A: In most cases, no . The boiler will lock out and stop both heating and hot water for safety.
When a heating engineer arrives, they will use specialized diagnostic tools to isolate and fix the exact component causing the D6 error.
Using a multimeter, the technician will test the continuity of the air pressure switch. If the switch shows continuity (a closed circuit) while the fan is disconnected, the switch is broken and must be replaced.