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The lack of control over the building temperature was leading to a number of complaints from customers and frustrated staff for this busy office.

The faults we found

Picture of FCU controllerAster Maintenance took over the HVAC maintenance of this medium-sized office building in West London from another provider. The building’s owners reported a severe lack of control in many of the office areas, leading to complaints from their staff and visitors.

One of our first tasks was to undertake a building-wide survey of all the HVAC plant - main Air Handling Units (AHUs) and the local Fan Coil Units (FCUs) to establish why there were so many problems.

Some of the issues found were faulty items of equipment such as actuators or FCU controllers, but the majority were controllers being set up or wired incorrectly. There were also a large number of valve actuators that had been removed for unknown reasons, and left ‘hanging’ by their wires.

What we had to do to solve the problems

Aster Maintenance undertook a programme of works to reinstate full control to all areas by addressing these problems in stages. We rewired one complete office area, where a replacement controller had been fitted that was incompatible with the valves it was attempting to control, thus leading to no control at all!

We completed the work by fitting a replacement discrete temperature controller to the building’s main AHU, in conjunction with fitting a new diverting valve on the heating coil. The existing valve had seized, having not operated for a considerable period of time due to being incompatible with the AHU controller, which had itself failed.

The building also benefitted from Aster Maintenance replacing a failed expansion bellows and a failed expansion vessel on the heating system, which were identified during our very first maintenance visit.

The occupiers have been delighted with the restoration of temperature control to their office areas. Aster are currently undertaking the replacement of a number of complete fan-coil assemblies which have been isolated due to coil failures in the past.

These works are a part of the owners’ on-going investment programme to bring the building back to full serviceability.


If your commercial building is suffering from poor temperature control our qualified M&E engineers will be able to diagnose the immediate action required, or offer advice on our HVAC maintenance contracts.

If you’d like to request a call back please get in touch.