How Long Should a Hot Water Tank Take to Heat Up?

Waiting for hot water can feel like forever, but how long is too long? Knowing the normal heat-up time for your water heater can help you spot problems early. Find out what’s typical, what’s not, and what you can do to get your water running hot again.

What’s the normal heating time for a hot water tank?

The time it takes for a hot water tank to heat up depends on a few things, like the size of the tank and the type of water heater you have. Here’s a quick guide:

• Electric water heaters: About 1-2 hours for a full tank.
• Gas water heaters: Usually 30-40 minutes.
• Tankless water heaters: Almost instant, since they heat water on demand.
• Recovering after use: Most tanks need about 20-30 minutes to reheat water after a shower.

If your water heater takes much longer than these times, it could signal an issue.

What is too long?

If you’re waiting over 2 hours for an electric heater or more than an hour for a gas heater, something’s likely wrong. Here are some signs to watch for:

• Water never gets fully hot.
• Only lukewarm water comes out.
• The heater runs constantly.

These issues might mean your water heater needs maintenance—or replacement.

Why is my hot water taking so long to heat?

There are several possible reasons your hot water is slow to heat:

Sediment build-up

Over time, minerals settle at the bottom of your tank, reducing efficiency. Flushing your tank yearly can help.

Broken heating elements

In electric heaters, the heating elements may burn out and need replacing.

Thermostat problems

A faulty thermostat might prevent the tank from reaching the desired temperature.

Get a new smart thermostat installed today.

Undersized tank

If your household uses more water than the tank can handle, it may struggle to keep up.

Old age

Water heaters usually last 8–12 years. If yours is older, it may simply be time for an upgrade.

How to fix the problem

If your water heater isn’t performing, try these steps before calling a pro:

1. Check the thermostat

Make sure it’s set to the right temperature—usually 120°F (49°C).

2. Flush the tank

Sediment build-up can be flushed out by draining the tank. This is a good DIY project for handy homeowners.

3. Inspect heating elements

If you have an electric water heater, check the heating elements and replace them if needed.

4. Insulate the tank

Adding an insulating blanket can help maintain the heat.

5. Upgrade to a larger or tankless model

If your tank is too small, consider upgrading. Tankless water heaters are energy-efficient and never run out of hot water.

Start your tankless upgrade today.

When to call a professional

If you’ve tried these fixes and the water is still taking too long to heat, it’s time to call in the experts. A plumber can diagnose and repair deeper issues, like gas supply problems or severe sediment damage.

We can help! Book Water Heater Repair today.

Don’t wait around for hot water

Your hot water tank shouldn’t keep you waiting. If it takes too long to heat up, figure out what’s causing the delay. A quick fix might be all you need to enjoy hot showers again. If you need a new hot water tank, we can help with that too.

Got questions or need professional help? Reach out today—we'll got you back to warm and cozy in no time!