023 Lightning (Build 08/23) – No Heat / No Defrost Heat – Dealer says “failed heater assembly” (any insight?)

[Balke]

Hey everyone — looking for some insight from the community while I wait on the dealer to finish things up.


I have a 2023 F-150 Lightning with about 48k miles. Recently the truck completely lost cabin heat — and defrost is also blowing cold, so it’s not just “weak heat.”


I checked coolant and noticed it was slightly low, topped it off to the max line, but it didn’t change anything.


The truck is currently at the dealership. At first the service advisor texted something about an “aux heat pump” (which confused me because I didn’t think my build had a heat pump). Now they’re saying it’s a failed “heater assembly” and they’re currently checking part availability.


I’ve seen a few posts online where people mention heater failures around certain build dates, but when I check my VIN I’m not seeing any recalls.


A few questions for anyone who has dealt with this:

1. When Ford says “heater assembly,” what part is that usually referring to on the Lightning? (PTC heater / HV coolant heater / valve / pump / heater core, etc.?)
2. Has anyone had this repaired around my mileage, and was it covered under warranty?
3. Any known TSBs or common failure points that match “no heat + cold defrost”?

I’ll update once I get the actual part number and codes from the dealer.


Thanks in advance.

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[OMO7]

You'll likely be on the hook for it. Keep us updated with the price.

 

[chriserx]

1) Yes, should be the same thing
2) Afaik, not covered after 36k, but you could always beg the BEV team. I swear the last paid one I saw was $250 part $750 labor or thereabouts.
3) Not that I'm aware, but PTC failures are generally supposed to be rare, and I think this makes the 5th or 6th one this winter.

 

[Balke]

If you're not having any performance issues and it's just a heater issue, that is a slippery slope. Can be argued both ways customer pay or warranty due to the fact the entire coolant system for both the battery and all HV equipment is one and the same as the one for the supplemental cabin heat. I read a warranty component list on Ford's pages but can't seem to locate it now. Your dealer is going to make that call regardless.

I did notice that while I was driving without heat for a week or so the battery temp was low and I have never noticed that before. It would always be dead in the middle. Could be that I use the scheduled trip everyday and while it was working it gets things to proper temp. My thought is if I opted to not fix this issue and the battery wasn't able to manage cold temps properly that this should fall under the 100k battery systems warranty. Could just be wishful thinking on my part.

 

[chriserx]

I did notice that while I was driving without heat for a week or so the battery temp was low and I have never noticed that before. It would always be dead in the middle. Could be that I use the scheduled trip everyday and while it was working it gets things to proper temp. My thought is if I opted to not fix this issue and the battery wasn't able to manage cold temps properly that this should fall under the 100k battery systems warranty. Could just be wishful thinking on my part.

It is strange that it isn't covered since if you attempt to charge in freezing weather it should throw a code. If it doesn't your truck would become a statistic.

 

[Balke]

It is strange that it isn't covered since if you attempt to charge in freezing weather it should throw a code. If it doesn't your truck would become a statistic.

Still waiting on word from dealership if it is covered. Sure hope so, all the ownership calculations I did to justify the truck were based on minimal maintenance costs.

 

[chriserx]

Still waiting on word from dealership if it is covered. Sure hope so, all the ownership calculations I did to justify the truck were based on minimal maintenance costs.

I hear ya, but minimal is not none either. I really would love to know what the failure mode of these PTCs are. In the event that it does need to replaced outside warranty, if you're up to it I'd be willing to pay you to ship it to me.

 

[Balke]

I hear ya, but minimal is not none either. I really would love to know what the failure mode of these PTCs are. In the event that it does need to replaced outside warranty, if you're up to it I'd be willing to pay you to ship it to me.

True. Yes, if I have to foot bill and get the part back I will ship to you. I have read that the PTCs that were in the recall had a bad solder joint. I have not seen any pictures or other details other than that. Coincidentally the Lightning I was going to get before this and almost completed the purchase had a stop sell placed on it bc of said recall and now mine has same part fail

 

[chriserx]

Ignore what I posted above. I was just thumbing thru my own Ford shop manual and forgot the 25 ym is different than 22-23. We have a heat pump system with the supplemental heat I spoke of. I'm not sure how your system works.

As far as I can tell it's similar setup, with an extra, higher efficiency heater added in the loop. I assume the difference is strategy, using the heat pump where possible and switching the PTC on to make up the difference where non heat pump models obviously just use the PTC for heat exclusively.

 

[RocketGhost]

A family member just had the PTC heater fail in his Mach-E. It was intermittent, sometimes it would heat and sometimes it would not. The only symptom was loss of cabin heat. No warnings on the dash. The dealer did a scan and there were lots of trouble codes thrown. The part was on backorder for about a month. He got the car back a couple weeks ago and it works fine now. Covered under 3/36 warranty so don't know the cost.

 

[FXYCYOT]

Just had this fail on my '23 XLT. Same symptoms as you. Cabin heater (PTC) failed. It ended up being covered under the warranty (22k miles currently on the clock). It was in the shop for 3 days, Ford was nice enough to supply a loaner while it was in there. Apparently, there was a code being thrown, but nothing that turned on the MIL. Also, I believe that there was a recall on the PTC's, something about a bad solder joint.

 

[TwentyTwentyThree]

1) Yes, should be the same thing
2) Afaik, not covered after 36k, but you could always beg the BEV team. I swear the last paid one I saw was $250 part $750 labor or thereabouts.
3) Not that I'm aware, but PTC failures are generally supposed to be rare, and I think this makes the 5th or 6th one this winter.

That sounds very very reasonable.

 

[TaxmanHog]

Watching for your fix report, please let use know the part numbers shown on the completed work order once you get her back.

 

[Balke]

That sounds very very reasonable.

Well I don't. I wouldn't expect to have a 1k plus repair for an EV under 50k miles. Unfortunately the preliminary research I have done says the repair could cost close to 2k so fingers crossed it will be covered since it should be considered an EV thermal / HV component

 

[TwentyTwentyThree]

Well I don't. I wouldn't expect to have a 1k plus repair for an EV under 50k miles. Unfortunately the preliminary research I have done says the repair could cost close to 2k so fingers crossed it will be covered since it should be considered an EV thermal / HV component

Ok. It is cheap. Go repair the hvac in any car, and you’ll find out.

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