We work hard to ensure that the air conditioning works correctly on all of our trains. We’re sorry if you’ve found the carriage temperature to be uncomfortable. If you complete the feedback form then we’ll pass the details of the problem directly to our Fleet Team who will look into the problem as soon as possible.
How does the air conditioning on the trains work?
The temperature on our class 357 trains is regulated by a set of independent carriage onboard computers. When the train is in service each carriage looks to reach and maintain a temperature of 21 degrees. However, when the train has been out of service the temperature may fluctuate by five degrees in either direction, depending on the temperature outside the train.
For example, if it’s cold outside then the carriage interior will be 5 degrees hotter, if it’s warm then it will be 5 degrees cooler. When the train comes back into service the system will look to address this to get back to 21 degrees.
Fixing it when it doesn’t work
There may also be occasions where the onboard systems fail, and we take steps to fix this where possible. Failing air conditioning may not be a fault in the air conditioning unit itself – it could be linked with how power feeds directly into the unit. There are two units that supply power to a carriage, one is the Primary power unit (essential systems) and the other Auxiliary unit (non essential systems), if the power draw on the Primary unit drops below a threshold it will take power from the Auxiliary system instead.
An engineer is based at Fenchurch Street whose role is to check the onboard systems and reset the system when a fault is found. Should this not rectify the issue then our Fleet Team will address it as soon as they can. Please be aware the onboard heating can take time to fix as the layout requires the removal of seats from the carriage.
If you experience a particular carriage has an issue, there can be a variance in temperature so changing where you sit may help. If not, changing carriages could be, where practical, a solution. Please report any faults in the form above and we’ll aim to get them fixed as soon as we can.