Gas Heaters – Carbon Monoxide (CO) Testing – June 2021

Background

Known for their quality and reliability, Rinnai gas heaters have been keeping Australians warm for over 50 years.  They are fully certified to meet all Australian performance and safety requirements. 

Like all electromechanical appliances, gas heaters require routine checking, servicing and maintenance. This includes the heater itself, as well as additional field installed items such as flue systems and gas fittings.

In the interests of safety, regulatory authorities including Energy Safe Victoria (ESV), recommend servicing gas appliances at least every two years.  Such servicing is required to be carried out by a suitably licensed gasfitter.  For gas heaters with flue systems, this service work should always include a test for CO spillage.

Testing for CO spillage applies to all heaters with flue systems.  It does not apply to unflued heaters (also referred to as flueless or portable heaters).  Refer to Annex A for detailed heater type and model information and to see whether this testing is applicable to your Rinnai heater.  

Open Flued Gas Heaters (OFGHs)

OFGHs use air from the room to support combustion.  These particular heaters can be a source of CO spillage into the home, due to:

• Inadequate room ventilation:
  • Possibly since the heater was first installed
  • As a result of changes to the building envelope (e.g. draft proofing and reduced permanent ventilation measures)
  • As a result of rangehood or exhaust fans that are in operation during heater use.
• Faulty flue, fireplace or chimney
• Incorrect installation
• Faulty heater

It is important the servicing gasfitter carries out the test for CO spillage in strict accordance with a prescribed test methodology to ensure valid results; that is, to avoid results that indicate a CO spillage concern when there actually isn’t one.

If a test for CO spillage correctly confirms a concern, the servicing gasfitter is required to determine the cause.  In the vast majority of cases this will be inadequate room ventilation.  Rinnai is not aware of any reports of a faulty Rinnai OFGH being the cause.

Room Sealed Gas Heaters (RSGHs)

Unlike Open Flued Gas Heaters, RSGHs do not use air from the room to support combustion and are therefore not affected by room ventilation. If a test for CO spillage indicates a concern, in the vast majority of cases it will be as a result of an incorrect installation or severely damaged product. Rinnai is not aware of any reports of a faulty Rinnai RSGH being the cause. 

Prescribed Test Methods

The Australian Standards for gas appliance servicing and gas installations (AS 4575 and AS/NZS 5601.1 respectively) contain prescribed methods for testing CO spillage.  The Victorian regulating authority, Energy Safe Victoria (ESV) also provides guidance to gasfitters in their ‘Gas Information Sheet 38 Testing for negative pressure and carbon monoxide spillage while carrying out gas service work’.  Your licensed gasfitter will be able to decide which method(s) to apply.     

 Summary:

• All gas heaters with flue systems (including those fitted into a fireplace or chimney) should be serviced and tested for CO spillage at least every two years by a suitably licensed gasfitter
• The servicing gasfitter must conduct CO spillage testing in accordance with a prescribed test method. If such testing correctly confirms a concern, the gasfitter is to determine the cause(s). 
• Rinnai is not aware of any reports of a fault with a flued Rinnai heater being the cause of a CO spillage concern.
• Once the cause of a CO spillage concern has been determined it must be actioned by a licensed gasfitter in accordance with the requirements of the relevant gas safety regulatory authority.
• Rinnai 1stCare, a division of Rinnai Australia Pty Ltd, provides a full range of factory-direct checking, servicing and maintenance.

Annex A:

Table 1:

Heater categories with Rinnai models for which CO spillage testing is required.

Table 2:

Heater categories and models for which CO spillage testing is not required.