Some CR-V's have a partially clogged heater core which restricts the flow of coolant to the driver's side of the heater core, this causes the heat temperature to be lower coming from the driver's side vents than the passenger's side vents.
Technical Service Bulletin # 14-063
2012 Honda CR-V
vin numbers starting with 5J6, 2HK, and 3CZ
2013-14 Honda CR-V
Low Heat from the
Drivers-Side Vent Fix
The good news is, you don't have to replace the heater core to resolve the issue. The repair procedure involves flushing the heater core with a special heat pump and a commonly bought cleaning product called CLR. Details of the cleaning process include;
1.Flushing the heater core for about 1 1/2 hours with CLR.
2.Flushing again with regular water for about 15 minutes.
3.Drain and fill the engine and radiator with new coolant.
4.Remove air pockets from the system, and top off coolant.
I'm writing this article to show that there is a fix for low heat from the drivers-side vent without removing the heater core, but I'm not writing it so you attempt to do the procedure yourself. Any Honda dealer will have the tools to do the job, or you could try a radiator shop, they should be able to help you without removing the heater core as well.
Replacing the heater core involves a lot of work; one problem is you need to remove the entire dash because the heater core is located on the firewall. The cost of replacing the heater core would be about 10 hours of labor, plus parts. The cost of flushing the heater core is about 2-3 hours with the exact same results, saving you hundreds of dollars.
If you have any questions about this problem, leave them in the comment box below and I will be happy to answer them for you.
This is what a heater box and heater
core look like
Above is a heater box behind the dash with the dash removed. Below you will see what an actual heater core looks like outside the heater box.