Worcester Bosch · Greenstar i System ErP
D4 341 boiler fault code
Greenstar i System ErP
What D4 341 means
Primary flow temperatures rising too fast.
Gas Safe engineer: If the pressure is not below 1 bar, or the code returns, contact a Gas Safe registered engineer.
If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.
Safe check
Check the pressure gauge. If it reads below 1 bar, top up to about 1.5 bar through the filling loop shown by your installer and the user guide, without removing the casing, then press Reset once. If it is not below 1 bar, or the code returns, contact a Gas Safe registered engineer.
When to contact an engineer
If the pressure is not below 1 bar, or the code returns, contact a Gas Safe registered engineer.
Source and provenance
- Greenstar i System ErP Installation, commissioning & servicing instructions 6 720 806 945 (2015/07) · §8.1.2 Error codes, Table 49, printed p. 69
installation, commissioning & servicing instructions
2015/07
- Greenstar i System ErP User Instructions 6 720 806 947 (2015/03) · §4 System pressure, printed p. 18
user instructions
2015/03
After: Repressurise the boiler