Worcester Bosch [2970] fault codewhat it means and how to fix it

2970, pressure drop in heating system too rapid, is a blocking fault on the Greenstar 8000 Life, 8000 Style and 8000+ combi and system boilers and on the 4000 combi, and Worcester's own description of it is too many unexpected pressure drops within a short time period. The boiler is watching its pressure sensor continuously, and a system that keeps losing pressure faster than a sealed system should is either leaking or being interfered with.

Worcester's remedy points first at the second. The 8000 range can be fitted with the Greenstar Intelligent Filling System, an accessory that tops the system up automatically to a programmed pressure and logs 2968, refilling system pressure, each time it does; the cause code can appear, the manual says, if the system is pressurised and the intelligent filling loop activated and then the system vented — the fill raises the pressure, the venting drops it sharply, and the boiler counts that as an unexpected loss. The instruction to the engineer is to switch off the intelligent fill in the system menu, re-pressurise manually and vent the system, ensure the correct pressure, and if the code does not clear, power the appliance off.

There is a companion code, 2969, maximum number of refills reached, which is the filling system declining to keep topping up a system that will not hold water. Without the accessory the meaning is plainer: water is leaving, and quickly. The householder's job is to note how fast the pressure falls and where any water is showing; the engineer's is to decide between a venting artefact and a real leak.