Heat won't work unless AC is turned on with it...

[nerk]

I have a 2018 Nissan Leaf with a Heat Pump,

I think I'm running into my first "major" issue... Very strange behaviour happening with the heat function in the car, it just blows cold air... it's not extremely cold outside, about 3-5 degrees celsius, At first I thought my heat pump was dead, but here's the strange part... The heat does work, just as long as the AC is turned on with it, such as the case when you use the defrost button... I also confirmed it works just the same in other modes, front vents, floor vents etc... as long as you have the AC selected with it. Other strange behaviours I'm noticing is that if you push the recirculate button, it flashes spontaneously, almost randomly, not sure if its a code, pattern or just random... but its blinking rather than its normal behaviour to just stay lit.

Has anyone else come across some similar symptoms? I mean its not that big of a deal cause i use the heat with AC 95% of the time, just noticed this happening recently, but it could have happened a long time ago too, just never noticed...

Thanks in advance for any info anyone has to offer...

 

[knightmb]

That could mean your heat pump is not working, but your electric heating element is working. Normally when you switch on the heat, it uses the heat pump first and makes up the difference with the electrical heating element. When you switch both the AC and Heat on, since the AC is only to defrost the air, it needs to use the electrical heating element 100% to make the cabin warm. This is why it can work one way and not the other. As far as what is wrong with the heat pump, not sure.

 

[nerk]

interesting... thanks for the reply...

So the PTC heater is working instead of the heatpump... Is there a fuse for the heatpump specifically? or a relay I can try. I saw a few for AC systems, but couldn't find one that was related to the heat pump, or at least that I can decipher from the short form.

 

[nerk]

ok so strangest thing... My wife reported last night that its now back to "normal".

now I'm really confused, can't be a fuse if it's suddenly gone back to working again...

Any thoughts?

 

[knightmb]

ok so strangest thing... My wife reported last night that its now back to "normal".

now I'm really confused, can't be a fuse if it's suddenly gone back to working again...

Any thoughts?

She's certain that heat only mode made the heat pump come on? You can always tell because you can hear it running under the hood (radiator fans and heat pump itself). On PTC heat, it's completely silent under the hood, minus the cabin fan sound for example.