How Long Do Electric Oil-Filled Heaters Stay Hot? (Tested)

I took some simple steps to test how long an oil-filled electric heater stays hot.

As I have several in my house, I put them in different rooms and let them reach maximum heat before I turned them off.

Then I spent up to an hour monitoring how hot the heater stayed at the top and the bottom of the appliance. The different parts actually cooled at different rates.

Let’s start with a summary of the results, before getting into the details and a money-saving tip.

How Long Does An Oil-Filled Electric Heater Stay Hot?

On average, it takes thirty minutes for an oil-filled electric heater (1500W) to cool to the point that it is no longer warming the surroundings.

It takes forty minutes for the entire metal casing to be cold to touch.

How Long Does An Oil Filled Electric Heater Stay Hot

You may be wondering if I tested the appliances in a hot or cold climate and whether that makes a difference. The test was conducted in a mild climate when the outside temperature was 52 °F or 11 Celsius.

The house is well-insulated, and the rooms are the typical size of a modern suburban housing estate.

How The Heat Reduces Over Time

How The Heat Reduces Over Time

A typical oil-filled electric heater is about two feet high with long fins. Here is one of mine that keeps people nice and warm on the couch beside it!

They are dust magnets, so I cleaned this one up a bit for the shot!

But I wanted to point out that the top of the fins cooled at a significantly slower rate than the casing at the bottom. Let’s get into the details.

Time After Turning Unit OffTop Of ApplianceBottom Of Appliance
10 minutestoo hot to touchtoo hot to touch
15 minutestoo hot to touchwarm to touch
20 minutesuncomfortable to touchslightly warm to touch
30 minutesslightly warmroom temperature
40 minutesmetal is cold to touchmetal is cold to touch

How I tested the heat

I could have used a thermometer, but I think that the “feel from touch” description is easier for people to understand.

I was literally placing the palm of my hand against the metal casing at the top and bottom of the unit.

This also gives you an idea of when the heat from the appliance doesn’t represent a problem for a child or pet. After twenty minutes, the top of the appliance would evoke an “ouch” if a small hand touched it. At thirty minutes, it’s just a little warm.

These appliances present more of a problem for a small person pulling them over as opposed to the heat from a cooling unit.

How does this apply to heating a room?

For people sitting on a sofa near a heater, how long do they get the benefit of heat after you’ve turned the appliance off?

Typically, the warmth keeps radiating from the top of the unit for about fifteen minutes.

Half an hour after turning the unit off, there will be no benefit of heat in the near surroundings. The top is still slightly warm but you’re not going to feel any heat unless you are right beside the unit.

By forty minutes, the metal casing is colder to touch than the air in the room. The top of the appliance has also cooled completely at this time.

How To Save Money With These Findings

What all this means is that you can turn off the heater when you’ll be leaving the room in about fifteen minutes.

How To Save Money With These Findings

You will save a bit of electricity and make the appliance a little more cost-effective.

Dean Casey
About Dean Casey

Hi, I'm Dean Casey, the founder and chief editor of

With over 15 years of experience in the HVAC industry, my passion is helping homeowners achieve optimal comfort and energy efficiency in their living spaces. As a certified HVAC technician and consultant, I have developed a deep understanding of home heating systems, insulation, and energy-saving practices.

I started this blog to provide well-researched, practical advice to homeowners looking to improve their home's heating performance and reduce energy bills. Whether it's comprehensive guides, hands-on product reviews, or expert tips, my goal is to share valuable information with you, my readers.

I enjoy spending time with my family and exploring the great outdoors when I'm not busy writing and researching. I'm also an avid DIYer, always eager to tackle new home improvement projects and share my experiences with you.

If you have any questions or comments about home heating, please don't hesitate to reach out through the contact page on the website. I'm always happy to help!

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