BoilerFaultCodesWhat the manual says
Manufacturer manual3-way valve
What causes this fault?
This fault occurs when the mechanical component that directs hot water between your taps and radiators becomes jammed or fails to move. It is often caused by a build-up of debris and sludge from within the heating system or a simple failure of the small motor that pushes the valve into position.
This issue is frequently noticed in autumn when homeowners turn their heating back on for the first time, as the valve may have seized after months of only providing hot water.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like T.02: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 110 fault codes on the ecoTEC plus 938 VUI GB 386/5-5 A
Seeing a different code? Every code this model can display, in one place.
Related guides you might find useful
No hot water but heating works
Almost always a stuck diverter valve on a combi.
Read →Radiator not heating up
One cold radiator is usually a stuck valve pin or trapped air.
Read →Hot water works but heating does not
On a combi it is usually the diverter valve. On a system boiler, the motorised valve.
Read →