Why doesn’t my car heater work?Resolve your car heater issues with our expert advice

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Fair pricing

Fair pricing

We negotiate competitive rates with garages to offer the best prices, on average 30% cheaper than main dealerships.

Vetted garages

Vetted garages

We personally select and vet only the best local garages, fully covered by a 12-month warranty on parts and labour.

Collection from your door

Collection from your door

Our fully insured Fixter Heroes offer a contact free collection and delivery service, with flexible time slots that suit you.

Advisors on your side

Advisors on your side

Our in-house experts make sure any quotes you receive are relevant and fairly priced, so no nasty surprises!

Why has my car heater stopped working?

The first thing to check is your coolant. It’s one of the most common causes of a failing car heater and the most easily rectified. If your coolant level is where it should be, then it could be one of a wide range of alternative issues: electrical or mechanical.

Remember—safety first! Always let the car and its components cool down before examining a hot system for faults. You don’t need a trip to A&E as well as one to the garage.

What are the common causes of a broken car heater?

Risk level – Medium

What to do – Find the faulty component and replace it.

Faulty thermostats are the most common reason for a failing car heater. The thermostat is responsible for ensuring the engine operates at the correct temperature and using the coolant to adjust the levels. If it’s faulty or broken, it affects the heating system as well as your car’s performance.

There are also a few valves that could block or stick over time, and after years of regular use, the controls on your dashboard might have finally jammed or developed faulty connections.

There’s a faulty valve, switch or thermostat

Risk level – High

What to do – Top up your coolant straight away, and then check for leaks.

When the coolant level drops below a certain point, the hot fluid can’t find its way into the heater core, resulting in a cool cabin. It’s one of the simplest problems to rectify, as most motoring depots will carry pre-mixed coolant for every make and model. However, driving with an overheating engine is dangerous, so don’t take any risks if your temperature gauge is heading into the red.

You’ve run out of engine coolant

Risk level – Medium

What to do – Replace or refurbish your heater core.

It’s less likely to be a heater core issue than many other causes, but it still happens. If debris or particulates infiltrate your coolant system, they can clog the core, preventing the heat from dissipating.

There could be a blockage in your pipes or heater core

Risk level – Low

What to do – Replace the fan if it can’t be repaired easily.

If your heater fan isn’t moving any air, then you’re incredibly unlikely to feel the benefit of the heated air within the system.

Your heater fan has broken

Risk level – Low

What to do – Check the fuses and power distribution.

It could be a blown fuse, faulty wiring, or a short in the system. Whichever your problem, they’ll all prevent the fan from powering up and delivering the hot air you need.

There’s an issue with the power supply

It all depends on what’s causing the problem. You could expect to pay anywhere between £250 and £550 for most electrical or mechanical issues—or around a tenner, if your car only needs topping up with coolant.

How much does it cost to fix a car heater?

Troubleshooting your car’s heater means checking radiator levels, reservoir bottles, fan vents, and fuses. After that, you’re looking at repairs or replacements requiring specialist tools and experience. In that case, you’re going to need a professional diagnosis.

How do I reset my car heater?

If your car heating system is in good working order, it should adequately produce the temperatures you need for everyday driving. However, if it fails to heat your car sufficiently—and the problem isn’t due to any of the topics already discussed—it could be that the hot air is escaping, or there’s a problem with your engine.

How do I make the heat in my car hotter?

If your car heater doesn’t turn on at all, the chances are it’s the switch, the power supply, or the fan that has stopped working. Of course, you can try lubricating the switch to bring it back to life, but ultimately, if that doesn’t get things moving, it’s time to call the experts.

What would cause a heater not to turn on?

If you aren’t sure where your car heater problem lies, then one of our trusted mechanics will. Book in with Fixter, and we’ll run a diagnostic test or examine your heating system to uncover the issue. Once we know where the problem is, we’ll run you through all the solutions, their costs and have you toasty and warm again in no time.


Thought fixing your car was a time-consuming headache? Fixter can handle it for you

Pick-up and delivery — anywhere ✌️

Hassle free! Our fully-insured drivers collect your car at the time, date and location of your choice; then deliver it right back when and where you want it.

All work approved by our expert team 🔍

Our in-house experts approve your car’s service at every stage. If a service or MOT reveals something unexpected, we’ll call you immediately to explain the situation and make a recommendation. No additional work will ever be carried out without your approval.

Every booking is covered by a 12 month warranty 🏅

Our in-house experts visit each garage in person and carefully select the most trusted servicing centres, based on our unique 25 point criteria including staff qualifications, equipment and customer ratings. Our policy guarantees that all mechanics are fully qualified, with 10+ years of experience. Your car is in the safest hands.

We only work with the top 5% garages in your area 🛠

We personally select and vet only the best garages, fully covered by a 12-month warranty on parts and labour - so if something happens, additional work and repairs will be undertaken without any additional fee

Your undefined is in safe hands with our top-rated mechanics


We personally select every local garage based on our unique 25-point criteria, which includes staff qualifications, equipment standards and customer ratings.

Fully qualified mechanics with 10+ years’ experience 👨‍🔧

Your car is in the UK’s safest expert hands.

Manufacturer-equivalent parts only ⚙️

Identical to your manufacturer’s, but much cheaper!

In-house experts approve all work personally 🔍

Every service carried out by our partner garages is fully reviewed.

12-month warranty on parts and labour 🛠

Any additional work needed will be carried out for free.

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Book a car repair in under 5 minutes

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Try Fixter today

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We cover all makes and models — anywhere in the UK

We cover all makes and models — anywhere in the UK

Need help or have any


Need help or have any


Our in-house experts are here to answer you car questions, Monday to Friday, 8:30am to 6:30pm.