Heating your Narrowboat

Your narrowboat is very much like a house, except it is a mobile house. When you stop cruising for the day in winter or that not so balmy summers day, you will require some form of heating. If you stopped moving in winter at a marina, you will also require hot water. 

When you cruise along the waterways, and you have a calorifier fitted, linked up to the cooling system to your engine, then the calorifier will heat up your domestic hot. However if you are not running the engine this source of hot water is not available.


The Narrowboat stoves

Morso Squirrel Stove

Therefore you require other ways to obtain heat. The traditional way is to have a log / coal stove which warms up the inside of the boat. If installed with a back boiler for your hot water, you will also get domestic hot water.

These types of stoves are not cheap to buy in the first place and require regular cleaning. They do add a lovely warmth to the boat but can be quite dirty. They are sometimes referred to as due fuel stoves. There are many on the market, but the main type used is the Morso Squirrel 1410. This can kick out in the region of 4.5 KW.

The unit comes without a back boiler, but comes with the optional extra to fit at the rear of the stove. In addition you will need a Flue, which will need to go through the roof of the boat. 

There are Boat Safety requirements like distances and hearths to consider as well if fitting one. 

Once running the fire will provide you with a lot of heat which you control with the twist control vents.  Once out, the fire will need to have it’s ash can removed and emptied, which is very dirty.

The down side to this system is that it is inconvenient when the weather is mild just to run for hot water, and makes the boat hotter than you would like, if you are static. There is an upside in winter, that allows you to place say a kettle on the top to bring to the boil for a nice cup of tea. Some folks even cook stews and baked potatoes.


Diesel Heating

Specialist marine configured systems such as Webasto and Eberspacher are available for both wet (hydronic) and dry (blown air) installations and come in a range of outputs to suit craft from small cabin cruisers to the largest of wide beam boats.

webasto-termo-top-evo-4Some types of system can be fueled by either LPG or Diesel. However the LPG systems like ADLI heaters,  do seem to be much more expensive to run against the Diesel versions. The majority of installations on narrowboats on the inland waterways are fueled now by diesel for this reason. A forced air combustion system is commonly known as diesel central heating or referred to by their brand names, like Webasto or Eberspacher.

Webasto or Eberspacher are now the same firm and have marine versions of the heaters, like the Webasto Thermo Top Evo 4 Narrowboat marine heater. There are good suppliers like King Lock Chandlery who we do recommend. PLEASE NOTE The Thermo top range for cars looks the same but the ECU is designed for cars NOT marine use. You must have the correct version for a marine unit.

For example, a basic installation could be a warm air blower servicing a single duct for keeping a cabin warm. Try not to go this route as they produce a lost of dust, which in a small space like a narrowboat, is not ideal. The best and most common way is central heating and water heating for domestic use through a calorifier, supplying a number of radiators controlled via a multi event timer. You can also integrate these units with marine air conditioning system.


Electronic Control…

The use of electronic control units not only allows for simple diagnostics in the event of a fault but also enables remote heating control via smartphone applications for top of the range models, however these are very expensive and mostly require their own Simm card to communicate. You can however have a Heatmiser timer which allows similar timing control as a domestic system for narrowboats, these systems provide the closest marine alternative, to a familiar domestic heating system.


A Calorifier is cylindrical shaped tank, calorifiers are a useful way of recovering waste heat and transferring it into domestic water systems.  The calorifier is plumbed into the engine coolant re-circulation system and uses a series of coils inside the tank to heat a body of water contained in the main shell of the tank. This can be from any heat source.

It is very much like your standard central heating copper immersion heater in the airing cupboard, however can be mounted sideways or vertically.

Like its domestic cousin, the marine calorifier can also have a 230VAC immersion element as a back up and can be linked in to most narrowboat central heating systems such as diesel fired, forced air combustion and even the back boiler on a multi-fuel stove to make use of the excess energy these systems produce.

The Calorifier is commonly installed in the engine room. They come in a range of shapes and sizes, vertical or horizontal. Location becomes only a matter of efficiently connecting it to your boats services.

The sizes range from around 20 litres up to about 120 litres and often two calorifiers can be linked if required. The only restrictions in size and location being the power of the available energy to heat the water and the availability of water itself.

When you are deciding which size your calorifier should be on your narrowboat, you need to ensure you have an adequate electrical supply. Most calorifiers will come with a pre-installed 1kW immersion heater. We advise that this is only wired for use when only connected to a shoreline. They will run from an invertor but are very supply hungry.

Please note. Most calorifiers have copper internal coils for a balance of efficiency and cost. If you have a central heating with an aluminum heat exchanger or if there is aluminum any where in the system, you will need a calorifier with stainless coils. It’s that old favourite, galvanic corrosion and the interaction between two different metals in water. This will cause internal corrosion of the system unless all metal system components are matched  in accordance with the manufacturers installation instructions.