I was attending the service call for tankless water heater n found its not a direct vent.has there any code reference that tankless water heater has to be direct vent in Ontario and why?only reason I can think about it that it will be not enough combustion air to operate.
I would follow the manufacturers installation manual
Some appliances are approved to be installed as either direct vent or non direct vent. If the water heater is installed as a non direct vent appliance it will still need an air supply. You must follow the Gas Code Clauses 8.2 to 8.5 when sizing the air supply.
In some locations only a direct vent appliance can be installed.
QuoteClause 7.26.1 - A water heater, unless of the direct-vent type, shall not be installed in a bathroom, bedroom, or any enclosure where sleeping accommodation is provided.
A power vent water heater may be installed in an enclosure adjacent to a bedroom or bathroom provided adequate combustion air per clause 8.2.6 is provided to the enclosure. THis combustion air supply shall not be supplied from the bedroom or bathroom.
A natural draft water heater may be installed in an enclosure that is accessed by a pedestrian door which can be opened from a bathroom or bedroom, provided that the enclosure has a volume equal to or greater than the bathroom or bedroom.
The unit is 200000 btuh.also the house built 25 yes ago.but I found the install manual and as per it require some outdoor air.so get to fix that too.Thx for your reply.look like heading to busy season as cold is approaching. Time to put the running shoes.