DN25 Ultrasonic Heat Meters (1”)

DN25 is used where the flow rate of a DN20 meter is not sufficient, such as in duplex apartments, large dwelling units and small commercial spaces. This page lists DN25 models from five brands.

DN25: Check the Body Length

DN25 corresponds to a 1-inch pipe size, and the models on our site have a 1 1/4” connection thread. At this size there is a clear difference between brands: the technical data for the Honeywell and Novus Digitermo DN25 list a nominal flow rate (Qn) of 3.5 m³/h and a body length of 160 mm, while the Minol Zenner C5 IUF DN25 lists a nominal flow rate of 6 m³/h and a body length of 260 mm. The manufacturer ZENNER also offers 150 mm and 260 mm body lengths for this size. When replacing a meter, first check the length of the old meter and the qp value on its label: a 260 mm meter will not fit into a 160 mm gap, and in the opposite case an extension piece is needed to fill the gap.

Models in This Size

• Novus Digitermo DTL-DN25 – Qn 3.5 m³/h, 160 mm, heating/cooling
• Minol Zenner C5 IUF DN25 – Qn 6 m³/h, 260 mm, M-Bus
• Calmet PM02-DN25 – built-in wired M-Bus
• CEM CM-HR DN25 – built-in wired M-Bus
• Honeywell DN25 – Qn 3.5 m³/h, 160 mm, heating only

Other sizes: DN15 · DN20 · DN32 · DN40 · Large diameter (DN50–DN300) · DN20 mechanical

Frequently Asked Questions

How many inches is a DN25 heat meter?

DN25 corresponds to a 1-inch pipe size; the models on our site have a 1 1/4” connection thread.

What is the body length of a DN25 heat meter?

It depends on the model: 160 mm for the Honeywell and Novus Digitermo DN25 models on our site and 260 mm for the Minol Zenner C5 IUF DN25. Measure the length of the old meter before replacing it.