Gas Hot Water Systems.Done Right.

How gas hot water works

A gas burner heats water in a storage tank, or heats it as it flows through a continuous flow unit. A flue carries exhaust gases outdoors. Gas units can supply hot water quickly and, in continuous flow models, without limit while the gas lasts. They need a gas supply large enough for the appliance and a flue that discharges safely.

Faults we see often

Common faults include a pilot that keeps going out, no hot water, lukewarm water, noisy burning, a dripping relief valve, water leaking from the tank and error codes on continuous flow units. Some are simple, like a blocked burner. Others involve a failed thermocouple, gas valve or heat exchanger. Gas faults are for a licensed gasfitter, not for guessing.

Gas safety

If you smell gas, leave the building, do not switch anything electrical on or off, and call your gas emergency number or 000 from outside. Yellow or orange flames, soot around the flue or a heater smell can signal poor combustion. Turn the appliance off and have it checked. Gas work in Victoria is licensed work.

Storage or continuous flow

A storage unit keeps a tank hot and suits homes with steady demand. A continuous flow unit heats water as it flows and suits homes that want hot water without a tank, but it needs a larger gas supply and a flue in the right place. A licensed gasfitter can tell you whether your gas meter and pipe can support the unit you want.

Flues, ventilation and position

A gas appliance needs air to burn and a safe route for exhaust gases. A flue must discharge away from windows, vents and eaves in line with the rules, and an indoor unit needs ventilation. Moving a unit or fitting a new one in a tighter space can change what is allowed, so check before you buy.

Servicing and pilot lights

A pilot that goes out may be caused by a draught, a worn thermocouple or a dirty burner. Newer units use electronic ignition instead of a standing pilot. Servicing by a licensed gasfitter checks the burner, the flue, the safety valves and the connections, and it can extend the life of the unit.

Efficiency, running costs and the future of gas

Gas hot water costs depend on gas prices, the efficiency of the unit and how much hot water you use. Check the energy rating on the label and compare it with heat pump and solar options before you replace a unit. Victorian rules about new gas connections have been changing, so check current information from the Victorian Government if you are building or moving a gas service.

What a replacement involves

A licensed gasfitter isolates the gas and water, removes the old unit, fits and connects the new one, checks the flue and ventilation, tests for leaks and commissions the appliance. Allow several hours without hot water. Ask for the compliance paperwork when the job is finished and keep it with your house records.

Questions people ask about gas hot water

What should I do if I smell gas?

Leave the building, avoid switches and flames, and call your gas emergency number or 000 from outside.

Why does my pilot light keep going out?

Common causes are draughts, a worn thermocouple or a dirty burner. A licensed gasfitter should find the cause rather than relighting it repeatedly.

Can a gas hot water unit be moved?

Sometimes, but the flue, ventilation, gas supply and clearances all have to meet the rules at the new position. Ask a licensed gasfitter before you plan a kitchen or bathroom layout.

Is a continuous flow unit better than a tank?

It depends. Continuous flow does not run out and has no tank to lose heat, but it needs a larger gas supply and may have a minimum flow before it fires.

How often should it be serviced?

Follow the maker's manual. Many gas appliances benefit from regular checks, and rentals have their own gas safety rules.

Continuous flow gas units: what to know

A continuous flow gas unit heats water only when a tap is open, so it can supply hot water as long as the gas flows. Size matters: a unit sized for a small home may struggle if two showers run together. Ask the plumber to match the capacity to your household and to explain temperature settings.

Continuous flow units need correct flueing, clearances and ventilation, and a gas supply that can deliver enough flow. These are installation details a gasfitter checks before quoting.

Gas storage systems and standing heat loss

A gas storage system keeps a tank hot, so hot water is available quickly but heat is lost through the tank walls. Newer tanks are better insulated. Check the manufacturer's energy information and the warranty, which differs between the tank and other parts.

If your gas bills are high, ask whether the system is the cause or whether leaks, long pipe runs or old insulation on pipes are wasting heat.

Gas supply, flue and clearance questions to settle before installation

A gas hot water unit needs a gas supply sized for its demand, a way to remove exhaust gases and clearances from windows, vents and combustible surfaces. Outdoor units are common because they simplify flueing, but the position still matters: it needs air around it, a safe place for the relief drain to run and access for servicing.

Before the gasfitter quotes, take photos of the existing unit, the gas meter and the planned position. Ask what the quote includes: removal of the old unit, a new tempering valve, gas and water connections, a pressure test of the gas line, and the compliance paperwork. Gas work is licensed work, so ask what certificate you will receive and keep it.

Guides worth reading

• Signs Your Hot Water System Needs Replacing
• Gas Appliance Safety Tips for Victorian Homes

Related plumbing services

• Hot Water Systems: Hot water repairs and replacement for gas, electric, heat pump and solar systems.
• Electric Hot Water Systems: Electric storage hot water repaired and replaced, including element and thermostat faults.
• Heat Pump Hot Water: Heat pump hot water installation and plumbing for lower running costs.
• Solar Hot Water: Solar hot water repairs, servicing and plumbing for roof and tank systems.
• Emergency plumbing is available 24 hours a day, 7 days a week

Talk to GSA Plumbing Services

Call 0401 041 103 or send an enquiry on the contact page. We work across Geelong, Melbourne and surrounding suburbs.