Worcester Bosch [2948] fault codewhat it means and how to fix it

The 8000 generation splits a failure to establish a flame into stages, and 2948, 2949 and 2950 are the blocking versions — the boiler has not locked out, it has purged and will start again. 2948 is no flame signal with low output; Worcester's note says the burner starts automatically after purging and that strong winds can cause it, and the checks are the CO2 settings if the fault occurs repeatedly, the flue integrity and the flue terminal.

2949 is the same at high output, where the note adds flue gas recirculation and the checks extend to the burner and heat exchanger gaskets, the inner flue gaskets, and the gas pressure while burning at full load, dropping low. 2950 is no flame signal following the starting procedure, with the CO2 settings, the gaskets and the gas pressure again. The Greenstar 2000 repeats the low and high output pair as 2953 and 2954. Read together they describe a burner that is lighting but not holding a stable flame, and the three suspects are the same each time: the combustion set-up, the flue and the gas supply under load.

If the events keep coming the boiler escalates to 2951, loss of flame too many times, which is a lockout. So this page is the early warning. A single 2948 on a wild night is the boiler coping with wind at the terminal; a run of them in still weather means the combustion needs checking with an analyser, which is an engineer's job and one the Building Regulations require to be recorded. The householder's part is to notice the pattern — weather, time of day, whether the hot tap was running — and pass it on.