how to heat a boat cabin

How to Heat a Boat Cabin (Without Electricity)

How to heat a boat cabin and what’s the best heater to use in a boat cabin?

That question first got me thinking when I was on a boat trip on the Rhine river in Germany in the springtime and all the passengers shivered throughout the tour: There was no heater on the boat.

But why is heating a boat cabin important? By heating a boat, you not only feel more comfortable, but you also benefit some technical aspects of the boat: Heat protects the water and sewage system and the engine compartment from freezing.

People even say that you need to have a heater on board when you’re boating the Carribean sea. Weather is not always in your favor.

The best type of heater for a boat cabin

First, let’s check which requirements out perfect boat cabin heater needs.

If your boat is on a trailer during the wintertime, you might need to protect it from freezing: Some heaters have antifreeze protection which keeps the temperature just above the freezing point.

The antifreeze protection turns on the heater automatically when the temperature drops too low. Though, I think antifreeze is not mandatory, because most boats get away without any antifreeze measures.

A boat heater should always have tip-over protection, which means that it automatically turns off the heat when it falls over (which can happen on a boat).

Also, we’ll look out for heaters that don’t require electricity (I’ll explain why later on). The better choice is a gas heater because you can’t spill any fuel with it.

Preferably, your new boat cabin heater should be small and portable.

I prefer models that you can easily get everywhere. That’s why we’ll look out for normal types of heaters instead of specially designed boat heaters.

Basically, they’re the exact same product, but the boat heater companies have less competition, so they set higher prices while having a lower quality.

That’s why a normal type of heater is the better choice.

Electric Heaters or Gas Heaters in a boat cabin?

Should you rather use an electric space heater or a gas heater to heat a boat cabin?

Both of them have valid reasons for usage. Let’s take a look.

Electric space heaters are the better choice if you want to have lots of settings. They often have built-in timers, a thermostat and maybe even a built-in fan.

However, electric space heaters drain lots of energy from your boat’s power supply. When you also run a small fridge (or a similar device) in your boat cabin, you can easily overload the power supply and blow a fuse.

You could bypass using the power system of your boat by getting a generator. You can check out this article to find out which generator you can use to power a space heater.

However, if you don’t have a generator at hand already, it could be troublesome to install an electric space heater and a generator on your boat.

You could simply use another type of heater:

Gas heaters are efficient and don’t require any electricity.

“many owners, particularly those with smaller boats, speak highly of these types of [propane] cabin heaters.”

sailboat-cruising.com

In my opinion, gas is by far the easiest heating method for heating boat cabins.

All you need is a small gas tank and you’re set to start heating.

Which heater is the best for heating a boat?

The best heater to heat a boat cabin is also my favorite overall propane heater:

Generally, I recommend this model (the Big Buddy instead of the Little Buddy) because you get the same heat and efficiency on the lower settings, but you can also set the heat on “high” in case it gets uncomfortably cold on your boat.

The Little Buddy heater raises the temperature on your boat by about 10 degrees. Meanwhile, you can reach a temperature raise of 20 or more degrees with the Big Buddy.

To hook a 20lb propane tank to the heater, you’ll need this big buddy hose (amazon link). Without the hose, you can connect it to two 1lb propane cylinders.

A 20lb propane tank will last you about 24 hours on full heat and 65 hours on low heat. That’s up to one month’s supply if you heat your boat cabin on high heat in the evening hours only.

Carolyn Shearlock from theboatgallery.com said this about her Mr. Heater Little Buddy:

“No, it doesn’t turn the boat into a sauna . . . but it makes it comfortable to sit and read. And if I’m warm when I go to bed – and the sheets aren’t freezing – my body heat warms up the bed and I’m comfortable to fall asleep.”

Carolyn Shearlock – theboatgallery

The best thing about it is that you can get the propane tanks anywhere – even at Walmart.

You can get 30lb tanks for 40 dollars already – meaning that one hour of full power heating costs you 90 cents and one hour of lower power heating costs you about 41 cents

Things to remember while heating a boat cabin

Propane heaters are generally safe. A lot safer than electric heaters which could heat up your boat’s power supply.

But there are a few things to remember while heating a boat cabin with your propane heater.

Air regularly – Propane heaters (even though they are declared indoor safe) could increase the carbon monoxide levels in your boat cabin. So, make sure that you keep your cabin vented.

Also, heaters reduce the relative humidity in the air, which could leave you with a sore throat the next morning. So, just make sure you air your cabin regularly and get some humidity into your cabin.

3 Lessons from a boat heater accident

Here are 3 lessons learned from a boat fire that was caused by an electric space heater.

The couple that was on the boat that day didn’t get injured. Here’s what they said is important for keeping your boat safe:

Always have a fire extinguisher nearby – A fire extinguisher is a lifesaver. No explanation required.

Install smoke detectors – Smoke detectors alarm you in time. They are especially important if you have multiple compartments on your boat.

“Just like houses and apartments, boats need to have smoke detectors. […] It’s a good idea to have one in the engine compartment(s) as well as in living areas”

Heater placements – Place your heater in a safe spot on your boat and notice whether there are ignitable carpets nearby. Always think twice about running a space heater throughout the night. I’d even suggest avoiding running it overnight and spending some money on boat insulation (to retain heat longer).

Can you leave the boat heater on while you sleep?

Yes, you can leave the boat heater on while you sleep, but you should carefully make sure nothing can go wrong.

If you already know you want to leave your space heater on throughout the night, an electric space heater on low settings might be an even better choice than a propane heater, because electric heaters often have timer settings so they automatically turn off after some time.

But generally speaking, a gas heater on low heat is safe as well.

Most heaters you buy today are safe. Oftentimes they have overheat protection, a thermostat and tip-over protection (which is especially important on boats).

Conclusion

To heat a boat cabin, I recommend sticking to common propane heaters. They are versatile and you can also use them elsewhere: For example, if you don’t use your boat for a period of time, you can just grab your heater, and use it to heat your garage.

You can use them anywhere.

I believe it’s also important to insulate your boat’s cabin as much as you can. Insulation keeps the cold air out and makes sure that you don’t waste valuable energy on your boat.

Heating a boat cabin with air gaps will cost you a lot more in the long run than heating a boat with insulation.

I hope I could point you in the right direction with this article. If you want to learn more about heaters, check out the other guides on this site!

About the Author

Daniel Hirsch

Daniel is an electrical engineer, blogger, and author. He studied electrical engineering and information technology and decided to blog about heaters after working in the temperature sensing industry.