Problems with heat on driver's side

I have a 2005 Impala. The heat quit working on the driver's side but still worked on the passenger side. We replaced the blend door actuator and reset the HVAC control system. It didn't seem to fix it right away but did eventually start working off and on which made me question if there was something wrong with the control panel. I put a new control panel in without fixing the problem. We have also hooked it up to scanners with no error code showing. There was a brief time after all of this where when you would stop at a light and the heat would not work on both sides and then when you get going it would heat up again. The car is warming up but there is just no heat on either side. Any ideas? Thanks.

Try back flushing the heater core?

One time I went round and round on a similar problem with no heat on one side, on a Trail Blazer......no codes....actuator was previously replaced and when checked out....it worked....no trouble found....guy comes back.....once again I check it out, ok....he left the vehicle at the shop and I drove it home, and then it happened to me.....checked actuator it was in the heat position.....

Called TAC.....they were running into a few instances like this....apparently, the diameter tubing of the radiators was smaller, and it was causing the heater core to plug up, in most cases it would happen on one half of the core(usually the lower half) so only one side got heat.....a back flush took care of it.....worth a try, if the actuator is ok....

I have a 2005 Impala. The heat quit working on the driver's side but still worked on the passenger side. We replaced the blend door actuator and reset the HVAC control system. It didn't seem to fix it right away but did eventually start working off and on which made me question if there was something wrong with the control panel. I put a new control panel in without fixing the problem. We have also hooked it up to scanners with no error code showing. There was a brief time after all of this where when you would stop at a light and the heat would not work on both sides and then when you get going it would heat up again. The car is warming up but there is just no heat on either side. Any ideas? Thanks.

both heater hoses must be hot. if this is not the case then it is restricted. remove hoses at engine and flush out with water hose at a low pressure. reverse hoses on flushing until the particles are gone. it is recommended to blow out with air after this to remove any other debris.

when replacing the coolant most do not flush out the heater core. this is a common collection area for some reason.

up in the cold areas this is required or you will not get proper heat.

debris in the air box can cause these air temp controller doors to malfunction.