BoilerFaultCodesYour smart thermostat has lost its wireless connection to the boiler, meaning you cannot control your heating remotely or via the wall unit.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: No connection
What causes this fault?
This fault occurs when the radio frequency link between your thermostat and the smart interface plugged into the boiler is interrupted. The most common reasons are physical obstructions like new furniture or thick walls blocking the signal, or electronic interference from other household devices.
DIY fix possible
Check that your home Wi-Fi router is switched on and working correctly.Ensure the Halo Smart Interface (the white box plugged into the boiler) has power and is not obstructed.Navigate to the 'Settings' menu on the Halo unit and select 'Pairing Mode' to reconnect the device to the interface.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like Red (Connectivity) — no call-out fees, no surprises.
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