Motorised Valves
What are motorised valves?
Motorised valves are a common feature of newer heating systems. Simply put, they receive an electrical signal and open or close to allow or prevent the flow of water.
They have a valve body (the brass fitting connected to plumbing) and an actuator (the motor that sits on the brass body). When they receive an electrical signal, they activate. They can control heating zones and hot water demand, and can be either a two-port (single circuit) or three-port (dual circuit) valve.
When they start to wear out and fail, you may notice inconsistent temperature control, intermittent flow errors on your heat pump controller or unusual noises.
What does a motorised value do?
Control Flow: They open and close to control the flow of water to different parts of your heating system, such as the radiators, underfloor heat circuit or hot water coil.
Zone Control: In systems with multiple heating zones, motorised valves allow independent flow control for each zone. This means you can heat specific areas of your home without heating others. E.g. a three storey house might have 4 motorised valves, One per storey and one for the hot water demand
Automation: These valves are typically connected to your heating system’s thermostats or Heat Pump Controller, allowing for automated control of the heating, improving efficiency and comfort.
What happens when a motorised valve starts to fail?
Because motorised valves allow and restrict flow, when they start to wear out and fail, you may notice inconsistent temperature control, intermittent flow errors or unusual noises.
When the valve becomes energized, and fully actuates it activates an internal “switch” known as the auxiliary contact. This auxiliary contact sends a signal to activate other parts of your heating system(e.g. the thermostat turns on the motorised valve. the fully open valve sends the run signal to the heat pump) As the motorised valve deteriorates, this switch may fail to activate, leading to seemingly unrelated problems throughout the system.(e.g. the thermostat turns on the motorised valve. the light on the motorised valve comes on but the heat pump does not receive a run signal)
What are the signs of a faulty motorised valve?
Faulty Actuator: The actuator, which is the motor section mounted on top of the valve, is the most common cause of failure. If it has seized or is worn, your heating system may start showing intermittent or constant water flow errors or entire zones may stop heating altogether.
Seized Valve: If the brass valve itself has seized up and is difficult or impossible to move, it needs to be replaced.
Leaking Valve: A worn valve that is leaking will also need to be replaced to prevent further damage to your heating system.
Manual Override Issues: If the manual override lever is difficult to move or doesn’t work, it could indicate a problem with the valve or actuator.
Auxiliary Contact Issues: When the auxiliary contact in your motorized valve starts failing, this can lead to other components in your heating system not activating properly.
