Identify the warning, do not guess the part.
If you Protherm Puma Condens AS/2 show a code, copy the complete message and check the model. Here you will find the warnings from its manual and what information to provide for a review. A code guides: it does not confirm by itself which spare part is needed.
Models and version of the manual
18/24 MKV-AS/2 and 24/28 MKV-AS/2. The consulted edition identifies the models MKV-AS/2. Check the full designation before using the meaning of a code.
Consulted edition: 8000034432_00 · 07/05/2025 · manufacturer's manualThe control options, accessories, and versions may limit which notifications appear in each installation.
Locate the code on your screen.
These accesses lead to their entry in the table. They are not a classification of the most common faults: the manual does not provide incidence statistics.
- F.22
Installation pressure too low
- F.28
Failed ignition
- F.29
Ignition and control error during operation, the flame is off.
- F.75
Pump fault/water shortage
What to do without opening the boiler
- Note what you see.
Complete code, message, and pressure displayed by the equipment. Indicate whether it occurs when opening hot water, requesting heating, or in both cases.
- Identify the device.
Take a photo of the screen and the identification accessible without disassembling anything. Brand, model, and version help avoid confusing tables from different ranges.
- Describe how it started.
Determine whether the fault is continuous or intermittent and if there was a supply interruption or a recent intervention. If it reappears after a reset allowed by the user manual, do not chain resets.
Do not open the casing or manipulate gas, wiring, combustion, or flue gas outlet. If you smell gas, avoid flames and switches, leave the area, and notify the distributor's emergency service from a safe location; in case of immediate danger, call 112.
Documented codes table
The meaning of the warning is provided, not the repair operations reserved for qualified personnel. When the manufacturer groups several codes, the grouping is maintained; it is not interpreted as a range of numbers.
| Code | What does · source indicate? |
|---|---|
| F.00 | Flow temperature sensor interruption PDF |
| F.01 | Return temperature sensor interruption PDF |
| F.10 | Short circuit of the supply temperature sensor. PDF |
| F.11 | Return temperature sensor short circuit PDF |
| F.13 | Short circuit in the accumulator temperature sensor. PDF |
| F.20 | Safety disconnection of the temperature limiter PDF |
| F.22 | Installation pressure too low PDF |
| F.23 | Safety shutdown: excessive temperature variation PDF |
| F.24 | Safety disconnection, temperature rise too fast PDF |
| F.25 | Safety disconnection: flue gas temperature very high PDF |
| F.27 | Safety disconnection, flame simulation PDF |
| F.28 | Failed ignition PDF |
| F.29 | Ignition and control error during operation, the flame is off. PDF |
| F.32 | Fault: fan PDF |
| F.33 | Excessive pressure losses in the air intake/exhaust gas system PDF |
| F.46 | Short circuit of the cold water sensor PDF |
| F.49 | Fault: eBUS PDF |
| F.61 | Fuel control valve error PDF |
| F.62 | Error, delayed disconnection of the fuel control valve PDF |
| F.63 | Fault: EEPROM PDF |
| F.64 | Fault, electronics/temperature sensor PDF |
| F.65 | Electronic temperature fault PDF |
| F.67 | Fault: electronics/flame PDF |
| F.68 | Fault: unstable flame signal PDF |
| F.70 | Invalid device identification (DSN: "Device Specific Number") PDF |
| F.71 | Fault in the supply temperature sensor PDF |
| F.72 | Fault, return temperature sensor PDF |
| F.73 | Water pressure sensor signal out of range (too low) PDF |
| F.74 | Water pressure sensor signal out of range (too high) PDF |
| F.75 | Pump fault/water shortage PDF |
| F.76 | Fault, thermal device lock PDF |
| F.77 | Fault, anti-return flap for combustion gases/condensate pump PDF |
| F.78 | Interruption of the domestic hot water outlet temperature sensor with external control PDF |
| F.83 | NTC temperature fluctuation fault PDF |
| F.84 | The NTC temperature difference is unbelievable. PDF |
| F.85 | Incorrectly mounted (swapped) supply and return temperature sensors PDF |
| F.86 | External safety disconnection PDF |
| F.87 | Ignition electrode fault PDF |
| F.88 | Fault in the gas valve PDF |
| F.89 | Fault in the pump PDF |
| F.97 | Main PCB self-check fault PDF |
Is there a problem, but no fault code appears?
The absence of a warning does not rule out a fault. For a boiler that does not heat, does not deliver hot water, loses pressure, or operates intermittently, describe the symptom and the moment it occurs. Do not assume that the PCB, the pump, or a sensor is faulty without checking the equipment and the installation.
Request a review of the boiler. · Consult maintenance
Before requesting a repair
Does the code identify the spare part I need to buy?
No. A single warning can have multiple causes. The spare part reference requires identifying the appliance and confirming the fault; the code or a generic photograph is not sufficient.
Can it be reset again if the fault returns?
It is not advisable to chain resets. Follow only what is outlined for the user in your version's manual. A persistent or recurring lockout requires inspection.
When does it make sense to compare a new boiler?
When you have a diagnosis and a budget, compare repair, availability of the spare part, and replacement according to your installation. An isolated fault code does not justify changing the equipment.
Models of this guide in the catalog
See new boilers · Consult installation or replacement
The technical sheet of each product provides information on its price and availability. Installation is quoted separately depending on the case.
Documentation and other guides
Official manual of Protherm Puma Condens AS/2 · 8000034432_00 · 07/05/2025. The page references in the table correspond to the PDF viewer, whose numbering may differ from the printed version.
Consult fault guides by brand and model. · Return to the blog