With energy costs on the rise, accurate measurement and control of consumption are more important than ever. That’s why we leverage cutting-edge technology to make heat metering both effortless and precise.
An innovative heat meter must do more than just measure consumption – it needs to provide precision, reliability, and future-proof technology. ista's smart meters for heat or cooling deliver accurate results and feature state-of-the-art electronics, earning the trust of property managers and residents around the world. Whether you need a meter for new installations or for replacement within regulatory calibration periods, our high-quality, German-engineered products are the right solution.
Equipped with cutting-edge electronic measurement technology, the sensonic® 3 and sensonic® 3 calculator delivers precise, up-to-date readings for a transparent and easy-to-understand heating cost breakdown. Combining its well-known ease of installation with versatile application options and reliable measurement results, the sensonic® 3 stands out with its compact design and forward-thinking technology.
This heat meter features two external temperature sensors and can be mounted on all ista single-pipe connection components. Its compact dimensions ensure seamless installation, even under challenging conditions.
For replacing existing meters, the compact version with an integrated return temperature sensor is ideal. Thanks to the istameter principle and the proven 2-inch KOAX system, the replacement process is particularly quick and straightforward.
The integrated, interoperable wireless interface of the sensonic® 3 forms the foundation for digital heating cost accounting, making consumption data collection more efficient than ever.
For residents, smart metering means no need for an on-site meter reading – eliminating the hassle of appointments. For you, it enables seamless online property management, offering services like digital heating cost billing and automatic monthly consumption reports sent directly to residents.
Our heat metering system utilizes cutting-edge ultrasound technology to deliver precise heat consumption measurement. Equipped with an integrated wireless interface, it enables remote data transmission and reading, eliminating the need for manual meter readings.
The system automatically transmits data at pre-set intervals, ensuring timely and accurate consumption tracking. Designed for long-term reliability, the compact and robust sensonic® 3 features an exceptionally durable battery, making it ideal for continuous, maintenance-free operation.
Seamlessly integrating into existing building infrastructures, the device supports effortless energy management while ensuring compliance with European measurement regulations.
ista offers options for virtually every application – from compact meters for residential heat and cooling to combined meters for large apartment complexes and commercial properties.
With its high measurement accuracy, maintenance-free operation, and long service life, the ultego 3 smart helps minimize annual operating costs. Two compact product series with various combination options provide versatile applications for heat measurement.
The ultego 3 smart consists of an ultrasonic flow sensor, two permanently attached temperature sensors, and a calculation unit that determines energy consumption based on volume and temperature difference. Thanks to its integrated and interoperable wireless interface, the ultego 3 smart seamlessly integrates into the ista wireless system, enabling fully automated and digital consumption data collection.
Application areas
With a flow range: 0.6 - 60 m3/h the ultego 3 smart is ideal for various applications, including heating systems that use water as a heat transfer medium, transfer stations, and larger heating systems in apartment buildings.
Key advantages
• Precise, reliable and wear-free measurement
• Stable long-term performance
• Defined overload response
• Precise measurement of even the smallest flow rates
• Insensitive to dirt and reliable measurement
• Extremely low energy consumption
• Low pressure loss
• Fast, intelligent temperature measurement
• Can be installed horizontally or vertically (ultego III smart can also be installed overhead and with a removable calculator)
• Measuring range Flow 1:100 according to EN 1434, total 1:1000
• Tamper-proof through sealing
sensonic® calculator +ultrasonic flow sensor
Our combined heat meters consist of the sub-devices, a calculator, a flow sensor and a temperature sensor pair, and offer almost unlimited application possibilities.
Application areas
The sensonic® combined meter is the ideal solution for medium to large and complex residential units with six or more units, as well as commercial properties. It is perfectly suited for use as both a primary meter and a pre-distribution meter, ensuring precise and efficient energy measurement in diverse applications.
Heat meters measure heat consumption. Unlike heat cost allocators, they physically measure the nominal flow rate (heat quantity) of energy, which is why they are also referred to as heat quantity meters. The meter displays water consumption in cubic metres (m³) and heat consumption in kilowatt hours (kWh) or gigajoules (GJ).
Our modern measuring technology consists of:
Heat consumption is calculated based on the temperature difference between the supply and return pipes, with the resulting amount of heat expressed in kilowatt hours (kWh).
This calculation is performed continuously, allowing heat consumption to be accurately monitored during a billing period.
It is a physically exact unit of measurement. The display is on a roller counter or LCD display in kWh, mWh, G-Joule or G-Calorie.
Heat meters are installed in the pipe network, i.e. the water-carrying pipes, of a central heating system. These pipes transport the heated water produced by the central heating boiler or heat pump to the various heat emission systems, such as radiators, underfloor heating or convectors. The heat meter accurately measures heat consumption by recording the temperature difference and the flow rate of the water in the pipe network. This allows for precise recording of heat consumption.
The costs of the heat meter itself cannot usually be passed on separately to tenants as service costs. According to an important ruling by the Supreme Court (2022), heating installations such as heat meters and thermal energy storage systems are considered an integral part of the property (immovable appurtenance). As a result, investment and maintenance costs for these installations must be charged via the basic rent and may not be charged to the tenant as separate service costs.
If several homes or units are connected to a central hot water system, the Heat Act stipulates that consumption must be measured for each home. This can be done using a heat meter connected to the home.
A heat meter is required as soon as heat or hot tap water is supplied via a communal installation. This allows consumption to be divided fairly between households. Only if individual metering is technically impossible or financially unreasonable may an alternative such as heat cost allocators be used.
Heat meters have a statutory calibration period (usually 10 years). After that, they must be replaced or recalibrated. In addition, new meters must now be remotely readable. Older meters that are not must be replaced by 2027 at the latest.
