BoilerFaultCodesYour boiler is displaying a status reading for the warm start sensor temperature rather than an error, which is part of the system's normal operational monitoring.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Current temperature for warm stat sensor
What causes this fault?
This code appears because the boiler is communicating its current internal temperature reading for the warm start function rather than an actual error. It physically occurs when the system is monitoring the thermal store to ensure instant hot water is available. You are seeing a live status update of the sensor's data, which means the internal computer is working exactly as intended.
DIY fix possible
Press the 'back' or 'menu' button to return to the main pressure or temperature displayMonitor the boiler for any actual fault codes starting with 'F'Ensure the warm start function (if desired) is enabled or disabled via the control knob
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 D.4 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.