5 critical mistakes when positioning an R290 heat pump – and how to avoid them

Important notice
Installation, positioning and commissioning of R290 heat pumps must only be carried out by qualified and trained professionals. Propane (R290) is a flammable A3 refrigerant. Improper work can lead to serious safety risks, system failures and liability issues.

Why this topic matters now

R290 (propane) is the future-proof, environmentally friendly refrigerant in heat pump technology – natural, efficient and sustainable. At the same time, its flammability requires the highest level of care in planning and installation. In practice, the same five siting errors repeatedly cause safety issues, performance losses or failed inspections. This article shows installers the five most common placement mistakes – and how to avoid them safely.

1. Safety clearances are too small

R290 is heavier than air and can accumulate near the ground in case of a leak. Therefore, clear safety distances apply:

• At least 1 m distance to windows, doors, ventilation openings and light wells
• At least 0.5 m free space above the top of the unit
• No sources of ignition (barbecue, patio heater, sockets) within a radius of 1 m

If these zones are not respected, propane can migrate into indoor areas – with potentially dangerous consequences.

Practical tip: Plan at least 3 m distance to walkways or neighbouring properties to reduce draughts and noise.

2. Incorrect installation height and condensate management

Many installations fail at a basic point: the foundation. An R290 heat pump must not be installed in pits, depressions or basement light wells, as propane can accumulate there in case of a leak.

• Use a level, frost-free foundation (concrete slab or steel frame)
• Maintain at least 30 cm distance to ground level for the siphon and frost protection
• Discharge condensate via an insulated DN 50 pipe with a slope of 1:100

Field tip: Install trace heating on the condensate line to prevent freezing and ice build-up.

3. Missing equipotential bonding and grounding

Electrical safety is fundamental: according to DIN VDE 0100-540, all conductive parts (metal frame, piping, housing) must be connected to the equipotential bonding system. Without proper grounding, dangerous touch voltages or corrosion can occur.

• Use a deep earth electrode according to DIN 18014
• Include all metal pipes and flexible connections in the bonding system
• Install surge protection devices (SPD) in accordance with DIN VDE 0100-534

Technician’s tip: A frequent source of error is unbonded stainless-steel flexible hoses. Always check the connection to the equipotential bonding bar before commissioning.

4. Airflow requirements are underestimated

R290 heat pumps require unobstructed air circulation. If the unit is placed too close to obstacles, efficiency can drop significantly.

• At least 30 cm distance to the wall behind the unit
• At least 50 cm free space on the sides
• 2–3 m discharge distance to walkways or neighbouring properties
• No installation in tight corners – this causes air short circuits and longer defrost cycles

Planning tip: Choose an open but wind-protected location that allows service access (approx. 1 m free space behind and beside the unit). This ensures stable performance even in winter conditions.

5. Missing labelling and documentation

Every R290 heat pump must be clearly labelled in accordance with IEC 60335-2-40 (2022):

• Nameplate with refrigerant (R290), charge quantity and operating pressure
• Hazard symbols for highly flammable gases
• For charge quantities > 5 kg: additional safety signage (e.g. “No open flames”)

In addition, the operator must receive the operating manual, CE declaration of conformity, leak test reports and maintenance records.

Checklist:

• Nameplate present and legible?
• Service label for propane clearly visible?
• System logbook completely filled in?

Without this documentation, the system cannot be formally accepted – and fines may be imposed in the event of damage.

Conclusion: Safety and efficiency start with correct positioning

By avoiding these five mistakes, you protect not only the system itself, but also people and buildings. R290 heat pumps are highly efficient and environmentally friendly – provided they are professionally planned, installed and documented.

Final tip: Contact us for individual support on R290 heat pumps, safe siting and matching accessory solutions.