E9 checks
| Step | Check | If yes | If no / next |
|---|---|---|---|
| 1 | Fully pumped sealed system? | Go to step 3. | Go to step 2. |
| 2 | Open-vented: enough water in the F&E tank? | Go to step 4. | Top up, vent, reset for 3 seconds. |
| 3 | Sealed system pressure between 1 and 2 bar? | Go to step 4. | Top up, vent, reset. |
| 4 | Pump seized? | Free the pump or replace it, refill/vent, reset. | Go to step 5. |
| 5 | Lead disconnected from flue and/or CH flow safety temperature limiter? | Reconnect, reset. | Continue limiter continuity checks, fuse SI 3, then PCB. |
Gas work stays with a Gas Safe registered engineer. These steps are guidance from the manufacturer sequence, not a substitute for the handbook.