Intelligent management of hydraulic heating today involves the installation of thermostatic heads, capable of regulating the temperature room by room and providing real thermal comfort while optimizing consumption.
But did you know that there are many different sizes of fittings for radiator valves?
Let's discover together the essentials you need to know about adapters for thermostatic valve heads (TRV)!
What is a TRV?
TRV, for “Thermostatic Radiator Valve”, refers to the thermostatic radiator valve, composed of two main elements:
- The valve body : connected to the radiator and the hot water network, it contains the mechanism which regulates the flow.
- The thermostatic head : the visible, adjustable part, equipped with a sensor that measures the ambient temperature. Depending on the setting and the measured temperature, it opens or closes the valve, thus modulating the circulation of water and therefore the heat released by the radiator.
It is important to note that not all radiators are necessarily equipped with a thermostatic valve body: some still have a manual valve, which will need to be replaced to install a thermostatic head.
The main formats of fittings for TRV
Depending on the radiator model and valve brand, different threads exist. Here are the most common formats found in France and Europe:
1. M30 x 1.5 – The European standard
This is the most common thread format. It is used in most recent installations and many well-known brands (Danfoss, Honeywell, Oventrop, etc.).
- Dimensions: 30mm diameter, 1.5mm screw pitch.
- Compatibility: Most modern thermostatic valves.
2. M28 x 1.5
Less common than the M30 standard, this format is used by certain brands such as Giacomini or older models.
- Dimensions: 28mm diameter, 1.5mm screw pitch.
3. Danfoss RA / RA-N
Danfoss offers a specific format for its RA series, different from the usual standards.
- Compatibility: Installing a standard thermostatic head often requires a Danfoss RA adapter.
4. Interlocking systems (Heimeier/TA)
Some brands like Heimeier or TA use snap-on (fitting) heads and not threaded ones.
- Compatibility: Specific adapters required for installation of universal heads.
5. Other specific formats
Some brands (Caleffi, Giacomini, etc.) offer proprietary threads. Specific adapters are generally available for these references.
6. Usefulness of adapters
In case of incompatibility between the thermostatic head and the valve, adapters are available to convert the thread or the mounting method. This ensures installation on most radiators, including older or “exotic” radiators.
Summary of the most common formats:
- M30 x 1.5 (European standard)
- M28 x 1.5 (Giacomini, others)
- Danfoss RA (Danfoss specific)
- Interlocking systems (Heimeier, TA, etc.)
To choose the correct adapter, always check the existing thread or consult your installation documentation.
The adapters supplied with the TRV NodOn
The NodOn Zigbee Thermostatic Valve Head is directly compatible with the M30 x 1.5 standard (the most common).
To ensure installation on the vast majority of equipment, it also comes with three adapters: Danfoss RA, RAV and RAVL, thus covering more than 80% of existing installations. This allows for quick installation without worrying about the brand or model of valve installed.
In some specific cases (e.g. Caleffi, Giacomini or other older models), it may be necessary to use an additional adapter, available from specialist retailers.
In conclusion
Thanks to the variety of adapters available, the installation of a thermostatic head, connected or not, is possible on almost all radiators on the market.
Before any order or installation, take care to identify the format of your existing valve: a simple check which guarantees you easy, efficient and durable installation!
Need advice or additional information? Don't hesitate to contact the NodOn team !
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