It is 15 degrees outside, you are already late, and the vents in your EV are blowing air barely warmer than the driveway. The heated seats work and the car drives perfectly. Nothing feels broken except the one thing you need most on a freezing morning: heat. In a petrol car this would point at a thermostat. In an EV it can mean something else entirely, and the bill runs from nothing to more than $4,000.
The Numbers That Matter
3 to 6 kW: what a resistive PTC heater typically draws.
1 to 2 kW: what a heat pump needs for the same warmth, because it moves heat instead of making it.
26,681: the Teslas recalled in February 2022 over a heat pump software error that killed cabin heat and defrosting.
$2,400 to $4,500: what Tesla owners have been invoiced for a heat pump compressor and supermanifold replacement out of warranty.
~100 watts: what a heated seat draws, roughly one-fortieth of a full cabin heater.
The Short Answer
An EV heater usually stops working because of a failed heat pump compressor or valve, a dead high-voltage heater, a software fault, or a weak 12-volt battery. Check the temperature setting, charge level, and software version first, then check for a recall on your VIN. If those do not fix it, the repair is a dealer or EV specialist job: a coolant pump runs roughly $650 to $1,200, while a full heat pump compressor job can reach $4,500.
How an EV Makes Heat in the First Place
A petrol car gets cabin heat for free, as waste from the engine. An EV has no engine throwing off heat, so it has to manufacture warmth from the battery, and that changes how heating fails.
Three systems are in common use. A PTC heater is a ceramic resistive element behind the dashboard. It warms up fast, but it converts one unit of electricity into one unit of heat, so it draws 3 to 6 kW continuously on a cold day. Many early EVs, including pre-2021 Teslas and the Chevrolet Bolt, rely on it. A heat pump works like an air conditioner in reverse: it moves heat from the outside air, the battery, and the motors into the cabin, delivering two to four units of heat for every unit of electricity. A high-voltage coolant heater (HVCH) heats a coolant loop that warms both the cabin and the battery pack; BMW, Polestar, and several others use it, sometimes alongside a heat pump.
These systems share parts with battery thermal management. In a heat pump car, the same compressor that warms your hands also warms the battery before fast charging, so a heater fault can also mean slower charging. Our guide to whether a heat pump is worth paying for explains the efficiency side of the same hardware.
The Six Usual Suspects
No heat is a symptom, not a diagnosis. The table below covers the causes a technician works through, roughly in the order they check them.
| What you notice | Most likely cause | How it is fixed |
|---|---|---|
| No heat at all | Failed compressor, failed PTC heater, or a blown fuse | Part replacement at a dealer or EV specialist |
| Heat stopped in deep cold | Heat pump software fault or a valve stuck open, trapping refrigerant | Software update, sometimes a valve or sensor |
| Heat comes and goes | Failing sensor, software glitch, or a coolant pump starting to fail | Sensor or pump replacement |
| Weak heat, never reaches the setting | Low refrigerant, a clogged cabin filter, or a failing coolant heater | Leak check and recharge, filter change, or heater replacement |
| Heat driving, not when preconditioning | Software or scheduling fault | Update the app and car software, re-check schedules |
| No heat plus a warning light | Low coolant, a weak 12-volt battery, or a thermal system fault | Coolant top-up and leak check, or 12-volt replacement |
Two of these catch owners by surprise. The first is the software fault. In February 2022 Tesla recalled 26,681 Model 3, Model S, Model X, and Model Y vehicles because a software error could leave a heat pump valve open and trap refrigerant in the evaporator, stopping the compressor and killing both heat and windshield defrosting. The fix was a free over-the-air update. The lesson: before assuming a part has failed, check for a pending update or an open recall. The recall is documented in NHTSA’s recall acknowledgement letter for campaign 22V-050, and owners were still reporting heat pump failures in later cold snaps, as Notebookcheck’s owner reports show.
The second is the 12-volt battery. The big traction battery powers the heater, but the 12-volt battery runs the computers, valves, and contactors that tell it to switch on. A weak one can cause intermittent climate faults, and replacing one is cheap compared with the parts it mimics. Our guide to EV 12-volt battery problems covers the symptoms and cost. On Volkswagen’s MEB cars (ID.4, ID.3, Skoda Enyaq), the same confusion applies: only a proper diagnostic separates a PTC fault from a heat pump, valve, or sensor fault, as this specialist guide to MEB heating faults explains.
What a Heater Repair Actually Costs
Prices vary widely because “the heater” is several different parts. The ranges below come from owner invoices, repair guides, and shop price lists, and they are US prices unless marked otherwise.
| Repair | Typical cost | Notes |
|---|---|---|
| Software update or recall fix | $0 | Over-the-air where available; check your VIN first |
| Cabin filter replacement | $30 to $80 fitted | Often a DIY job |
| 12-volt battery replacement | $150 to $300 | Test it before replacing heater parts |
| Coolant pump (Tesla heat pump cars) | $650 to $1,200 | Part $250 to $400 plus labour |
| Heat pump valve or sensor repair | $900 to $2,200 | Refrigerant work adds cost |
| Compressor and supermanifold (Tesla) | $2,400 to $4,500 | One Quebec invoice was $4,476.55 |
| PTC heater (pre-2021 Model S, UK) | £500 to £800 independent, £1,500 to £2,000 at Tesla | UK pricing; US prices vary |
Two patterns matter. First, Tesla’s heat pump is built around an integrated valve block and manifold, so a failure that would be a $200 sensor swap on a modular system can become a whole-assembly replacement. A class action filed in Quebec in 2026 argues exactly that point, after an owner was billed $4,476.55 for a six-year-old Model 3. The coolant pump is the cheaper end of the same system: this Tesla coolant pump failure guide puts a professional replacement at $650 to $1,200. Second, some heater failures are covered by recall even years later: Polestar recalled about 3,150 early 2021-2022 Polestar 2 cars to replace faulty high-voltage coolant heaters, so check your VIN before you pay anything. Our breakdown of out-of-warranty EV repair costs puts the heater next to screens, suspension, and drive units, and our battery warranty guide explains what that warranty does and does not cover.
Five Checks Before You Book a Service Visit
They cost nothing and take ten minutes.
1. Check the setting, not just the temperature. Make sure the system is in heat mode, not stuck on AC, and try maximum temperature with the fan on high. If the vents still blow cold, the fault is real.
2. Charge the car and try again. A few models restrict cabin heating at very low charge. Plug in, charge above 30%, and retest while still connected.
3. Check for software updates and recalls. Install any pending update, then run your VIN through the NHTSA recall lookup. A no-heat fault with a matching open recall is a free repair, not a bill.
4. Try a full reset. A soft reset, or a full power-down and lock for a few minutes, can clear a climate glitch that survives a normal restart. If the heat comes back and stays back, note the date; if it fails again, that pattern helps the technician.
5. Check the cabin filter and the 12-volt battery. A clogged filter can cut airflow so far that the air feels cold even when the heater works. It is usually behind the glovebox and takes minutes to inspect. A 12-volt battery older than four years should be tested before any heater part is ordered.
If none of these changes anything, stop guessing. The heater runs on 400 volts, and diagnosis needs a scan tool that reads the thermal system’s fault codes. Ask before you book whether the diagnostic fee is credited against the repair; most good shops do that.
Is It Safe to Drive With No Heat?
For a short trip in mild weather, yes. For a cold morning commute, usually no, and the reason is the windshield, not comfort. A heater that cannot clear fog or ice from the inside of the glass is a visibility problem, which is why the Tesla heat pump fault became a federal recall: it failed a defrosting standard, not a comfort standard. If the windscreen will not clear, do not drive the car.
There is a second risk. In a heat pump car, the same system warms the battery, so a thermal fault can also slow DC fast charging and limit power. And in extreme cold, a car with no heat can become a genuine safety problem if you are stuck in traffic: the cabin is your shelter, and a heater failure plus a low battery is a combination to avoid. Cold also costs range even when the heater works, as our winter range guide explains.
What Winter Heating Costs You
Even a working heater is one of the biggest draws on an EV battery in winter. A resistive PTC heater pulling 4 kW for a 90-minute daily commute uses about 6 kWh a day just for warmth: on a car that does 3.3 miles per kWh, that is roughly 20 miles of range spent on heat, not driving. A heat pump doing the same job at a coefficient of performance of 2.5 needs only about 1.6 kW, so the same commute costs about 2.4 kWh, or roughly 8 miles of range. Recurrent’s November 2025 study of 30,000-plus US EVs found heat pump cars kept about 10% more range at 32°F.
Winter Heating Cost Calculator
Heater draw (kW):
Hours of heating per day:
Days per week you drive:
Electricity price (cents per kWh):
Heater type:
How the maths works: the calculator divides your heater’s power draw by its coefficient of performance (1.0 for a resistive heater, 2.5 for a typical heat pump), then multiplies by your hours and days. A month is counted as 4.33 weeks and a winter as 22 weeks. The default price of 18.3 cents per kWh is the US residential average from the Energy Information Administration, July 2026, and is only an example: replace it with your own rate. This is our calculation, not a manufacturer figure. The cheapest heat is the kind you barely use: heated seats draw around 100 watts each, so warming the person instead of the whole cabin can cut the heating bill by most of its value on short trips.
Frequently Asked Questions
Why is my EV blowing cold air when the heat is on?
Usually a failed heat pump compressor or valve, a dead high-voltage heater, a software fault, or a weak 12-volt battery. Check the heat setting, charge level, and software version first, then check your VIN for a recall before booking a repair.
How much does it cost to fix an EV heater?
A coolant pump runs about $650 to $1,200 fitted, a valve or sensor repair about $900 to $2,200, and a Tesla compressor and supermanifold job $2,400 to $4,500 out of warranty. Software and recall fixes cost nothing.
Does an EV heater drain the battery fast?
A resistive heater draws 3 to 6 kW, which can cut winter range by 20 to 40% on its own. A heat pump needs only 1 to 2 kW for the same warmth, which is why heat pump cars keep about 10% more range at freezing temperatures.
Is a broken EV heater covered under warranty?
Usually yes while the basic warranty lasts, and the battery warranty often covers the thermal system too. Once both have expired, the repair is on the owner, except where a recall or service campaign applies, so always check your VIN first.
The Short Version
An EV with no heat is usually telling you about one of four things: a failed compressor or heater, a valve or sensor fault, a software problem, or a weak 12-volt battery. The free checks take ten minutes, so do them before you pay a diagnostic fee. After that, the price is set by the part: a pump is a few hundred dollars, a compressor job can pass $4,000. And if the windshield will not clear, the car stays parked: a heater fault in winter is a safety problem first and a comfort problem second.
Written by Shurah, who researches and writes independently on the real cost of EV ownership — charging, maintenance, and total cost of ownership — backed by primary data and original calculations rather than recycled lists.
Heater components run on high-voltage power. Diagnosis and repair should be done by a qualified EV technician; never open the thermal system yourself.
