Heating Monitoring: Why Transparency Is Key to Successful Optimisation

The debate around the heat transition often focuses on new heating technologies, refurbishment strategies and regulatory requirements. What is frequently overlooked, however, is a fundamental issue: in a large proportion of existing buildings, no one really knows how the installed heating systems actually operate. The housing sector is therefore facing a structural information gap. Without reliable data, efficiency potentials cannot be identified and decisions cannot be made on a sound basis. This is precisely where modern heating monitoring demonstrates its value – as the foundation for any meaningful digital or technical optimisation.

In practice, it repeatedly becomes clear how little is known about the actual condition of heating systems. Many systems have been running for years with undocumented settings, inappropriate heating curves or unnoticed faults. Operators often react only once tenants report comfort issues or energy consumption becomes conspicuously high. This reactive mode of operation is no longer fit for purpose – neither in the context of rising CO₂ costs nor in light of regulatory requirements that increasingly demand transparency and verifiable evidence.

A digital monitoring system addresses this challenge directly. It provides a continuous stream of data that makes it possible to observe how a system truly operates, identify malfunctions and trace changes over time. Data quality is crucial in this context. Only when temperature profiles, cycling behaviour and other relevant system parameters are captured with sufficient resolution and accuracy can robust conclusions be drawn. Experience shows that systematically analysed data reveals patterns that previously remained hidden – such as unnecessarily high temperature levels, incorrect responses to outdoor temperatures, or unstable interactions between control systems and valves.

Implementation in existing buildings is, however, more complex than it may appear at first glance. Residential buildings differ widely in their structure, and their heating systems reflect decades of technological development. Measurement points are often missing, documentation is incomplete, and even identical systems can behave very differently depending on building physics. A robust monitoring solution must be able to cope with this heterogeneity without requiring extensive, bespoke retrofitting for each individual system. It should deliver a reliable picture of system behaviour despite an imperfect starting point – and do so in a way that enables technical decision-makers to work with the data effectively.

Robust heating monitoring transforms isolated measurements into a consistent digital representation of the system state. It makes operational faults visible, enables data-driven optimisation, allows faults to be anticipated at an early stage and shifts technical decision-making from assumption to evidence – a prerequisite for efficient, compliant and economically sound system operation. Operators gain reliable insights into the energy performance of their building portfolios and can prioritise measures in a targeted manner. The documented data basis also supports ESG reporting and makes progress transparent and traceable.

Monitoring alone does not reduce energy consumption. However, it reveals where and why inefficiencies occur and indicates which measures are realistically effective. In this way, it forms the indispensable first step of any digital optimisation strategy: without transparency, all downstream optimisation remains a blind flight.

In the coming years, building operations will increasingly evolve towards data-driven models. Monitoring provides the starting point for this development. The next step is to determine how automated or adaptive optimisation measures can be implemented on the basis of these data. A pragmatic approach – particularly for existing buildings – is the use of smart thermostats that dynamically support hydraulic balancing and guide the system towards greater efficiency.

This is the focus of Part 2 of this series: how adaptive hydraulic balancing works via smart thermostats, the limitations and opportunities it presents in existing buildings, and why it represents a realistic, fast-acting step for the housing sector.