How a califont works
Rheem describes gas continuous flow as heating water on demand rather than heating it and storing it until needed. Open a hot tap and the unit fires; close it and the burner stops.
'Califont' isn't a brand or a separate kind of heater. Makers simply call it gas continuous flow. Rinnai's INFINITY range is one example, and Rheem sells continuous flow models alongside its gas storage heaters. If you'd rather keep a tank, see gas hot water cylinders or the wider hot water cylinders section.
What decides a califont install
| What the gasfitter looks at | |
|---|---|
| Gas pipe size | Rheem says a continuous flow heater needs a larger diameter pipe from the gas meter than most storage heaters. Coming from a gas cylinder can mean new gas pipe. |
| Gas type | Piped natural gas, or LPG from refillable bottles where there's no piped supply. The model has to match. |
| Flue and ventilation | Gasfitting includes flue and ventilation pipes and making sure ventilation is adequate. |
| Water connections | Hot water to basins, baths and showers must still be delivered at a temperature that avoids the likelihood of scalding, as clause G12 requires. |
Signs your califont needs a gasfitter
- No hot water, and an error code on the controller.
- The unit doesn't fire when you open a hot tap.
- Water that runs hot, then cold, during a shower.
- Black marks or soot near the unit, or where the flue exits.
- Water dripping from underneath it.
The gasfitting rules
Under the Plumbers, Gasfitters, and Drainlayers Act 2006, every part of gasfitting is restricted, so only an authorised person may work on the gas side. A gasfitter in the restricted class isn't allowed to hook an appliance up to the supply. Where the Board is satisfied a licensed gasfitter is competent, that person can also plumb the water lines in and out of a gas water heater.
WorkSafe sorts gas jobs into three risk levels. A first califont in a home is general gasfitting. Adding to or altering an existing gas installation is high-risk. A straight swap for an equivalent unit counts as low-risk only when nothing else moves: same pipework, flue, pressure, gas type, ventilation and energy use.
Certificates at the end
Once the work is connected, the person who connected it (or their supervisor) issues a Gas Safety Certificate if they're satisfied it's safe. General and high-risk work also needs a gas certificate of compliance before it counts as finished; for low-risk work that one is optional.
Rinnai notes that the installer of an INFINITY unit must issue a certificate of compliance by law, and that a warranty claim may be invalid without the gasfitter's registration number and the gas certification number. File them with the house papers, because a gas retailer or LPG supplier can ask to see one before supplying you.
Smell gas near the unit?
Leave the unit alone and don't strike a flame or use switches. If you can reach the meter or bottle safely, shut the gas off there. Get people outside, and if anyone is at risk, ring 111. Our gas leaks page has more.
Checks you can make
You can
- Try the gas hob or another gas appliance.
- On LPG, check the bottles aren't empty and the changeover is on the full one.
- Write down any error code the controller shows.
- Keep the flue outlet clear of plants and clutter.
Leave to an authorised tradie
- Opening the unit or touching its gas controls.
- Gas pipe, flue and ventilation.
- The water connections to the unit.
- Issuing the gas certificates.
Questions to ask the gasfitter
- Is our gas pipe big enough for continuous flow?
- Natural gas or LPG for this model?
- Which risk class is this job, and which certificates will I get?
- How will bathroom hot water be kept from scalding?
- Is servicing part of the warranty, or separate?
What we would do
Before choosing a califont over a cylinder, have a gasfitter check your gas pipe and where the flue can go, because those decide most of the job. When it's finished, don't let anyone leave without the gas certificates. A continuous flow gasfitter will expect you to ask for them.