you turn on the hot water tap, cold water flows into the bottom of the tank, displacing the hot water and forcing it out of the tap. A drop in hot water pressure may mean that cold water is just filling up the empty space instead of sending hot water up the pipe.

The first thing to check if your hot water tank isn’t filling all the way up is if you have a leak. If there doesn’t seem to be water leaking from anywhere, try holding open the temperature-pressure release valve. You may have a pressure lock, and letting that pressure will allow your tank to fill back up.

If Your Hot Water Tank Is Leaking from the Bottom

If you notice water leaking out the bottom of your hot water tank, there are a few things that could be the culprit. Your drain valve, the opening that allows you to drain your water tank for routine maintenance, may be leaking. If it is, this is not a serious problem and can be fixed.

You may also be seeing water from normal condensation on the water heater. If this is the case, the easiest thing to do is turn the thermostat up. Water could be leaking out from around the pipe connections, in which case a few turns of the wrench will fix it!

If Your Hot Water Tank Is Leaking from the Top

If you discover your hot water tank is leaking from the top, the first place to check is the pipes that go in around the top. Your hot water tank is a pressurized system, so loose fittings around those pipes at the top could create a leak. Dry the area off thoroughly, have someone turn on a hot water faucet upstairs, and see if beads of water start to form around those pipes.

If the pipe fittings aren’t leaking, the issue may be the temperature-pressure valve. The valve may be opening on its own to release pressure in the tank. This means there is a buildup of pressure in your tank, a dangerous situation that could lead to it exploding; call a professional for help

Learn More About Hot Water Tanks

Hot water tank maintenance and troubleshooting don’t have to be difficult. Routine checks on the sacrificial anode and annual cleaning can keep your hot water tank working well for years to come. If you notice problems arising, be sure to address them quickly; delays can lead to dangerous and expensive home repairs.

If you’d like to get help keeping your hot water tanks running, get in touch with us at Mr. Rooter. We’re a locally owned and operated plumbing company in Ottawa that offers commercial, residential, and emergency services. Request a job estimate for your maintenance or repair work today.