Demand Hot Water Heaters
In Alberta you are not allowed to use a "Hot Water Heater" to provide
more then 75,000 Btu for space heating. www.swisswatch.me
If you live in a diferent jurisdiction - you need to know your local codes
before trying to use a "Demand Hot Water Heater" for heating.
In Canada you are not allowed to use glycol in a demand hot water heater
as it is not certified as a space heater.