If you’re running out of hot water faster than usual, or you’re trying to turn up the thermostat and hope for the best, then we have some bad news for you. It won’t help! But why does this happen in the first place?
Find out what’s causing itIt’s not you. Your water heater is either undersized, full of sediment, or nearing the end of its life, and fixing it doesn’t always solve the problem.
Before you can fix a hot water problem, you should know what kind of system you’re actually dealing with.
This is what most homeowners in Ontario have. A tank water heater (gas or electric) is quite large (ranging from 150 to 270 litres). It stores preheated water and releases it whenever you turn on a hot tap.
Tankless water heaters (gas or electric) work completely differently from the tank models. Instead of storing hot water, they heat water instantly as it flows through the unit. No tank means no waiting and no issues, such as hot water runs out after one shower. You get hot water on demand, every time you turn on a tap or shower.
Heat pump water heaters (standard or hybrid) don’t generate heat directly, like traditional units. Instead, they move heat from the surrounding air into the water, which makes them highly efficient under the right conditions.
Gas-powered tank heaters use either fan-assisted (power vent) or natural draft (direct vent) systems to safely exhaust combustion gases. They heat water faster than electric tanks, which is why many Ontario homes rely on them. But since this type uses gas, many homeowners face a gas leak smell near the water heater, which is really dangerous.
When your water heater can’t keep up, you wonder, “How do I know if my water heater needs replacing in Ontario?” Now that you know the systems, here’s a breakdown of what’s most likely causing your specific problem and what can actually fix it.
Reason #1
You ask yourself: “Why does my hot water run out so fast?” The answer is your tank, which is just too small for your needs. A hot water tank stores a set volume of preheated water, and when that’s gone, you’re waiting for cold water to heat up from scratch.
What you notice: Hot water runs out at the same point every morning or evening. You take two showers back to back and there’s not enough hot water, and by the third, it’s cold.
How to fix it: You can buy a larger tank, but it doesn’t solve the fundamental problem since a tank always has a limit. The permanent fix is going tankless.
A tankless system heats water on demand rather than storing it, meaning there’s no fixed supply to run out of, regardless of how many people are showering back to back.
Reason #2
Another reason why the water heater not getting hot enough anymore is Ontario’s hard water, causing sediment to build up in the system, obstructing it. You may not notice this until your hot water runs out much more quickly than before, and the shower gets cold halfway through.
The signs: It happens gradually, and you might not even notice it in the beginning. Then you hear rumbling or popping from the tank, and wonder what’s that? That’s the heating element burning through accumulated scale.
How to fix it: You may flush the tank, but if the water is hard, you’ll need to do it often to keep the system working. A permanent solution would be installing a tankless system. No tank means no sediment and annual flushings.
Reason #3
If your hot water used to last longer but now runs out faster, it sometimes means you’re using more hot water than your heater can keep up with.
The signs: You jump in for a shower right after someone else, and the water’s cold. Or you start the washer while someone’s showering and notice the water temperature drops significantly.
How to fix it: You could try coordinating everyone’s showers, laundry, and dishwashing, but let’s be honest, that’s nearly impossible in real life. If you’re constantly running out of hot water, consider a tankless system or a larger tank.
Reason #4
This part of your system is too important to ignore! It reads the water temperature in the tank and tells the heating element when to fire up and when to shut off. Unfortunately, DIY water heater repair won’t help here.
The signs: Water is warm but never fully hot, regardless of the thermostat setting. If you’ve turned the dial up more than once in the last year just to maintain the same performance, then the thermostat must be replaced.
How to fix it: Call in a plumber to test the thermostat with a multimeter. By the way, it’s not that expensive to replace it.
Reason #5
Searching for “cold shower after 10 minutes causes?” That’s the one. A broken heating element is one of the most common hot water problems in Ontario homes, especially if your water heater is 10 years old and you don’t get enough hot water.
The signs: Hot water runs out significantly faster than it used to, even though nothing has changed in your habits. If the element is faulty, the tank can only heat the water above it, leaving you with never enough hot water.
How to fix it: Plumbers usually replace faulty heating elements, and, as with a thermostat, it’s quite affordable to do so.
Constantly Running Out of Hot Water? Let’s Figure Out Why!
Tired of cold showers and adjusting your thermostat just to have enough hot water? Answer these 7 quick questions, and we’ll tell you exactly what’s likely going on and what to do about it.
It’s time to consider your replacement options. Here are some solutions that can ensure you always have the hot water you need.
Why place this as the first and most efficient option? Unlike tank systems, tankless water heaters deliver hot water on demand, so you never run out.
Did you know: A tankless water heater typically heats water in less than a minute, while a standard tank heater can take 20–40 minutes to recover between uses. That means you can shower basically endlessly.
Sometimes, sticking with your standard tank water heater is the simpler and more affordable solution. But just sometimes.
This option will definitely solve your problem, but not for long. Once you use more water, the issue will return, and you’ll have to replace the tank again.
Sometimes, you don’t want to replace your unit just yet, thinking that fixing the water heater leaking from the bottom, replacing thermostats, or flushing the tank means getting more hot water, at least for a while.
Most of the issues we talked about come down to an old or undersized water heater. Sure, you can flush the tank, replace a heating element, turn up the thermostat or even watch a YouTube water heater tutorial. It will help for a while.
If your system is under 8 years old and the issue is minor, a repair might make sense because no hot water at all doesn’t always mean an emergency. If your appliance is old, needs many repairs, or if you often have to balance showers and laundry, it’s time to consider a replacement.
Consult a plumber to check your home’s actual hot water needs and install a system that covers them, saving you money on energy bills and repair headaches.
