A post about solid fuel and diesel stove safety on boats.
Boat stove safety is an important issue for people living on the inland waterways. At Marine Heating Solutions, we work on boats nationwide. Lately, we have come across some boat stoves which were in shockingly bad condition. Many of these were posing a serious fire and carbon monoxide poisoning risk. This post is aimed to give you an initial idea of what is needed for your boat stove to be safe. We are following Boat Safety Scheme guidelines and best industry practices. Always seek professional advice, if you have any doubts at all.
So let’s look at some basics like the general condition of the stove, flues, hearths, distance from flammable or combustible materials, and ventilation.
Hearths are an important part of your boat stove installation and need to be constructed correctly with the right materials. Heating appliance manuals will normally specify what distances need to be kept from combustible materials. Soliftec – The Solid Fuel Technology Institute gives guidance on how to construct a safe hearth for your stove.
Generally speaking, the hearth should be made of fireproof materials. Underneath the stove, this can simply be tiles, sheet metal, or other non-flammable materials. Some manufacturers specify a 30mm base. This can be made of a fire board, paving slabs, granite, or other solid materials that don’t transfer heat. Some manufacturers require a 50mm air gap below the base. Always check the installation instructions, and if in doubt apply all of the above to ensure your boat stove base is safe.
Unless specified diffently by the manufacturer. Hearth bases should extend at least 150mm to the sides and back of the stove, and at least 225mm to the front.
Behind the stove and to its sides, the guidelines require fire boards of 25 mm thickness to be fitted. These need to be fixed in a way that leaves at least a 10 mm gap behind the board, preventing heat from being transferred directly onto the boat’s wall paneling. Fire boards can then be tiled or glad in other non-flammable materials.
If the above is not achievable, please contact us. We sell inherently save boat stoves that come with built-in hearth and heatshield options. With this type of setup, there is no need to construct a hearth on the boat. Take a look at the Go Eco Adventurer. It is very economical to run, with up to 50% less fuel consumption, and we offer a free installation on this stove.
Traditionally, flues for solid fuel and diesel boat stoves were of the single skin type and made from mild steel. However, this has created problems in the past and accidents have occurred, some of them fatal. Single-skin flues made from mild steel can rust. This means over time they can develop holes and gases will escape into the boat. Holes in the flue can be very small to begin with and the boat owner may not necessarily notice this straight away. Even a small hole can be enough for carbon monoxide and other gases to escape, posing a serious health risk.
The other problem with single-skin flues is that the gases traveling inside them cool down too fast. Cold gases will not rise well in the flue. All it takes is a windy or wet day and the adverse weather conditions can create a backdraft, which will draw carbon monoxide and other gases back into the cabin.
For this reason, boat stoves should be fitted with stainless steel twin-wall insulated flues. These keep the smoke inside them hot and help gases to rise. Twin wall flue systems also tend to be made from stainless steel or other non-corrosive materials, which means they will not rot and likely won’t have to be replaced for the lifetime of the stove.
Read the manufacturer’s instructions to check what flue length is required. Many stoves are not safe to use on boats as their design requires a 4.5-meter flue to be fitted. If you find that the stove on your boat is not suitable for short flues, do not be complacent about it. Short flues can lead to carbon monoxide build-up, which can be life-threatening.
Flues should be cleaned regularly. We recommend having your flue swept at least once a month if you are running the stove daily.
Providing enough ventilation is an important part of any safe boat stove installation. Every solid fuel or diesel stove needs an air supply. As the fire burns it will consume the air inside the boat’s cabin, which needs to be replaced. There should be a completely open vent of 550mm² for each 1kW of stove output, preferably divided between vents at high and low levels.
When calculating your ventilation requirements, it is also important to look at any other air-consuming appliances in the boat. These can be gas cookers, boilers, extractor fans, dryers, or anything else that removes air from the boat. All air removed from the cabin needs to be replaced by a vent. If you are unsure, you can check the data sheets of your appliances or contact us for more information.
General Condition Of The Stove:
When considering boat stove safety, it goes without saying that the burner on your boat should be in good condition. But what exactly does that mean? Your stove should be inspected with its annual service, to make sure that the stove body is in good order. There should be no cracks, gaps, or other signs of damage. The fire brick liner should be intact and fire bricks should be free of cracks and gaps. The door seals should be attached solidly and make for a tight fit. The boat stove must be securely fixed to the hearth, to prevent it from moving.
It is worth noting that this is by no means an exhaustive list, and regulations change all the time. Always use an experienced engineer, with proper marine public liability insurance. Always follow Boat Safety Scheme guidelines, industry standards, and the manufacturer’s instructions to ensure your boat stove is as safe as it can be.
Make sure that you have functioning carbon monoxide and smoke alarms. These should be tested at least once a month. Alarms should be suitable for boats and labelled BS EN 50291-2 for carbon monoxide alarms, and BS EN 14604:2005 for smoke alarms