Gas tankless, and the number the marketing leaves out
Endless hot water, a much smaller footprint, and the lowest running cost of the gas options. It is also the technology most often sold to people it does not suit, because the install is where the money goes and the headline flow figure describes a condition your house never sees.
How it works
There is no stored water. A burner fires only when a tap opens, heating water as it passes through a heat exchanger, which is why the hot water never runs out and why the unit costs nothing to run when nobody is home.
The limit is not volume, it is flow. A tankless unit can raise water by a certain number of degrees at a certain number of gallons per minute, and those two figures trade against each other. Ask for more flow and you get less temperature rise.
- Several showers or fixtures genuinely run at once
- You want the floor space back
- Your gas service is already adequate for the load
- You are replacing an existing tankless unit
- You expect to stay in the house long enough to see the payback
- Gas line, venting or electrical work can double the job
- It needs annual descaling, and hard water makes that non negotiable
- You are buying it mainly to lower the bill
- Nobody local services the brand you are being quoted
What it costs
We model the installed price from the equipment price, because you can look up the box and you cannot look up everything that gets added to it. Ranges only, and never a single average.
- Rule of thumb
- roughly 3 to 4 times the price of the unit on a conversion
- Equipment, retail
- $1,300 to $2,800
- Typical installed
- $4,200 to $9,000
- Time on site
- 4 to 8 hours, sometimes across two days and two trades
What the work portion buys
- Labour, a much longer job than a tank swap
- Permit and inspection
- New venting, which a conversion almost always needs
- Gas line work where the existing line cannot carry the unit
- A dedicated electrical circuit for condensing models
- Condensate routing
What it costs to run
About $296 a year in fuel on our Turlock model, the cheapest of the two gas options and roughly $163 a year better than a gas tank. Divide that into the conversion premium before you treat it as a saving.
Those figures come from our Turlock fuel model, which is the one market where we hold both published utility rates. They will be in the right region for anywhere nearby and they are not a national average, so treat them as a comparison between technologies rather than a prediction of your bill.
Who makes it
Brand comes after technology, always. Once you have settled on this one, these are the manufacturers we hold research for.
Solid entries have a page. Dashed entries are in the research but not yet written up, and we would rather show you that than link you nowhere. All brands
Ask your installer these
- What flow does this model give at my winter design rise?
- Will this run on my existing gas line, or does it need upsizing?
- What venting does it need, and does my run allow it?
- Does a recirculation loop change my warranty?
- Who descales it, how often, and what does that cost?