Best portable boat heaters to stay frost free and cosy

Fox Morgan shares some of their tried and tested choices of best portable boat heater to help keep your boat frost free and cosy. There's heaters and then there's the best portable boat heaters!

The best portable boat heaters have to fulfil a variety of requirements and come in different styles and formats according to application.

Do you want to leave your boat and sleep soundly at night knowing that a frostat is taking care of things, avoiding ice and frost damage to domestic pipework and your engine? Or do you want a cosy cabin to sit in while you enjoy your boat year round?

Combining portable heaters with a dehumidifier is the best way to keep mold and mildew at bay, whether you live on your boat, or close it up for winter.

There’s a lot of blown air heaters, radiators both solid and oil filled and tube heaters on the market, but how do you choose the best one for your circumstances? Well, I’ve had over 40 years on boats of all kinds in all kinds of climates. I’ve experienced the best and the worst of cold damp cabins and cosy dry cabins. We’re obviously aiming for the latter.

Here’s my tried and tested selection of some of the best heaters for over wintering your boat.

I’ve created two lists, the best portable boat heaters for those who want to avoid frost damage while their boat is laid up and the best portable boat heaters for those who use their boat year round.

I use this radiator on my boat and after trying a range of others, this is the one I’m currently favouring for general all round ambient heat. It takes a while to get going as it is oil filled, but once it is up to temperature, which can be pretty hot, too hot for me to touch, then the saloon of my Dehler 36 is warm and consistently cosy.

It has three power settings with a 2kw top power setting and 800w Low setting with 1200w mid power setting. I combine this with my dehumidifier for a complete heating and drying solution. You can read about the dehumidifier here

I often find myself straddling this radiator to “warm my cockles” so to speak as it is just a perfect size for hugging.

When it gets really cold I find myself hugging this radiator

It’s also really good for drying out wet gear if hung overhead. The safety instructions say not to put anything over it and cover it, but I’ve managed to dry out a freshly laundered dog bed, hats, gloves and all sorts of small items on it.

I’ve even defrosted my cooking oil because the fins are just the right size to balance a bottle of cooking oil on them. Obviously you do this at your own risk.

Reasons to Buy

heats up a saloon comfortably, range of power settings, great for drying wet clothes

Reasons to Avoid

requires quite a bit of floor space, not as easy to stow as a smaller heater, takes a while to get warm

Rating 5/5

Buy it now

Buy it now from Amazon

As a 2,000 Watt convector radiator, the PureMate portable electric boat heater provides a high output should it be needed. For those needing less power the unit has four settings, the lowest of which reduces the output to 667 Watts.

There’s also a 24-hour timer, an adjustable thermostat dial, temperature control and an ECO mode for added control. Supplied with a remote controller and featuring a thermal safety cut-out, the PureMate is an oil-free radiator.

Designed to look good as well as being versatile, the unit features a sleek design and measures 55.3 x 25.5 x 64.5 cm.

Reasons to Buy

built in timer, remote control, instant heat from convector heating

Reasons to Avoid

convector heaters don’t retain heat, quite a bulky unit so hard to store, needs a fair bit of floor space

Rating 4/5

Buy it now from Ebay

Neatly packaged in a compact, if somewhat bulbous design, measuring just 44.6 x 29.6 x 19.4 cm, the Dimplex OFRB7N is a high performance, free-standing, mini radiator delivering 700 Watts of heating power.

Weighing in at just 5.4 kg, the unit can be easily moved around if required. As a state-of-the-art product, the Eco Chico uses Dimplex’s patented oil-free technology, which in addition to giving what Dimplex describes as an ultra-rapid heat-up time, is eco-friendly compared to its oil-filled counterparts.

This attractive little radiator is also BEAB (British Electrotechnical Approvals Board) approved and comes complete with a three-year manufacturer’s warranty.

I have used this heater for about 8 years now and I can happily leave it running in a closed cabin to warm it up. It is a low powered heater so it is best used in smaller spaces, such as the heads, or a closed cabin. The heat is somewhat lost in a saloon of a 36 foot sail boat.

I find this heater conveniently slots between the bottom bars of a clothes airer and it makes a good clothes drying heater when I sling my clothes over the airer like a tent. It makes a good home office heater to sit close to without risk of burning clothes/skin.

Reasons to buy

low power, no oil so no risk of piercing/leak, great for small spaces/clothes drying

Reasons to avoid

struggles to heat a saloon on a cold day, very basic

Rating 4/5

Buy it now from Aircon centre

As a budget priced electric radiator, the 800 Watt Daewoo Mini offers good power and excellent value for money. While this radiator is oil-filled, the unit does incorporate an automatic tip-over switch – which is obviously a key point to note for any product being used in a marine environment.

There’s also a thermal safety cut-out to protect against overheating and an integrated rotary thermostat which is fully adjustable. The lightweight 3 kg design measures just 38 x 28 x 14 cm, making the product convenient to use and easily transportable.

I use one of these in small spaces, such as my aft cabin or my heads area. It takes up very little space on the floor and the handy thing with this is that you can position it under where your towel or cold water swim kit hangs for example for a localised drying solution.

Reasons to buy

Doesn’t take up much room, low energy consumption, can be left unattended, fits in spaces where clothes can be hung to dry

Reasons to Avoid

Not powerful enough for a large cabin, no built in timer/basic functions

Rating 3.5/5

Buy it now from Ebay

This is a cracking little heater that has the option to oscillate to move the heat around your cabin. The digital readout allows you to fairly accurately set your thermostat for desired room temperature and then you can set it running. It is relatively quiet as fan heaters go and I have this one running in all sorts of cold places I want to heat up quickly.

I find myself standing in front of it warming my hands and find it convenient to move it from desk top to floor and back to table top. The readout is easy to see in the dark and the auto power adjust is handy for being a little bit more economical with the electricity it requires. With the auto cut off if it falls over you can sleep soundly at night leaving this on.

the top has a moulded handle built in

the air filter is useful to avoid dust particles going into the fan element

The fan part is one of the quietest fan heaters I’ve used but it isn’t silent so some people might find it annoying. I love this little heater for the combined portability and the amount of heat it kicks out. Combine this with a larger oil filled radiator and this is my current set up for a cosy winter cabin.

Reasons to buy

Powerful heating from a small unit, fills a cabin with heat very quickly, good thermostat settings

Reasons to avoid

Not everyone likes the sound of a fan running despite this being one of the quietest available

Rating 5/5

Buy now from Argos

Buy now from Amazon

This fan heater has been around for quite a few years now. It’s a powerful unit at 3kw so if you have the power cable that can handle it, then this is just the job to stick on when you arrive at a cold boat and want to warm it up quickly.

It will heat up a moderate sized boat saloon area in about 15 minutes and gives that instant burst of heat. You wouldn’t want to use this as the sole mode of heating though as it is quite noisy and does require some power to run. It’s also great to heat up a shed or workspace quickly.

TOP TIP: if you are using one of these, then an issue I’ve had with most of the kick space heaters is that it can be hard to see where the dial is pointing to. I got around this with some red PVC insulation tape and put on some of my preferred settings to make it easier to see at a glance, even in the dark with a head torch.

BEWARE: a 3kw heater can really push some extension cables beyond their limit. Be careful with the loads you place on 13A plugs and their cables.

I added some red insulating tape to help me see where to click the knobs round to for the best heat settings.

Reasons to buy

Powerful heater fills a room quickly, easy to stow when not in use, easy to position.

Reasons to Avoid

Noisy, some boat electrical systems might struggle with a 3kw heater

Rating 3.5/5

Buy it now from onbuy

The smallest of the best portable boat heaters covered here is also unsurprisingly the least powerful, for the Dimplex ECOT1FT tube heater delivers just 40 Watts of warmth. It’s also an unashamedly basic product with no programmable features or timer functions.

But what this little boat heater is good at is delivering is a low amount of heat continuously. All of these attributes, or lack of them, is what make this little tube heater an ideal tool for small spaces.

Essentially, it’s a fit and forget product that will take the edge off the chill and help protect from cold and frost throughout the winter season.

This tube is ideal for cupboards and closed lockers where you require frost protection and the continuous heat will help to keep condensation and humidity at bay too. Ideal for a lifejacket hanging storage or other cupboard with moisture or heat sensitive items inside.

I use one of these inside my wardrobe and it keeps my clothes feeling fresh and damp free.

Reasons to Buy

Versatile and can be mounted almost anywhere, low power, safe to leave running, low power consumption

Reasons to Avoid

Not suitable as a cabin heater

Rating 5/5

Buy it now from Screwfix

Designed to be left running continuously, the Dimplex ECOT2FT is a compact tubular boat heater measuring just 71.3 x 8.1 cm. The unit’s low power 80 Watts rating means that it perhaps best described as a trickle heater; it won’t keep your boat warm but it will provide sufficient output to ward off the chill.

Popular amongst the owners of smaller vessels, boat heaters such as the Dimplex ECO2FT are noted for their durability, dependability and economy.

Their reliability is doubtlessly enhanced by the fact that there is very little to go wrong – for inside the tubular metal casing there is just the heating element, a thermostatic control and precious little else.

Ideal for situating in an engine compartment or room.

Reason to Buy

Reliable constant low level heat in a confined space, safe to leave running unattended, low power consumption

Reasons to Avoid

might be a little too long for some cupboard spaces, this is not a cabin heater

Rating 4.5/5

Buy it now from Screwfix

Buy it now from Amazon

One of the most respected names in the heating world, Dimplex’s heavy duty Cold Watcher 500 boat heater is compact and robust and can be depended upon to provide protection against the cold and frost.

The unit’s 500 Watt element is controlled by a rotary switching thermostat. It’s a no frills basic heater and measures just 25.5 x 33 x 15 cm. On frost setting the heater clicks on at around 7 degrees C to maintain a safe temperature for boat systems, pipe work and other temperature sensitive items onboard.

For added protection, the unit has a water resistance rating of IPX4 and has been tested against the British Standard for frost protection.

You’ll find this heater on lots of boats, inside caravans and in all sorts of places that need a gentle continuous heat and can be left to just get on with the job of keeping the frost at bay.

It’s not just one of the bets portable boat heaters, but it has universal appeal for lofts, greenhouses, sheds and so on.

If you want a cosy warm cabin because you are staying onboard though, you might consider one of the other heaters further down this guide.

Reasons to Buy

No frills means very little to go wrong, it can be wall mounted, can be left unattended

Reasons to Avoid

Not intended for use as a main heater

Rating 4/5

Buy it now from Amazon

Available from Force 4 Chandlery, Amazon and a load of other retail outlets online, the Stor-Dry is a low wattage warm air circulator designed to combat mould, mildew and musty odours.

The unit draws less than 75 Watts and is rust and corrosion proof. As a dual action air dryer, the Stor-Dry features both a heating element and a fan in a single unit. With no reservoir to empty, the unit can be left running continuously.

It works in a similar way to a tube heater so there’s a basic element radiating heat, but where this heater differs is that it has a fan that gently circulates air, pulling it in through the bottom of the unit and expelling slightly warmed air through the top vent.

This is another heater that can be “set and forget” as you can safely leave this running without being in constant attendance. You can leave two or three of these running in different cabins throughout your boat and it will keep the air moving and the frost at bay as well as being useful to reduce the risk of mould and mildew growing.

Reasons to Buy

reliable set and forget, low energy consumption, can be powered from solar/wind due to low power use

Reasons to Avoid

Not a cheap option to buy initially, might be hard to position on smaller boats

Rating 4.5/5

But it now from Amazon