How To Heat A Sailboat

How To Heat A Sailboat | Life of Sailing

Last Updated by

Daniel Wade

June 15, 2022

If you want to extend your boating season into the winter season, stay toasty warm, and dispel the dampness that can infiltrate your boat in cold weather, you need to get a reliable boat cabin heater.

Winter sailing is always a real challenge for most sailors given that the weather conditions are more adverse and calls for more preparedness. Fortunately, several types of boat cabin heaters can transform winter sailing into a more pleasant experience by keeping the interior of the sailboat warm and cozy. So if you do not want winter to spell the end of your sailing season, you’ve come to the right place: here’s how to heat a sailboat.

As we’ve noted, there are several ways to warm your cabin during the winter season or on a cold night. From hydronic systems, heating stoves, engine heaters, forced-air systems to reverse-cycle air condition systems and electric heaters, there are a lot of options for every budget. Although these systems may work differently, the basic idea is the same. They all either use fuel or another energy system to create heat that’s spread throughout the boat.

Let’s explore the most common ways to keep your sailboat warm during the cold season. But before going into that, let’s highlight some critical details.


Table of contents

How to Choose an Appropriate Boat Cabin Heater

The thermal outputs of these heating systems are generally measured in British Thermal Units (BTUs). The more BTUs a system produces, the warmer it can make your boat cabin. You should, however, remember that more BTUs will increase your electrical or fuel demands. In addition to BTUs, choosing the right heating system for your boat will depend largely on how well your boat is insulated, the kind of boat you have, how much time you spend sailing in cold weather, where you’re planning to sail the boat, and how much you’re willing to spend.

A Word of Warning

The dangers of poorly installing a heating system on your boat can never be underrated. Keep in mind that most of these systems will keep your cabin warm by burning oxygen, which can potentially fill the cabin with the deadly carbon monoxide that can quickly leave victims unconscious and may lead to death. As such, safety should be a priority.

How to Heat a Sailboat

Hydronic Systems

These systems are based on the same principles as household hot water heating systems. It revolves around a heated fluid running through a tube to radiators or fan units that warm the air. These tubes should run throughout the sailboat but the fan units or radiators can be divided based on the number of zones that the boat has.

In most cases, a hydronic system is smaller than a water heater but can also be used as a portable water heater for the boat, especially if you need hot water onboard. It’s generally installed in the boat’s engine room and can use a coolant to disperse the heat. It can use the fuel coming from the vessel’s main fuel tank or a special fuel tank.

The main advantage of using a hydronic system is that there is no moisture in the boat as there are no cold spots. An appropriate hydronic system should have a maximum output of 25,000 BTUs per hour while using 6 amps of power or 0.22 gallons of fuel.

Heating Stoves

Although they’ve been used for centuries, heating stoves remain one of the most popular ways to heat a sailboat. They can burn kerosene, diesel, and propane or even use solid fuels such as charcoal or wood. Some heating stove systems use the direct draft system whereby fresh air is pumped through a fan while others use the natural draft system whereby air is naturally pumped through the combustion process.

Either way, a heating stove should be located in the saloon to radiate heat and circulate hot air. They should be equipped with a damper to help in controlling the airflow, as well as an exhaust pipe to withdraw the exhaust gases arising from the combustion.

Keep in mind that most heating stoves do not use electricity. Nonetheless, a heating stove with an output ranging between 7,000 and 9,700 BTUs should be ideal, especially if it consumes about one pound of propane in about 5.5 hours.

Engine Heat

This revolves around using the engine’s heated coolant fluid to transfer the warmth into your boat’s cabin. The coolant lines should be designed to run from the engine into the heat exchanger. There should also be a fan that blows the cabin air into the heat exchanger so that the air is heated. The hot air can then be piped out into the boat’s interior through several hoses.

Using this system is advantageous in the sense that it’s quiet and depends on the engine’s closed-circuit cooling system, so it doesn’t require radiators or additional water pipes. Unfortunately, this system only works when the engine is running and can be quite expensive in terms of the extra engine maintenance and the fuel consumed.

Forced-Air Systems

This is a simple method that revolves around a heater burning fuel to heat air. This hot air is then forced through ducts via a series of vents to the boat’s cabin. Forced-air heaters are typically situated in engine rooms and generally have exhaust pipes to discharge combusted fuel.

The system can be turned on either manually or through its thermostat so that air and fuel are drawn into the combustion chamber to ignite the fuel and air blend under a controlled flame. This heated air is then forced into the duct and spread throughout the boat’s cabin.

Electric Heaters

This can be a perfect option if you occasionally go out on the water during cold days. Electric heaters function much like normal home ACs and usually run on 12-volt power. They’re typically mounted inside the cabin and run on electricity generated from the boat’s batteries that heat the coils. A fan draws air over the coils where it’s heated before another fan blows it into the boat’s interior.

The main downside of this system is that it has to use electricity, which means that you cannot venture very far from the shores. This is because you’ll need to recharge the batteries now and then and this will run them down very quickly.

Reverse-Cycle Air-Conditioning Systems

This works in the same way as a normal household heat pump by running in the reverse cycle. They’re typically very expensive but can be a great way to extend your sailing in the winter, especially if you want to circumnavigate the globe.

Head South

Another good option of heating your sailboat is heading south to sunny places such as Florida during winter. In most cases, the south is a bit warmer than the north during winter and you can keep going until you find the hotter climes of the south.


Installing a heating system is a great way of making the cold nights and winter season more pleasant and attractive. There are, of course, several ways to ensure that your boat is heated and warm, especially if you do not want to put the boat into storage and get back to the normal life on dry land just because it’s winter!

So if you still want to make winter a perfect sailing season, keep your cabin cozy with the above-described heating systems.

How To Heat A Sailboat
Daniel Wade

Daniel Wade

I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing.

Read more articles

by this author

Home /

How To Heat A Sailboat

How To Heat A Sailboat
7 Best Places To Liveaboard A Sailboat >>Can You Live On A Sailboat Year Round? >>

Most Recent

Important Legal Info

Similar Posts

Popular Posts

Get The Best Sailing Content

Welcome aboard! Check your email...
Oops! Something went wrong while submitting the form. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies.

(866) 342-SAIL

© 2024 Life of Sailing
Address: 11816 Inwood Rd #3024 Dallas, TX 75244
DisclaimerPrivacy Policy