The two temperatures
A water heater has to satisfy two limits that pull in opposite directions. BC's plumbing code caps the water delivered to showers and bathtubs at 49 °C, because hotter water can scald skin in seconds. At the same time, stored water is often kept at around 60 °C to limit the growth of bacteria such as Legionella in the tank. The Government of Canada's guidance on water temperature and scalds sets out the same tension between storage temperature and fixture temperature.
The way out is to store hot and deliver cooler. A thermostatic mixing valve at the heater outlet blends cold water with the hot output so the water reaching the fixtures is held near 49 °C even when the tank is set higher.
Who is most at risk
Scald risk is not the same for everyone. Young children, older adults, and people with reduced skin sensation or mobility can be burned at temperatures and exposure times that would be uncomfortable but not dangerous for others. That is why the fixture limit is a code requirement rather than a preference, and why it applies to baths and showers in particular.
The limit also matters at the point of use: a mixing valve set once at the heater does not protect a tap that feeds only cold or a fixture with its own tempering valve. The assessment looks at where the hot water is actually used.
Mixing valves
A thermostatic mixing valve is a mechanical device that mixes hot and cold water to hold a set outlet temperature. It is the standard way to keep a 60 °C storage tank while delivering 49 °C to fixtures, and it is also used where a tankless unit is set higher than the fixture limit for a specific reason.
Installing or adjusting a mixing valve is plumbing work on the potable water system, and this site publishes no do-it-yourself instructions for it. A valve that is stuck, scaled or set wrong can deliver water that is too hot or too cold, so it is tested at the service visit.
Tankless set points
A gas tankless unit controls its own outlet temperature directly and commonly ships with a 49 °C default, which matches the fixture limit without a separate mixing valve. The set point can be raised, for example to feed a dishwasher or a specific application, but raising it above the fixture limit brings the mixing requirement back.
Because a tankless unit has no stored volume, its set point is also the temperature at the tap after the line clears. That makes the set point the main scald control on a tankless installation, and the reason the commissioning walkthrough confirms it.
Settings versus fluctuations
A temperature that is consistently too hot is a setting or mixing problem. A temperature that swings during use is a different fault: on a tank it can be a dip tube, a thermostat or a mixing issue, and on a tankless unit it is often flow, a fouled inlet filter or a sensor. The problem page on temperature fluctuations covers that diagnosis separately.
The distinction matters because the fix is different. Adjusting a set point does nothing for a unit whose outlet temperature rises and falls, and replacing a mixing valve does nothing for a scaled tankless heat exchanger.
What CANRO does
CANRO Heating & Cooling installs and services mixing valves and sets water-heater temperatures as part of an installation, replacement or service visit across its verified Metro Vancouver coverage. The set point and the mixing arrangement are confirmed at commissioning against the manufacturer's instructions and BC's fixture limit.
For a gas smell or a suspected leak, leave the building and call the FortisBC emergency line at 1-800-663-9911 or 911 first. This site publishes no do-it-yourself instructions for gas, venting, combustion or safety devices.