Diesel Heater in Your Workshop? Fumes, Size and Fuel Explained

Your workshop is cold and a diesel or paraffin heater looks like the answer. But is it safe to run indoors, and will it fill the place with fumes?

Match the heater type to your ventilation first, then choose the size and fuel. PartsForMachines lists nearly 60 heaters from Sealey, SIP, Draper and Clarke in its diesel, paraffin and kerosene heater range, from flued infrared units to indirect space warmers.

Can I Run a Diesel Heater Indoors Without a Flue?

Only if the heater is made for it and the space is well ventilated. A direct-fired heater sends all its combustion fumes into the room it heats, so it is unsuitable for poorly ventilated buildings. Burning paraffin or diesel uses up oxygen and can produce carbon monoxide, so fresh air has to replace the oxygen and carry the gases away.

For a poorly ventilated space, choose an indirect heater with ducting, such as the ABI1000COMBO indirect heater, whose 5m duct takes the exhaust away from the heated area. Flued infrared models such as the 18037 diesel heater with flue kit must use their flue in enclosed areas without good ventilation.

Infrared or Blown Air: Which Warms a Workshop Better?

Infrared suits draughty or part-open buildings and warming the people at the bench; blown air heats the air of the whole building and works best with the doors shut. An infrared heater warms people and objects directly rather than the air, so you lose less heat when cold air rushes in through an open door.

Fanless models such as the IR13 13kW infrared diesel heater move no air, so they run quietly and do not stir up dust. A blown-air heater uses a fan to spread warm air round the space.

What Size Heater Do I Need for My Workshop?

Match the maker's heating area to your building, measured the same way. Some makers quote floor area in m² and others volume in m³, so work out both: a 6m x 8m workshop has 48m² of floor, or about 180m³ under a 3.75m roof.

For scale, the 18037 is designed for about 66m², the ID51 15kW infrared diesel heater quotes about 350m³ and the AB1008 up to 800m³. Treat these figures as a guide: a draughty, poorly insulated building is harder to keep warm, so allow some extra. To compare ratings, 1kW is roughly 3,400 BTU/hr.

Will It Run on Kerosene, Paraffin or Diesel?

Many heaters burn more than one fuel, but some are diesel only, so use only the fuels named for your model. The Space Warmer heaters run on kerosene or diesel, and the Fireball XD heaters take diesel, paraffin or kerosene.

Industrial infrared models such as the IR13 and IR16 are for diesel only. Where kerosene is allowed, check the grade the manual asks for: several Draper heaters need grade 2 or higher. If a fuel is not named for your model, do not use it, and ask our team if you are unsure.

What Should I Check Before I Buy?

• Heater type against your ventilation: direct-fired, indirect, or infrared with a flue
• Output in kW and the maker's heating area, compared with your building
• The fuels named, and the kerosene grade if you plan to burn kerosene
• Power supply: 230V, or dual voltage if you work on 110V sites
• Safety and controls: flame-out cut-off, overheat and tilt shut-off, thermostat and timer

Not sure which suits your workshop? Contact the PartsForMachines team by WhatsApp, telephone or email with its size and how it is ventilated, or browse the diesel, paraffin and kerosene heater range.

Product options, delivery options and returns terms are shown on each product page. A 30-day return policy applies to eligible items.

Frequently Asked Questions

Do diesel heaters cause condensation?

A direct-fired heater can. Each litre of fuel burned releases roughly a litre of water as vapour, which stays in the room unless ventilation carries it away. An indirect heater sends its combustion by-products out through its flue instead.

Should I use a carbon monoxide alarm with a workshop heater?

Yes. Paraffin and other fuel-burning heaters can produce carbon monoxide, which has no colour or smell, so you cannot tell it is there; a headache is one symptom. Fit a CO alarm and keep the space well ventilated.

Why does my heater smell or make my eyes sting?

Treat it as a sign that combustion fumes are building up because ventilation is poor. Improve the ventilation or choose an indirect or flued model; Draper calls the flued 18037 almost completely odourless.

How much fuel does a workshop heater burn?

It depends on output. For example, the 18037 uses as little as 0.9 litres of diesel an hour, the IR13 about 1 litre and the 105kW XD350 about 9.5 litres. Multiply the hourly figure by your running hours and fuel price.

Will a diesel heater trip my electrics?

Unlikely: it draws little power, because the fuel makes the heat and the electricity mainly runs the burner, pump or fan. The 18037 uses 40W for 11.6kW of heat, and the IR20 motor draws 110W.

Can a diesel heater run on a 110V site supply?

Some can. The AB500DV dual-voltage space warmer switches between 230V and 110V when you swap its supplied plug and cable, and two larger Clarke heaters change over automatically. Check the supply of any other model before you buy.

Can I burn red diesel in a workshop heater?

Only if your use qualifies. Red diesel is restricted to a short list of uses; in Great Britain, for example, these include heating non-commercial premises. Check the fuel duty rules where you are before you fill up.

Is it safe to run a flame heater while spray painting?

No. Paint and solvent vapour is flammable, so keep naked flames and portable heaters away from any spraying. Never use solvents, lacquers or aerosol sprays near the heater.

What flue parts do I need for a flued heater?

Only the flue parts made for your heater. The IDX44 and IDX54 come with a three-piece stainless flue kit that takes the fumes out through a wall, and the IR13 accepts optional stainless extensions and bends. Follow the heater's instructions for fitting.

Why does my heater keep cutting out or not light?

A safety device may be doing its job. A flame-out device cuts the fuel if the flame goes out, and some models also shut down when they overheat, tilt or run low on fuel. Check the fuel level, type and filter, then contact our team.