Gas Heating: Why is my airflow disrupted?

Gas heaters are advised not to be used for extended periods of time to maintain optimal operation. Recently, the Victorian Health Department issued a caution to gas heater safety and acknowledged that during this time at home, people are running their gas heaters longer than usual. Their advice is to follow recommendations from Energy Safe Victoria in regards to the upkeep and maintenance of gas heating systems. At Northwest Heating and Cooling, we are dedicated to providing you with updated information on warning signs and how best to look after your heating and cooling systems. 

What Heaters Apply to Extended Use? 

There are many gas heating systems on the market, and if your gas heater is not working properly we advise you to book in for a service. Heater systems that can be a concern when in use for an extended period include space heaters, gas log heaters, some gas ducted heating systems. 

Space Heaters

Space heaters are smaller portable gas heaters that are used to heat up small spaces such as part of a room. In the current climate, they are probably the most popular heater for the last-minute home office settings that are impacted by Geelong’s freezing winter. However, just because they are smaller does not mean they are more energy-efficient as they still require combustion to heat up a room and extended use can lead to the release of carbon monoxide and other hazardous gases. 

Gas Log Heaters

Gas Log Heaters are often the preferred and decorative fireplace for modern homes. These heaters provide ambience without the need for wood and constant cleaning. These heaters draw in outside air for combustion to heat an area. However, they do not have a high energy efficiency rating and it is recommended that they are not relied on to heat an entire room for an extended period of time. 

Gas Ducted Heating Systems

Some Gas Ducted Heating Systems have an open flue or power flue to create combustion and heat your areas. These systems will draw on air from the outside to begin the heating process. Without proper ventilation around the heating system, they can release carbon monoxide into your home. A draught diverter is also recommended for these heating systems to redirect the combustion without disrupting airflow if the flue is impacted by factors such as wind or exhaust fans. 

Northwest Heating and Cooling commonly install and service the following gas ducted heating systems. 

Both systems use a power flue or open flue to create combustion within their systems, under normal operating conditions these maintain the temperature of immediate surroundings. 


Negative pressure environment

One of the most common issues heating systems experience is a negative pressure environment. A negative pressure environment is when your home is experiencing a lower pressure than outside and is caused by there not being enough ventilation within a home. Not enough ventilation causes your exhaust system to draw in cold air from external openings, such as a flue.  Negative pressure is particularly common for gas heaters when left overnight. 

A negative pressure environment can affect the operation of your heating system and can be the reason your heating system is not working as well as it could be. Open flued gas appliances such as your heater are required to be tested for a negative pressure environment routinely. 

What is the recommended process for a gas heater with disrupted airflow? 

When you notice disrupted airflow, call in a qualified heating specialist to conduct a carbon monoxide test and negative pressure environment test. Both are undertaken to ensure there are no harmful gases causing the disruption. 

Negative pressure environment test

A negative pressure environment test (also known as a smoke test) is conducted when the heating system is off and cold. It is important that all external windows and doors are closed to ensure external factors do not influence the test. During the test, a heating specialist will use a smoke device such as a smoke match to determine the airflow. If the match shows the smoke being drawn into exhaust fans or away from the heater, windows will be open to equalise the air pressure and estimate how much ventilation is needed. A positive pressure environment test is when the smoke is attracted to the heater or down draught diverter as it ensures your heater is working correctly. 

Following a negative pressure test, a carbon monoxide spillage test will also be conducted to ensure that CO levels are not the source of the issue. This test will monitor leakages and spillages during 5 minutes of the heating system operating. 

How can you ensure you don’t experience disrupted airflow? 

Some of the ways you can ensure your gas heater is working correctly are: 

  • Having permanent ventilation installed: having your window open is not always going to be possible, particularly when it’s a wintery Melbourne day. So installing permanent ventilation into your space will prevent carbon monoxide from being redirected into your home. 
  • Don’t leave on for extended periods of time, once the room is warm switch it off. 
  • Don’t operate exhaust fans (such as range hoods) in the same area at the same time as it can create a negative pressure environment.
  • Consider installing a carbon monoxide detector. 
  • Have your heating system serviced every year by a North West heating specialist to ensure it is running safely. 

It is recommended you have your gas heater serviced at least once a year alternating between a regular service and a carbon monoxide test. Northwest Heating and Cooling are qualified heating and cooling specialists and can provide you with a comprehensive report following a heating system service. Get in contact with us by calling (03) 5277 1111.