The Pre-Winter Service:
What to Check on Gas Heaters Now

A gas heater that refuses to fire on the coldest morning of the year is a nightmare your client will not forget. The callout is reactive, the client is furious, and the parts you need are probably backordered. Pre-winter servicing fixes all of that. It fills your schedule before the rush, protects your clients, and keeps cash flowing through autumn. Everything you need to stock up before the season, from flame sensors to hot surface igniters, is in our Trade Shop. The time to move on this is now, not when every other tech in Melbourne is chasing the same components.

Table of Contents

• Why Pre-Winter Servicing Protects Your Business
• The Heat Exchanger Check: Start Here
• Carbon Monoxide is the Risk You Cannot See
• Ignition Components to Inspect
• Filter and Airflow: The Quiet Killer
• What to Have on the Truck Before May
  
  

Why Pre-Winter Servicing Protects Your Business

Gas ducted heating sits dormant for six to eight months. That downtime does real damage. Seals dry out, sensors collect carbon deposits, and capacitors degrade without a single warning sign. Then the client flicks the unit on in late April and you get the call.

Energy Safe Victoria is direct on this point. Annual gas appliance servicing is the most effective way to prevent carbon monoxide incidents in Australian homes. That is not a statistic you want to be associated with from the wrong side.

A pre-winter service round also keeps your diary predictable. You are not scrambling for reactive callouts or waiting on parts. You are booked, stocked, and in control of your own schedule.

The Heat Exchanger Check: Start Here

This is the most critical inspection on any gas ducted service. A cracked heat exchanger allows combustion gases into the supply air stream. That is a direct CO risk.

What to Look For

Run the unit and observe the flame. It should be stable and consistently blue. Yellow or orange flickering, particularly when the supply fan kicks in, indicates combustion disruption.

Check for soot streaking around the heat exchanger body. Dark staining at seams or ports is a warning sign that demands further investigation. Do not dismiss it as cosmetic.

Place a calibrated CO detector at the supply diffusers while the unit runs on heat. Any reading above zero at the grille requires immediate action. Red-tag the unit, document it thoroughly, and make the client understand exactly why. There is no grey area here.

Carbon Monoxide is the Risk You Cannot See

Every service vehicle should carry a calibrated CO detector. CO is colourless, odourless, and lethal at sustained concentration. Clients experiencing headaches or fatigue through winter often have no idea the source is their heating system.

Your role is to catch this before it becomes serious. If you identify a CO risk, the unit does not stay operational. Isolate it, red-tag it, and refer to Energy Safe Victoria for your obligations as a licensed gasfitter. The documentation requirements are specific and non-negotiable.

This is also the conversation that builds long-term client loyalty. A client who understands you just protected their family will not be calling your competitor next year.

Ignition Components to Inspect

• Hot Surface Igniters

These are the number one cause of no-heat callouts at the start of winter. They crack without warning and give no prior indication of failure. If the unit is more than five years old and you are already on-site, a proactive igniter replacement is a straightforward conversation to have with the client.

• Flame Sensor Rods

A fouled flame sensor causes intermittent lockouts and confused clients. Carbon deposits accumulate on the rod surface during normal operation. Clean it with fine steel wool. If the rod is pitted or corroded, replace it outright. The part is inexpensive. The return callout is not.

• Gas Valve and Manifold Pressure

Check inlet gas pressure against the manufacturer's specification. Verify burner pressure on both high and low fire settings. A pressure drop under load points to a failing regulator or gas valve. Identifying this in April is a minor fix. Identifying it in the first week of June is a headache.

Filter and Airflow: The Quiet Killer

A blocked filter is a slow-motion heat exchanger failure. Restricted return airflow causes the heat exchanger to overheat on every cycle. Over time, that thermal stress creates the cracks you are finding on units with no service history.

Pull the filter and photograph it before and after the replacement. It takes thirty seconds and gives the client a visual they will not forget. It justifies the filter cost without you having to justify it verbally.

With the unit running, check that the supply fan is drawing correct current. A motor running hot or pulling high amperage is heading toward failure before next winter. Check capacitor condition with a meter. A failing capacitor shows no external signs until the motor dies completely, usually on the coldest night of the year.

What to Have on the Truck Before May

Once the cold snap arrives, component stock thins out fast. Get ahead of the season now. The essentials to have on the vehicle before the rush:

• Hot surface igniters in the common sizes for the brands you service
• Flame sensor rods
• Motor run capacitors
• Gas regulators
• Filter stock across common return air sizes

Having these on the truck means you close out calls on the first visit. That efficiency is what turns a one-off service client into a recurring booking every year. For units where tight ceiling clearance is a factor, it is also worth familiarising yourself with the Compact Comfort range, which is built specifically for spaces where filter access on a standard unit becomes its own challenge.

Get stocked before the rush. Visit us at Dandenong South, Keilor Park, or Shepparton to go through what you need for your service round. If you need to check gas compliance documentation for appliances you are working on, our Compliance Certificate page has the relevant resources.

Keilor Park: saleswest@vicair.com.au | 03 9365 1900
Dandenong South: saleseast@vicair.com.au | 03 8770 2800
Shepparton: salesshep@vicair.com.au | 03 5833 4700

Contact Our Team Today

FAQs

Q: How often should a gas ducted heater be serviced?

Annually. Energy Safe Victoria recommends annual servicing for all gas appliances. In practice, many units go years without attention, which is why pre-winter is the most reliable time to reach out to your existing client base.

Q: What should I do if I find a cracked heat exchanger?

Red-tag the unit, do not leave it operational, and advise the client in writing. Document your findings and refer to Energy Safe Victoria for your specific obligations as a licensed gasfitter.

Q: Can I service the gas components without a gas licence?

No. Electrical and mechanical work on the air handler can be carried out by a licensed electrician or refrigeration mechanic. Any work on the gas circuit, including the burner, valve, manifold, or flue, requires a licensed gasfitter.

Q: What is the most common cause of no-ignition callouts in winter?

Failed hot surface igniters and fouled flame sensor rods account for the majority of first-call no-heat faults. Both are inexpensive and fast to replace on-site.

Q: How do I know if a capacitor is failing

A motor that starts sluggishly, runs hot, or draws higher than rated current is a strong indicator of capacitor degradation. Test with a capacitance meter. A visual inspection alone is not reliable.

Q: What does a yellow or flickering flame indicate?

Incomplete combustion, which can be caused by a partially blocked burner, incorrect gas pressure, or a compromised heat exchanger. Investigate the cause before leaving the job.

Q: Where can I source gas heater spares quickly before the winter rush?

Vic Air Supplies stocks heating spares across our Dandenong South, Keilor Park, and Shepparton branches. Call ahead and we will have what you need ready for pick-up.