I have a 2008 Honda CRV. I have been having an ongoing problem with lack of heat. This started about three months ago. My mechanic replaced the thermostat (twice) we thought we might have gotten a defective one. We flushed the radiator and heater core forward and backward and under pressure. Still very little improvement. Took the car to local dealer who advised that the radiator and heater core needed to be replaced. Had my mechanic replace the radiator for far less than the dealer. No improvement. We cut open the old radiator and could find no sign of corrosion or obstruction that would restrict the flow of coolant through the system. It does not seem logical that if there is no restriction in the radiator there shouldn’t be any in the heater core. The dealer had advised that it appeared that the blend doors and controls seemed to be operating properly, although what little heat we were getting was not consistent through all dash vents. There was a noticeable difference between the drivers side (colder) and the passenger side. We decided to replace the water pump. some slight improvement but not much. Noticed that it seemed as though the coolant fans behind the radiator seemed to come on more than necessary. I pulled the fuses for these fans and drove the car for nearly a half an hour with no change in engine temp and no improvement in heat. I am well aware of the monumental task to replace the heater core and the potential for other things to go wrong as a result. The car has over 130,000 miles. Last option would be to look for replacement and move up a couple of years.
Does anyone believe this is definitely a problem with the heater core or does anyone have any other ideas either from experience or any anecdotal information. At this point I am supplementing the heat with two 12 volt electric heaters.
Any info or suggestions would be greatly appreciated