Continuous-flow hot water heats water as you use it. It can keep heating without a storage tank running empty, but has a maximum flow rate that depends on how much the water needs warming. For continuous-flow hot water installation in Canberra, check winter output and the outlets you run together.
Updated 18 October 2026.
Winter output: a worked temperature-rise example
For a hypothetical heater rated at 26 L/min at a 25°C rise, a constant-output approximation gives 26 × 25 ÷ 35 = 18.6 L/min at a 35°C rise, and 14.4 L/min at a 45°C rise. These are explanatory calculations, not certified performance for a Rinnai or Rheem model. Use its manufacturer’s performance chart for the actual selection.
Two showers, a kitchen tap and the unit rating
Two showers at 9 L/min require 18 L/min of mixed water; adding a 4 L/min tap makes 22 L/min. The hot-water share depends on the heater outlet temperature and mixing at each outlet. Ask the installer to calculate simultaneous hot demand against the selected model’s winter output. Gas pipe sizing, available supply and water pressure can also constrain performance. A larger heater cannot fix every upstream restriction.
Check the current model
Rinnai’s older Infinity 26 page is now marked discontinued and points to the Infinity B26 replacement. An installed, discontinued model may still be serviceable. Check its condition and parts availability before replacing it. For an existing fault, record the exact model and controller code before seeking service.
Does instantaneous mean instant hot water at the tap?
No. Water already sitting in the pipe between the heater and the outlet still needs to move through. The distance to bathrooms and the pipe layout affect the wait. Replacing a storage tank with continuous flow does not by itself eliminate that delay.
If waiting at a distant bathroom is your main complaint, explain that before choosing a system. Ask the installer whether location or distribution design is part of the problem.
Why might a plumber advise against continuous flow?
A plumber may advise against a particular installation because the supply, available space, winter output or cost makes it unsuitable for your home.
Ask which limitation applies at your property and which alternative would resolve it. Use Australian terms such as continuous flow or instantaneous when researching; overseas tankless advice may concern different products, fuels and requirements.
What can increase installation costs?
Changing from a tank to continuous flow may involve a different mounting position, gas supply changes, electrical provision, water connections and associated work. Ask for a site-specific scope. Do not assume that removing the tank makes the overall changeover simpler.
A like-for-like replacement of an existing continuous-flow unit also needs checking for model compatibility. Read how to compare installation quotes before committing.
What about Rinnai error codes?
An error code can narrow a service investigation, but it is not a diagnosis by itself. Record the exact code and model and follow the owner’s manual. Do not open the case, repeatedly reset a faulting appliance or work on gas components.
If you are deciding whether to replace an existing unit, compare parts availability and the diagnosed repair with the repair-or-replace considerations.
Discuss your installation
Compare continuous flow with electric storage and heat pump options, and check the exact model warranty. For gas hot water installation in Canberra, call Born Plumbing and describe your existing system, number of simultaneous outlets and winter complaints.