Few things can be more troubling than an indoor air conditioning unit that stops working. In some cases, the problem will only be an issue in summer when the temperature soars. But in many work settings, there is a lot of heat generated indoors and conditions will become uncomfortably hot without an air conditioning unit.

Not having a working air con is not an option. It can lead to unhealthy working conditions. Although there is no legal maximum indoor working temperature in the UK, the law does say it should be “reasonable”. Moreover, that heat can reduce productivity and also make visitors to the premises uncomfortable.

If doing nothing is not an option, what can you do? If the whole system has failed, bringing in new air conditioning installers may be the only solution, but it may not come to that.

There are various reasons that an air con may not be working. Therefore, it makes sense to check out the various possibilities first.

Most simply, it might not be faulty at all. It could be that the power has been disconnected in some way, or someone has unplugged it and simply forgotten to plug it in again. Amusing as it may sound, many an engineer has found this is the real issue! 

Faults may include problems with the wiring, the thermostat, or a tripped circuit breaker, which means the device itself works, but something around it needs to be put right.

More direct problems with an air con include it not blowing cold air due to a blocked filter, or a lack of refrigerant, sometimes due to a leak. Sometimes filters can be blocked or there has been a build-up of ice.

You can check some of these yourself and it may be that it is a simple problem with a simple solution like adding more refrigerant, or turning the unit off to allow it to defrost for 24 hours if there is an ice build-up.

Sometimes an air con has simply come to the end of its working life and needs a replacement. But there are many other things it could be.