Either you are out of gas, or it is not getting enough air. This may be due to a blocked inlet at the bottom, or a stopped-up flue. This is a dangerous situation. Clear anything from around the bottom of the heater and check the flue inside and outside the house. If it continues, do not use the heater and have it checked by a professional.
When carbon is ignited, it burns with a blue flame.
When ignited, hydrogen burns with a pale blue flame.
Copper burns with a green flame when ignited with oxygen.
Potassium has a violet color in the flame test.
A Bunsen burner works by mixing gas and air in a controlled manner, which is then ignited to produce a flame. The gas flows through a tube and is mixed with air at the base of the burner. The mixture is then ignited at the top of the burner, creating a hot, blue flame that can be used for heating purposes.
An oil fired furnace works by using oil and a flame. The oil is sent through a tube to the burner area of the furnace and when the oil is ignited with a lighter, the flame can be adjusted according to how much heat is necessary.
When carbon is ignited, it burns with a blue flame.
When ignited, hydrogen burns with a pale blue flame.
Copper burns with a green flame when ignited with oxygen.
Potassium has a violet color in the flame test.
Flame throwers work by spraying a jet of ignited fuel onto a target.
With a direct fired system the airflow goes directly over the flame. An indirect fired air heater has a heat exchanger that the air passes over. Indirect units provides heat without contamination from combustion by-products.
Gasoline is a fluid that is easily ignited. It is highly flammable and can quickly catch fire when exposed to a spark or flame.
Probably the flame sensor.
The flame of strontium nitrate is red. It produces a bright red color when ignited.
The water heater flame sensor detects if the burner flame is lit. If the flame goes out, the sensor shuts off the gas supply to prevent a dangerous gas leak. This ensures the water heater operates safely and efficiently by only allowing the burner to function when the flame is present.
if you live in the UK you can buy a blue flame heater from TGS Industrial supplies Ltd