no hot water from bathroom sink tap

Why You Have No Hot Water

A hot, relaxing shower is calling your name after a long day at work. Instead of the familiar stream of hot water, an icy, unexpected blast of cold water hits you in the face. Unpleasant doesn’t begin to describe it. Hot water is one of those things we take for granted. Your hot water system is probably the most underrated appliance in your home and doesn’t get a second thought. At least until you have no hot water.

There’s a whole host of different reasons why your hot water heater might not be working properly. With over 25 years in the plumbing industry, we’re here to break down all the common hot water system problems and even show how you can fix them yourself in many cases.

Electric Hot Water Heater Problems

Have you got yourself a storage-based electric hot water system? Here are the common problems we encounter when it comes to this type of water heater.

Faulty Heating Element

One of the most common causes of no hot water in electric water heaters is faulty heating elements. This is the part of the system that does the heating in your hot water tank.

Thankfully, a licensed plumber can replace heating elements. If the heating element is faulty, however, it’s likely time for a whole system upgrade.

Faulty Thermostat

The thermostat controls the temperature of your hot water. Electric water heaters tend to have two thermostats – one at the bottom that controls the bottom heating element and one at the top that controls the bottom and top heating elements.

When the bottom thermostat is broken, you’ll typically find that your water isn’t hot enough. If the top one, however, is faulty, this is where you’ll more likely encounter no hot water at all.

Depending on the fault, you might be able to repair or replace a malfunctioning thermostat.

Tripping High-Temperature Cut-Off Switch

Your electric water heater has a high-temperature cut-off switch built into it that will turn off the heating elements if the temperature gets too hot. This one is easy to fix, your water heater will have a reset button you can simply click to get the water heating again.

Circuit Break Tripping

The cause of your no hot water might be a tripping circuit breaker. Your hot water system should have its own dedicated circuit, so identifying if this is the source of your unfortunate cold shower should be easy.

You’ll easily be able to identify this as the cause as the hot water system circuit breaker will be the only one out of line from the rest. You’ll need a professional plumber or electrician to resolve this kind of problem.

Common Problems With Gas Water Heaters

If you’ve got a natural gas water heater, then you have a whole separate list of problems to be concerned with.

No Gas Supply

The first and most obvious thing to check when your gas water heater isn’t heating water is if it has any gas. The gas line might have been inadvertently shut off, so check that the gas is on and the gas valve is not in the off position. If this is the case, you’ll need to open the valve again and relight the pilot light.

Pilot Light Is Out

If the gas supply isn’t the problem, the next likely culprit is that the pilot light is out. There are a few things you can check for if this is the case:

  • Thermocouple – An important safety device that shuts off the gas supply to the pilot light in case it goes off. It should be tightly connected to the gas line and free of any blockages.
  • Air in the gas line – air in the gas line can prevent the pilot light from staying lit. You can try to relight the pilot light several times to try and force any air in the line out.
  • A blockage in the pilot light orifice – this controls the flow of gas to the pilot and is very precise. Any kind of blockage can interfere with its operation. Thankfully, a plumber can clean or replace this relatively easily.
  • There is a blockage, bend or defect in the supply line – a gas supply line that isn’t perfectly intact can cause intermittent heating as well as pose a serious risk to your home with a potential gas leak. This needs to be remedied by a fully qualified gas fitter urgently.
  • You have a faulty gas control valve – critically important to the flow of gas to the pilot, this valve cannot be repaired and must be replaced by a licensed plumber.
  • Burner is dirty or clogged – a dirty or clogged burner can prevent ignition of the burner. This part of your gas hot water heater can be removed and cleaned.
  • Inadequate ventilation – the by-products of the pilot light are vented out from your gas water heater with a flue. Any obstructions in the flue can prevent ignition or the pilot light. Cleaning the flue is simple, but can be quite a dirty job and is best left to a professional plumber.

General Hot Water System Problems

Regardless of what type of hot water system you have, there are some common problems you can keep an eye out for.

Faulty Thermostat

If you have a correctly-set thermostat in your hot water system, but have no hot water to show for it, it’s time to call for a replacement. You will need a fully licensed plumber for this.

Burner Build Up

Sediment can build up on your water heater’s burner over time which can impact water pressure and its ability to heat water. You can replace the burner, but plumbers will typically recommend that you replace the whole unit if this component fails.

Leaking Tank

If your water heater tank has sprung a leak, there will be no water to heat in the first place. Unfortunately, you cannot repair leaks in storage tank water heaters, and you will need a whole system replacement.

Inadequate Tank Size

One major problem with all storage tank hot water systems is that there is only so much hot water they can store at a time. If you use all the hot water, you will need to wait for it to refill the tank and heat it again. In the meantime, it’ll leave you with no hot water.

Continuous Flow System Problems

If you have a continuous flow system, there are two common problems that might explain your ‘no hot water’ problem.

Low Flow Fixtures

The first is that your fixtures do not have a flow rate high enough that trigger your instant water heater to turn on.

Continuous flow systems do not heat water unless you turn a hot water tap on. The flow rate must be high enough that the system can sense that it is on. This can occasionally be a problem for homes with low-flow fixtures.

Exceed Unit Flow Rate

Alternatively, your home might be using too much hot water at once so that it exceeds the unit’s flow rate. This means the hot water will be spread too thin and could feel lukewarm or cold to the touch.

Whatever the problem, you’ll need a fully licensed plumber/gas fitter to get your hot water back. Metropolitan Plumbing has over 25 years of industry experience and can get your hot water flowing again today.

Don’t delay, contact us today and we can have a hot water plumber with you in just one hour*.


Published: 2022-04-12

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