Heat only when set to 90, otherwise cold air?

[ShadowSentry]

I have an 05 Path and just two days ago I noticed a problem. Started the vehicle and let it idle with the heat on. came out 10 minutes later and it was to operational temp but it was blowing cold air even with it set at 83. If the controls are set to 90 it will burn you out with the heat it blows, which is normal, but anything else it is set to temp, mode it will blow cold air even with the vehicle in motion. Anyone know if this is a bad climate control switch or something?

[DanJetta]

Could be. I would burp the coolant system first, though. There are instructions on here somewhere, but it's easier to have someone do it the next oil change.

[ShadowSentry]

I'm going to look for the directions for the burp. But if it were air in the lines wouldn't that cause the heat to not work at any setting?
It works best and normal when set to 90 degrees when the path is at idle or driving and is never disrupted.

[DanJetta]

In theory, you're correct, but there are a few other factors at play (how much air is in there, the condition of your coolant, etc.). When I had air in my lines, the heat did work—but only on the hottest setting and when I was driving.

There may be another issue but the burp is an easy first diagnostic step. I did the burp in my driveway (and got coolant all over everything) and improved the heat slightly—enough to be convinced this was the issue. Went to the dealer and had them do a fluid flush with a pressure bleed (forgot what they call it) and the heat was back to new. Definitely worth the money.