A common problem on the Renault Zoe is the heater stops working and it blows cold air only. There are a few of causes of this, but try the following steps to diagnose:

Turn of ECO mode

Firstly, make sure you do all testing with ECO mode turned off. In the winter, if you want heat, do not use ECO mode as this restricts energy consumption and reduces the effect of the heating.

Don't turn fan too high

Because the Zoe uses a heatpump, the heat isn't plentiful, so you should just set the desired temperature and press Auto, so the fan speed is automatic. Turning the fan speed up too high can expel all the heat quicker than the heatpump can generate it and you will end up with cold blowing air.

Try a pre-conditioning

Set a pre-conditioning schedule and see if the cabin warms as it should do. If it does, then you know there isn't a physical problem with the heatpump system. If it doesn't get hot, then you know that the heatpump isn't working and it will probably require a visit to the dealership. It is most likely that it needed regasing - see below. If it does work, then continue trying these steps below.

Adjust heating controls

Some users report that just 'messing around' with the heater controls will kick it back into life. So try:

• taking it in and out of AUTO mode

• turn air con on and off (when button is lit red it is off)

• adjust temperate control  max to min

Some users report that the heater works better with the air conditioner off. Try it. But this shouldn't be the case and if it is, it points to a problem which needs to be fixed.

Do not repeatedly use pre-conditioning

There are reports that using the pre-conditioning multiple times (no matter which method used to activate) can disable and confuse the heat pump controller.  So do not repeat a pre-conditioning without driving first. I assume this is fixed by a software update - see below.

Hair dryer trick

In a similar way 'messing' with the heater controls can kick the heating back into life, heating the external temperature sensor with a hairdryer can do the same. Many users have found this method works:

• Lock the car and let it go to sleep for 15 minutes or so.

• Heat the outside temperature sensor to 15 deg or more with a hair dryer or hot wet blanket. The sensor is the lump underneath the driver's door mirror (on UK right hand drive vehicles).

• Unlock and start the car.

• Select the minimum temperature and auto mode. This should already activate the heat pump as the car will try to cool the car.

• Watch on the R-Link for the outside temperate to drop as the sensor on the mirror cools down.

• Now select a hot (or maximum) temperature, once the outside temperature has dropped (obviously stop heating the sensor), the car should heat again.

One user wrote: "I can confirm that this does work! Blasted the sensor with a hair dryer for about 30 seconds. Sensor registered 22C. Stuck the air con on at its lowest setting and ran it for a couple of minutes. Switched the hair dryer to cold and cooled down the sensor until it went down to 14C. Outside temperature is 4C. Whacked the temperature up to full in the car and about 2 minutes later weh-hey! Thank you, thank you, thank you - still booked in to Renault though."

Air conditioning re-gas

If the air conditioning system is low on refrigerant, then this will also stop the heating working on the Zoe. If you find your Zoe is making a loud grinding noise when the heating is on, then this is also likely to be the cause. Low levels of refrigerant is the most common source of heating problems with the Zoe.

Vehicles typically lose around 50 grams of refrigerant per annum. Keeping this topped up at the correct level is critical on some EVs, especially on Renault Zoes. The refrigerant carries oil around to lubricate the system as it circulates. Insufficient gas could result in compressor failure over time.

If the system is low refrigerant, it means there is a leak in the system, which is normally due to a dry rubber seal. The problem is compounded with electric cars as users tend to not use their air conditioning as much, to preserve energy. This results in seals drying out and then eventually refrigerant leaking. The Zoe also uses the air conditioning to cool the battery during rapid charging, so if the car is mostly charged at 7kW, the air conditioning may not be getting used enough. You should be using your air conditioning at least weekly to keep all the seals lubricated.

The next step is to get the refrigerant (gas) level in the system tested and check for leaks. If the vehicle is under warranty, get a Renault dealer to do this. If there's a leak, then this should be covered under warranty. Don't let the dealership try to charge you for gas though, as the loss of gas was the result of the leak! If the car is out of warranty, then it would be cheaper to take it to your local general garage. Most garages can carry out air conditioning re-gas work. The Zoe uses R1234yf gas and has a total capacity of 1,000 grams. Check the garage has this first, as many smaller garages will not keep this type, as this is only used on the latest vehicles. Be aware though that this new gas is expensive and the Zoe uses a lot of it! An alternative would be to use a mobile air conditioning service. Search on Google for "mobile air conditioning regas" to find local or national firms that cover your area. A mobile service is more convenient as they come to you at home or work, are often cheaper too and probably have better diagnostic skills if required.

Often just getting a re-gas is enough to fix the problems and make the heating work again.

Get software updated

If you still have heater problems, get a Renault dealer to check the software version. Many users have had the 'bugs' fixed by having the latest software loaded. If you find the heater is temperamental and it works some days and not others or it works initially, but then when you adjust the heating, it then starts blowing cold, then it is highly likely your car needs a software upgrade.