Some of you may know that the first combined clothes/dishwasher was invented by a female engineer, but don’t let the domestic setting fool you; Margaret A. Wilcox was the engineer that also invented the first car heater, all the way back in 1893. Without her foresight, we might have still been driving round with fogged up windows and wearing too many layers to be comfortable, but even then, Henry Ford didn’t start fitting ‘proper’ heaters until 1929, with the Ford Model A.
Today, car manufacturers spend many millions on ensuring comfort levels are priority, and as drivers, we really don’t give much thought to what goes into the process—the reliability and comfort of cars is just taken for granted. But what happens when things do go wrong with your car's heater?
In this article
- Common Faults with a Car Heater
Car Heaters—The Basics
Essentially, a car heater is a pretty basic thing, or certainly, the premise of it is. Hot water from the engine is circulated through a heat exchanger or matrix, air is blown over the heated matrix and delivered to the vents on the dash, or in the footwell.
That’s all very well in theory, but in reality, it’s slightly more complicated. We need to be able to adjust the speed & volume of the air flow, choose which direction it flows, and of course, regulate just how hot (or cold) the air reaching us is. It’s not simple.
This means that the system incorporates servo motors, switches, fans, pipework, ducting, wiring and diverters. Any one of these components could fail, the relatively good news is that statistics say they won’t.
Car Heater Problems
While the stats say that reliability is good, as we pointed out in another post, manufacturers are using millions of components each year, and where possible, a single component is used across the range, which means that even just a 0.1% failure rate could be well into the thousands. Volkswagen delivered close to eleven million vehicles in 2019.
A great number of vehicles also complicate matters further by having air conditioning or climate-control installed, but that’s a whole different system that needs a separate article to fully understand, so we’re concentrating purely on the ‘heater’ system here.
Identifying the most common failure with a car’s heater system isn’t easy, but the good news is that newer vehicles tend to be very reliable, aside from user errors (such as having fizzy drinks poured over the controls, or even through the air vents). Rodent infestation can also be a problem, particularly if they get caught in the blower.
However, it’s worth pointing out that the components inside the system have a tough life, purely through the heating/cooling processes that they go through; constant expansion and contraction of the components can lead to premature failures, and of course, heat does have a tendency to dry things out, including lubrication or sealed components.
Typically, the two most common failures are the heater blower motor, and the heater matrix.
Cost to Replace the Heater Matrix
The average price for a full heater matrix replacement is £964.41 through the independent network, and £1252.74 through the main dealers. In the majority of our research, Manchester-based independents are consistently cheaper than everywhere else.
The heater matrix (in most cars) is typically buried within the dash/footwell area, requiring around five to six hours labour to remove and refit everything, so it’s an expensive job unfortunately. The prices quoted here are for everything start to finish, including labour, parts, coolant and miscellaneous.
We’ve used our ever favourite Ford Fiesta to get quotes for a heater matrix replacement, these range from Perth to Penzance, and Sleaford to Swansea. It’s really no surprise that Knightsbridge has the most expensive dealer quote (some £348.94 more expensive than the highest charging independent in Abingdon), but even we’re a little taken aback by the overall difference: £617 between the highest quote and the lowest.
Cost to Replace the Heater Blower Motor
The average price for the heater blower motor replacement, including all parts and labour works out to £290.93 through the indy network, and £349.73 with the main dealers.
The blower motor is a relatively simple job, needing just one to two hours of labour to complete, and the prices between independents and main dealers are much closer—just £58.93 separates the average price between the two.
With that said, again, the Knightsbridge area has the most expensive main dealer rates (in our study), coming in at £67.26 more expensive than the independent dealer in Abingdon, or £152.10 above the Manchester independent.
- Q: My heater is only blowing cool air. What could be the problem? #1
- A: It’s possible that air has become trapped within the system, which could also mean a coolant leak somewhere. Get your local repair shop to diagnose the problem sooner rather than later—if you have a coolant leak, you could be risking your engine.
- Q: My heater is only blowing cool air. What could be the problem? #2
- A: It could be that the controls or the diverter flap have failed or stuck in the cold position. Can you hear anything moving when you adjust the settings from cold to hot? Depending on the age of the car, you may be able to feel mechanical resistance in the movement, or hear a servo motor working. If the controls feel loose, or you can hear nothing, it’s likely that you’ll need to get it checked over by a professional.
- Q: There is no airflow through my heater vents, even at full speed. Is the heater blower motor broken?
- A: The very first thing to do is to check the fuses to make sure none of them have blown. If you aren’t sure where to find your fuses, either look in the owner’s handbook, or do an online search. There are usually some spare fuses located within the fuse box, replace the blown fuse but also remember to replace the spare.
- Q: My heater seems to make a squeaking/rattling noise when in use. What can I do?
- A: Unfortunately, aside from having the blower motor repaired or replaced, there is very little you can do to alleviate the noise.