Heating failure in winter: Minimum temperature, obligations and immediate measures for landlords

Heating failure in winter: What landlords now need to know about the minimum temperature obligation

If the heating breaks down in winter, there is not only the threat of dissatisfied tenants, but also legal and financial risks. Landlords are obliged to provide sufficient heating during the heating period. Minimum temperature in the rented premises and to rectify defects immediately. This guide explains which temperatures are considered normal, how quickly you need to react, which temporary solutions are acceptable and how you can avoid rent reductions, consequential damage and reputational risks.

Minimum temperatures: What values apply in practice?

The obligation to maintain a minimum temperature results from the Fitness for purpose of the rental object (§ 535 BGB) and the case law on the heating obligation. The recognised standard values in winter are

• Living and recreation rooms: approx. 20-22 °C during the day
• Bedrooms: approx. 18 °C at night
• Baths: approx. 21-23 °C at peak utilisation

The temperature counts for the assessment in the centre of the room, about 1 m above the floor, not directly on external walls or at the window. The heating times usually include the daytime hours; at night, the temperature may temporarily be slightly lower, but not to a level that makes use unacceptable.

Obligations of the landlord in the event of heating failure

A heating failure is a Significant defect. Landlords must immediately Take action: organise fault acceptance, commission a specialist company and inform the tenants about the next steps. If there are delays, you risk Rent reductions from the occurrence of the defect. The amount depends on the severity and duration; in the event of total failure in winter, reductions can be considerable.

• Response time: During the heating period, an intervention within 24 hours is considered appropriate, in the event of severe frost as quickly as possible (emergency service).
• Communication: Provide transparent information: Cause, expected rectification time, interim solutions, contact person.
• Replacement heating: If the duration is expected to be several hours Mobile heaters an effective interim solution.

Typical mistakes - and how to avoid them

Replacement heating, costs and rent reduction: pragmatic calculations

Mobile electric heaters are generally accepted as a temporary solution if they bring rooms up to the required temperatures. Important: Appliances with tilt and overheating protection, adequate circuit protection, user instruction. Electricity costs should be proactive in order to avoid conflicts.

Calculation example (assumption): Warm rent € 1,200 / month ≈ € 40 / day. In the event of total heating failure on cold days Rent reductions of 20-50 % conceivable (depending on the individual case). For 30 % and 3 days, that would be 3 × 12 € = 36 €. Two borrowed electric heaters, for example, cost €40-60 per week, plus electricity costs (approx. 2 kW × 6 h × €0.35/kWh ≈ €4.20 per appliance per day). Conclusion: Act quickly and provide a replacement is usually more favourable economically than a longer reduction phase.

Practical steps in an emergency

• Step 1: Record fault message, query temperatures, request photo/video if necessary.
• Step 2: Commission emergency service heating engineer; communicate ETA.
• Step 3: Replacement heater confirm in writing that you will pay the electricity costs.
• Step 4: Prevent moisture damage: recommend regular shock ventilation, check critical zones (exterior walls, window reveals).
• Step 5: After repair: function test, temperature measurement, final notification to tenant.

Communication and document management

A professional approach reduces annoyance and demonstrates your endeavours. Use a Standardised information sheet for tenants (What happened? How long? Contact person? Replacement measures?). Keep Order confirmations, installer reports, photos of the thermometer display and tenant communication in an organised manner. This helps in the event of disputes about reductions or compensation.

Prevention: maintenance, modernisation and monitoring

Scheduled Maintenance before the heating period (burner, pumps, expansion vessel, ventilation) minimises failures. Hydraulic balancing and clean control technology ensure that target temperatures are achieved even on cold days. Remote monitoring (e.g. fault messages via gateway) makes problems visible before tenants freeze. For old systems, check whether a Partial modernisation (high-efficiency pump, control, thermal insulation of pipes) increases operational reliability and reduces energy costs.

Also important is the User informationcorrect ventilation and heating, thermostat operation, keeping radiators clear. A short, easy-to-understand guide in the house folder avoids misunderstandings and unnecessary service calls.