Why has my air conditioning stopped cooling?
First check for yourself that it's set to cool and lower than the room temperature, that the filters aren't full of dust (switch it off first and just look behind the front cover), and that the outdoor unit is clear and free of ice. If it still won't cool after that, give us a call: some refrigerant may have leaked out, and only a certified technician is allowed to work on the refrigerant.
CHECK FIRST
Three things you can check yourself
- 01
Is it set correctly?
Check on the remote that it's set to cool or heat, and that the temperature is set lower than the room if you're cooling, or higher if you're heating.
- 02
Are the filters full of dust?
Switch the air conditioning off and open the front cover. If the filters are full of dust, mention it when you call.
- 03
Is the outdoor unit clear?
Check that nothing is up against or in front of the outdoor unit, and that there's no ice on it.
Just look: don't put your hands or anything else inside the unit. If it's leaking water, switch it off and call us.
What you can see for yourself
You can find most of these causes yourself without any tools, just your eyes and the remote.
It isn't set correctly
On heat it won't cool, and on fan only the fan runs. In dry mode it takes moisture out of the air while keeping the temperature as steady as it can. On a Mitsubishi Heavy Industries remote, you choose cooling with the MODE button: it's called COOL.
On AUTO it decides for itself whether to cool or heat, depending on the temperature. Set it to cool instead, with the temperature lower than it is indoors.
A low fan speed, or an eco or quiet mode, won't cool as hard. And if you've just changed something, give it a few minutes: after you switch it off and on again, it waits a moment before it starts, to protect itself.
If several indoor units share one Mitsubishi Heavy Industries outdoor unit, they can't cool and heat at the same time: if you set a second indoor unit to a different mode, that one only blows air. So set them all to cool.
The filters or the inside are dirty
A filter full of dust lets less air through. Mitsubishi Heavy Industries says a clogged filter can affect cooling, make the unit louder and use more electricity.
Depending on where it hangs, the inside can also get dirty after a few years, and then it doesn't perform as well, the same manufacturer says. A regular service cleans the filters and the evaporator. If the dirt goes deeper, it needs an intensive clean or a deep clean.
If the filters are full of dust, mention it when you call. How to tell what your system needs.
The outdoor unit can't get rid of the heat
Air conditioning cools by moving the heat from your room to the outside. The outdoor unit releases that heat into the outside air, and for that, air has to be able to flow past it.
If a wheelie bin, a plant or garden furniture is up against it, or the grille is full of leaves, it cools less well. Daikin and Mitsubishi Heavy Industries both say the same: keep the air inlet and outlet of the outdoor unit clear.
On a very hot day it can cool less anyway, Daikin says: it has to get rid of its heat into air that's already hot.
If you see ice on the outdoor unit, mention it when you call.
The room is too warm for it
If windows or doors are open, the sun is shining straight in, or there are lots of people or warm appliances in the room, it has more work to do. Close windows and doors, and keep the sun out with curtains or blinds.
If the air conditioning is too small for the space, it often won't reach the temperature you want on a hot day. A service won't change that. It needs more capacity. Give us a call and we'll work out what it needs.
A JOB FOR THE TECHNICIAN
Refrigerant doesn't get used up
The refrigerant, the substance that flows through the pipes and, when cooling, carries the heat outside, sits in a sealed circuit and doesn't get used up. If there's too little in it, it has leaked out somewhere. Just topping it up won't help for long. The leak has to be found and fixed.
A temperature sensor or the circuit board, the electronics in the unit, can also fail. Mitsubishi Heavy Industries and Daikin systems report faults like these themselves, just like low refrigerant: a light flashes or a code appears. Mention it when you call, so the technician knows what to bring.
Only a certified technician working for a certified company is allowed to work on the refrigerant. That's set out in Article 10 of the EU F-gas Regulation, and it includes repairs and topping up. So never buy refrigerant online yourself: according to the Dutch Human Environment and Transport Inspectorate, a lot of illegal refrigerant is in circulation.
When to call straight away
Switch the air conditioning off and call us straight away if:
- water is leaking from the indoor unit
- a light is flashing rapidly or an error code is showing
- you hear a strange noise
- a fuse keeps blowing or the trip switch keeps tripping
- you can smell burning
- it still won't cool after the three checks above
A slowly flashing light can be normal. A Mitsubishi Heavy Industries unit does this, for example, while it warms up before heating, or while it removes moisture from the indoor unit after cooling.
Just look: don't put your hands or anything else inside the unit, and don't try to repair it yourself.
Before next summer
Don't wait for the first hot day. Mitsubishi Heavy Industries recommends having inspection and maintenance done in the off-season. With a maintenance plan, we book the service for you, and you go to the front of the queue if it does break down.
QUESTIONS
Quick questions
Can air conditioning run out of refrigerant?
Not by itself. The refrigerant sits in a sealed circuit and doesn't get used up. If there's too little in it, it has leaked out somewhere, and the leak has to be found and fixed.
Can I top up the refrigerant myself?
No. Only a certified technician working for a certified company is allowed to work on the refrigerant (Article 10, Regulation (EU) 2024/573). And never buy refrigerant online yourself: according to the Dutch Human Environment and Transport Inspectorate, a lot of illegal refrigerant is in circulation.
What does a repair or a breakdown cost?
That depends on what's broken. If something needs repairing or replacing, you'll hear what it is and what it costs first, and we only go ahead once you've said yes. If you're on a plan, you go to the front of the queue.
Do you service my brand?
Very likely. We service all the common brands, such as Mitsubishi Heavy Industries, Mitsubishi Electric, Daikin, LG, Panasonic, Toshiba, Samsung and Haier, even if another company installed your system.
Sources
- User's manual, air conditioner SRK20-50ZS-WMitsubishi Heavy Industries Thermal Systems
- Operation manual, Daikin room air conditioner FTX25KMV1B and FTX35KMV1BDaikin
- User reference guide, Daikin room air conditioner CTXA15 and FTXA25-50Daikin
- Maatgids voor airconditioners (air conditioner sizing guide, in Dutch)Daikin
- Regulation (EU) 2024/573 on fluorinated greenhouse gases, Articles 3 and 10EUR-Lex
- Tips voor consumenten bij onderhoud en installatie van airconditioners en warmtepompen (consumer tips, in Dutch)Human Environment and Transport Inspectorate (ILT)
- Airco en ventilatoren (air conditioning and fans, in Dutch)Milieu Centraal
All sources accessed on
WHO ANSWERS
Rein Gerritse
Owner, customer contact and installations
Rein owns Airco Holland together with Peter Reijling. Every article includes what he sees in practice, and he checks it before it goes online.
More about Rein and PeterStill not cooling? Give us a call.
Tell us the brand and what you've already checked, so the technician knows what to bring. If you're on a plan, you go to the front of the queue, and if you still have to wait, we bring you a loan unit.
READ NEXT
More questions about your air conditioning
Does air conditioning need topping up every year?
No, the refrigerant in your air conditioning goes round a closed circuit and doesn't get used up. If it needs more, something is leaking or too little was put in at some point, and a certified technician should find out which before topping it up.
Why is my air conditioning leaking water?
Water from the indoor unit is almost always condensation, not refrigerant: usually the condensation drain is blocked or the filters are dirty. If the outdoor unit drips while it's heating, it's usually just defrosting and not broken.