Common Hot Water Heater Problems

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Common Hot Water Heater Problems

Hot Water Not Working in House? Use This Guide of Common Hot Water Heater Problems to Find Out Why
 Common Hot Water Heater Problems - Shower Cold
When it comes to your home appliances, there is typically one in particular that you never want to experience issues with, and that’s your water heater. Not having hot water could be an extreme inconvenience in your life. You use it every single day and may even take some of it for granted. Hot water goes beyond comfort though, it is important for sanitation. When having hot water issues, it is important to address them quickly. A lot can go wrong with your water heater but 99% of the time it comes down to the most common hot water heater problems that we see over and over again.
Let’s take a look at some of the most common hot water heater problems for both electric and gas tanks.
Common Hot Water Heater Problems - Water Heater Diagram

Common Hot Water Heater Problems

Water Leaking at the Top

If water is leaking from the top of your heater, there are a few things that could cause the issue. The inlet valve on the heater might be leaking, the T&P valve could have failed, or the cold inlet or hot outlet pipes might have gotten loose.
  • Leaking Inlet Valve – This is where water comes into the tank. A leak here isn’t fatal to the tank and is often a simple replacement for a licensed plumber. The main water supply needs to be turned off for this repair.
  • Failed T&P Valve – T&P Valves release pressure that builds up in your tank. If this valve is leaking, it might just be letting off steam like it is supposed to. Continuous or prolonged leaking could also be a sign of high water pressure or the need for an expansion tank on your system. Many times though, these valves just fail. It is very important that your T&P valve stay in good working order though, so this needs to be replaced. Again, this is not a fatal repair for your water heater and is a simple repair for a licensed plumber.

Common Hot Water Heater Problems - top of heater

Water Leaking at the Bottom

Electric water tanks condensate and more often than not, that’s where the “leak” comes from. That’s one of the many reasons why water heaters should have a drip pan installed. However, there are some cases where it’s water flowing from the overflow pipe or the tank itself could be leaking. A leaking tank can’t be fixed. If you suspect that your tank needs to get replaced, it’s best that you can consult with a professional plumber. Plumbers have access to better quality water heaters than are available over-the-counter. A water heater should always be installed by a pro anyway. We recommend brands such as Bradford White, Rheem, and AO Smith.

  • Condensation – Nothing to worry about, really, but you might be losing some energy. A thermal blanket will help with thermal loss and a drip pan will protect your property.
  • Overflow Pipe – The overflow pipe is attached to your T&P valve. This is a trick, because the leak is actually at the top. See detailed description above for how to handle a failed T&P valve.
  • Leaking Tank – Corrosion can rust out the tank of your water heater. This is a fatal blow, unfortunately.

We wrote an entire article about this called Why Is My Water Heater Leaking from the Bottom? that goes into detail about how to repair each of these possible issues.

Common Hot Water Heater Problems - rusted out tank

No Hot Water or Lack of Hot Water

Electric water tanks are designed to heat water by using two heating elements. If you aren’t getting hot water at all, it could be a tripped circuit breaker, a bad heating element, or the thermostat.

For Electric Water Heater Units:

  • Circuit Breaker – if you aren’t getting any hot water, check your circuit breaker to make sure the water heater is getting power. If the breaker flips continuously you may need an electrician to look at your panel.
  • Bad Heating Element – Depending on the age of the water heater and whether or not it is one or both heating elements, this could be a repair or a replacement. Replacing both heating elements is nearly as expensive as a replacement, so it is rarely worth it. If the tank is older, the concern is that other parts of the heater will start to fail. Don’t throw good money after bad. An experienced plumber can help you make this judgement call.
  • Broken Thermostats – Thermostats often break along with heating elements. If both go out, a replacement is definitely more cost effective. There is an upper and a lower thermostat and one or both can break. Diagnosing, testing, and replacing these parts is a bit tricky and requires advanced knowledge of both plumbing and electrical, so it is best left to a professional.

For Gas Water Heater Units:

The most common reason behind having no hot water in the home is because of a lack of gas flow or a pilot light that’s turned off. Depending on the style of your gas water tank, check to make sure that the pilot light is on or that the breaker didn’t get switched.

On the other side of it, if you aren’t getting enough hot water, many things could cause this issue. It could be something as simple as needing to raise the thermostat on your tank during the winter months, due to thermal loss. If adjusting the thermostat doesn’t work, consult with a plumber because it could be a host of problems including; loose wiring, a bad element, a failing thermostat, poor insulation, or your plumbing system might benefit from a circulating pump.

Common Hot Water Heater Problems - temperature control

  • Raising the Temperature – Factory recommended settings for water heaters is 120°F. Setting your water heater higher than that may decrease the life of your tank, void warranties, or cause scalding. Please take this step seriously and be cautious. If you have young children, elderly people, or anyone with compromised reflexes it is important that you exercise extreme caution.
  • Loose Wiring – We recommend you have a plumber check the wiring. This might be a fire hazard.
  • Lower Heating Element – If one of the heating elements goes bad, the water may show up lukewarm. As opposed to when both break, it is possible that replacing the element will solve the problem at a minimal cost.
  • Failing Thermostat – Again, if just one of your thermostats are failing, there might be an opportunity for a repair. This will depend on the age of the heater and availability of parts.
  • Poor Insulation – Your water heater or hot water pipes may need insulating. This is an easy DIY job.
  • Circulating Pump – Sometimes house additions, new fixture demands, or poor designs can cause hot water problems in parts of your home. If one or two fixtures far away from your water heater aren’t getting hot enough water, the installation of one of these pumps will help. A circulating pump keeps hot water moving in a loop in your pipes, giving you hot water faster. A consultation with a licensed plumber will help you make a decision about the need for this product.

Common Hot Water Heater Problems - water from tap

Water is Too Hot

Having very hot water is just one of many common hot water heater problems that you might find with an electric heater. While the issue is most likely narrowed down to a problem with the thermostat or wiring, it could be as simple as a setting.

Common Hot Water Heater Problems - steaming water

This is a widespread occurrence during the transition period from winter to the warmer months. During the winter, your pipes get cold and require the extra heat to keep your water hot. Once the weather gets warmer, you can turn the thermostat back down.

  • Temperature Settings – Check the thermostat settings. The temperature should be set at 120°F – but not below. There are safety concerns with setting the thermostat lower, because it can breed Legionnaires Disease in your tank.
  • Bad Thermostat – Again, the thermostat could be failing. See descriptions above for more guidance on repair and replacement of this part.
  • Bad Wiring – Loose wiring can cause weak connections. Because this is a fire hazard, you’ll want to get a plumber to check on it immediately. Oddly enough, most electricians won’t look at water heaters. We don’t know why, so just call a plumber.

Low Water Pressure

Low water pressure is rarely a problem in Greenville, South Carolina. In fact, we usually see the opposite – high water pressure. The majority of times where low hot water pressure is an issue it is because the hot water tank is in an old home that has outdated plumbing. A licensed plumber needs to access plumbing replacements – this is not a DIY Job. Additionally, ailments such as calcium, sediment, and rust build-up in the tank can contribute to low water pressure in a water heater.

It is easy to reduce the amount of sediment in a hot water tank. Follow these easy steps to do this simple water heater maintenance:

  1. Turn off the water heater at the breaker.
  2. Close the water inlet valve at the top of the tank.
  3. Attach a garden hose to the drain valve at the bottom of the tank. (If you don’t have one, you can place a bucket under the valve. If the tank is located outside or in your garage, you could just let the water flow freely.)
  4. Open the drain valve. Let the water run until it is clear.
  5. Close the drain valve, detach the hose, and restart the water heater.

Dirty, Rusty, or Smelly Water

If you notice that your water is rusty or dirty, there’s a good chance that there’s corrosion happening in your tank and it should get looked at immediately. If you leave it untreated, the entire tank could fail and develop a leak or the heating elements can burn out.

Common Hot Water Heater Problems - rusty water

Smelly water, on the other hand, is likely a result of bacteria living in the tank. (If you use well water, you’re more susceptible to foul-smelling water. This may be unrelated/not dangerous.) If your hot water has a strange smell, start by flushing the tank using the steps above.

Hot Water Reheats Too Slowly

There are a handful of things that could cause your water to reheat slowly, but more often than not, the issue gets resolved by adjusting the temperature on your thermostat. If your water tank is too small for your family’s needs, there’s a good chance that your hot water is always going to reheat slowly, and you should look into bringing in a plumber to make sure that you have the proper size for your home and family.

For gas heaters, the burner orifice might need to get cleaned, or the gas pressure might be too low.

  • Undersized Water Heater – Most domestic water heaters are 30 or 40 gallon. Anything over 50 gallons requires the installation of a commercial heater and is special order. If you are getting into very high gallon storage, you should consider tankless. For an average family of four, a 40 gallon water heater is plenty but every situation is different!
  • Cleaning Burner Orifice – A very handy homeowner can try this on their own, but keep in mind it requires the disassembly of the pilot tube and is best done with sand paper and compressed air. If you aren’t comfortable handling the gas supply and pilot light elements of your heater, this is best left to the pros.
  • Low Gas Pressure – Call your gas company to find out how to check the pressure on your gas line. This is a critical step because low gas pressure may the sign of a leak somewhere on your line, an obvious danger.

Unique Gas Water Tank Problems

Common hot water heater problems overlap for gas and electric, but there are a few differences in how these water heaters work that are worth noting.

Pilot Light is Out

There’s going to come a time where your pilot light is out, and it’s a big time (and money) saver to know how to reignite it quickly, and safely. Use these quick tips to help you reignite your pilot light, and remember to reach out to a professional plumber if you need help or if you don’t feel comfortable doing it on your own.

Common Hot Water Heater Problems - pilot light

  1. Turn the temperature control to the very lowest setting, but not off.
  2. Turn the ON/OFF switch to PILOT.
  3. Remove the outer access panel to access the pilot igniter button (new models only).
  4. Press the pilot button along with the igniter button, and you should see a generated spark.

Pilot Won’t Stay Lit

This is one of the common hot water heater problems that give most people a headache because it can get very annoying. If your pilot light isn’t staying lit, thermocouple replacement might be required, or you could have a clogged vent or a bad gas valve. All of these are issues that you want to talk to a licensed plumber about. Don’t play with gas!

Common Hot Water Heater Problems - don't touch gas

  • Thermocouple Replacement – A few bolts hold the thermocouple in place, but the supply gas tubes for the heater are also attached. This is the part that scares most homeowners off. If you aren’t comfortable handling the gas supply elements on your heater, we recommend you contact a professional plumber.
  • Clogged Vent – This can be a dangerous and unhealthy issue, so you’ll want to handle it quickly. There are different types of vents – direct and power. Power vents use more energy and are a point of failure. Beware, these are more expensive to repair and replace.
  • Bad Gas Valve – A gas valve is the supply for your gas water heater. Again, because this involves the gas supply to your water heater we recommend that you get in touch with a professional plumber.

Regardless of if you have an electric water heating tank or a gas water heating tank, you can reach out to us with any questions that you have. All Clear Plumbing can provide you with knowledgeable and professional information to guide you in a trusted direction that fixes your common hot water heater problems quickly and efficiently. Just give us a call at 864-979-7059 or contact us.

Article Author: Anja Smith

Managing Partner

Anja Smith is the author behind the All Clear Plumbing blog. She also writes regularly for Plumber Magazine,, and on Medium