What are the differences between the yellow and the blue flame?

The blue gas stove flames show that everything is OK, while the red and yellow may be a sign of incomplete combustion and danger.

With hydrocarbon flames, such as gas, the amount of oxygen supplied with the gas determines the rate of combustion, flame colour and temperature. In all cases, with the use of LPG, except or the decorative gas fireplace flames, the flame from a gas appliance burner MUST BE BLUE.

The colour of the flame is determined by the temperature
Gas Colour Temperature
LPG (Propane) Blue 1,980°C
Natural Gas (Methane) Blue 1,960°C
LPG or Natural Gas Yellow 1,000 °C
Temperatures are approximate.

Blue flame temperatures assume complete combustion.

With enough oxygen, you get complete combustion and an LPG flame burns at a temperature of around 1,980°C. For Natural Gas (Methane), the temperature is about 1,960°C. A yellow gas flame is indicative of incomplete combustion and carbon monoxide emissions. Yellow gas flames only burn at around 1,000 °C.

Do you remember the lessons in chemistry at school? If you had the chance to use a special burner, you have watched how the flame color varies depending on the amount of oxygen being fed. When oxygen is increased, there is a complete combustion, which is indicated by a blue color. The reason is that in the case of complete combustion, enough energy is generated to ionize the gas molecules in the flame.

Complete Combustion:

Gas + Oxygen = Water + Carbon Dioxide + Heat

Remembering the burner experiment from school, you can also notice a red or yellow flame. The colour is due to the heating of very fine soot particles that are produced in the flame. This type of flame burns only at about 1 000 ° C and releases dangerous carbon monoxide.

To burn properly LPG requires an air-to-gas volume ratio of about 24:1. For the natural gas, it is about 10:1.

Incomplete combustion:

Gas + Oxygen = Water + Carbon Dioxide + Carbon Monoxide + Heat

In case of a yellow or red flame, contact an expert!

Remember – whenever you observe a yellow or red flame or a blue flame with a yellow tip, contact a specialist to check the LPG system. Contact an expert, also if you notice yellow-brown soot around the gas stove or if you smell unpleasant, sharp odour.

The cases above may be due to gas loss and / or carbon monoxide emission indoors, which is extremely dangerous. Inhalation of carbon monoxide can lead to headaches, dizziness, confusion, convulsions and loss of consciousness.

Always make sure the flame is blue and read the instructions for using propane-butane products. Regular inspections of the instruments by a specialist are also mandatory.

If you would like to consult our experts about the installation, we have provided, do not hesitate to contact us at 0700 20204.