E8 on a Viessmann Vitotronic 200: Heat management: Electricity prices not set: "Economical" control strat-; If both are missing: Dual mode operation with fixed egy is not available. limits; Primary energy factors not set: "Ecological" control …
Short answer
On a Viessmann heat pump, E8 means: Heat management: Electricity prices not set: "Economical" control strat-; If both are missing: Dual mode operation with fixed egy is not available. limits; Primary energy factors not set: "Ecological" control …. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Heat management: Electricity prices not set: "Economical" control strat-; If both are missing: Dual mode operation with fixed egy is not available. limits; Primary energy factors not set: "Ecological" control ….
Part involved: Heat management.
When it shows: Electricity prices not set: "Economical" control strat-; If both are missing: Dual mode operation with fixed egy is not available. limits; Primary energy factors not set: "Ecological" control; If fuel type is not set: Dual mode operation with fixed strategy ….
Likely causes:
- Primary energy factors or electricity prices not specified.
- Incorrect fuel set.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: Not stated per code; Vitotronic messages remain until the cause is removed and are acknowledged with OK (6150133 p.82). Unremedied acknowledged faults are redisplayed the following day.
Manual reset: Acknowledge with OK on the programming unit (user level permitted per 5817913 p.56-57) after the cause is remedied.
What you can check
- Note the 2-character message code and message text shown on the Vitotronic 200 display (press OK for details) and give them to your heating contractor (operating instructions 5817913 p.56).
- You may acknowledge the message once with OK as described in the Vitotronic 200 operating instructions; if it reappears, do not keep acknowledging it - call your contractor.
What the engineer will check
- Set electricity prices and/or primary energy factors.
- Set fuel type.
Who to ask for: Viessmann-trained heat pump installer/service engineer.
Sources
- Service instructions Vitotronic 200 type WO1C heat pump control unit (air/water split & monobloc, brine/water) (6150133, 2023-07) ↗ · 6150133 VSA00004 · page 109 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026