BoilerFaultCodesWhat the manual says
Manufacturer manualCylinder thermistor fault
From this model's manual
Verified against the Glow Worm/Glow Worm Ultracom 35 Store 4701915 installation & service manual.
What causes this fault?
This fault occurs when the boiler can no longer detect a signal from the sensor that monitors the temperature of your hot water tank. The most common reasons are a breakdown of the internal sensor components or a loose connection in the wiring that links the sensor to the boiler's main control board.
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.
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Related fault codes
All 70 fault codes on the Ultracom 35 Store
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