The Drayton TRV4 Classic Integral Sensing Head (MPN 07 25 006) is a standalone replacement or retrofit thermostatic sensing head for any TRV4-compatible valve body. Featuring Drayton's liquid-filled chrome sensing element with 0.22 mm/°C sensitivity, it achieves the TELL Class I energy efficiency rating — the highest under the European valve manufacturers certification scheme — and is approved to BS EN 215. Sold separately from the valve body, it allows head-only upgrades or replacements without changing the pipework. The white and chrome classic finish is the same as the full TRV4 Classic range, Britain's best-selling TRV since 1993.
Class I
Energy Efficiency
0.22mm/°C
Sensor Sensitivity
Compatibility
This sensing head fits TRV4 valve bodies only. It is not compatible with TRV3 bodies. For retrofitting onto older TRV3 bodies, use the dedicated TRV4 conversion head. The head-to-body fixing is infinitely adjustable for orientation.
Head Orientation
The integral head can be fitted vertically or horizontally, allowing installation in positions where a standard upright head would obstruct furniture or pipework.
Key Features
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Liquid-Filled Sensor
The liquid-filled sensing element delivers 0.22 mm/°C sensitivity — faster and more accurate room temperature control than wax-element heads, contributing to the Class I efficiency rating.
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TELL Class I Rated
TELL Class I certification evaluates response speed to temperature change, accuracy at maintaining setpoint, and performance stability under varying water temperature and system pressure.
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Range-Limiting Function
The built-in range-limiting collar allows the installer to restrict the maximum temperature setting, preventing occupant over-adjustment — useful in commercial, HMO, and social housing installations.
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Frost Protection
The * setting (below 8°C) closes the valve to protect the property from frost damage even when the boiler is in reduced-hours operation.
Technical Specifications
| MPN |
07 25 006 |
| Type |
Integral Standard Sensing Head |
| Finish |
Classic White / Chrome |
| Setting Range |
Approx. 10°C – 30°C (settings 1–5 + MAX) |
| Frost Protection Setting |
Below 8°C (marked *) |
| Max Sensor Temperature |
50°C |
| Sensor Sensitivity |
0.22 mm/°C |
| Hysteresis |
0.4 K |
| Response Time |
20 minutes |
| Water Temperature Influence |
0.8 K |
| Differential Pressure Influence |
0.15 K |
| Control Accuracy |
0.6 K |
| Standard |
BS EN 215 / TELL Class I / Keymark (valid to 31.03.2029) |
| Manufacturer |
Drayton by Schneider Electric |
Frequently Asked Questions
Will this head fit my existing TRV valve body?
The TRV4 integral head is designed for TRV4 valve bodies. It is not compatible with TRV3 bodies. TRV4 bodies have been produced since 1993 and feature a slimline profile. The fixing is infinitely adjustable, allowing fine-tuning of the head orientation on the body.
Can the head be fitted horizontally?
Yes. The TRV4 integral head can be installed in vertical or horizontal orientation, making it suitable for corner radiators and positions where vertical clearance is limited.
What does the range-limiting feature do?
The range-limiting ring inside the dial collar restricts the maximum temperature the occupant can set. This is particularly useful in rental properties, commercial buildings, and social housing where overheating and energy waste need to be controlled.
What is the difference between this head and the remote sensing head?
The integral head (07 25 006) senses air temperature at the valve position. The remote head (07 25 007 / 07 25 008) uses a 2m stainless steel capillary to position the sensing bulb at a more representative room location — ideal where the valve is obscured by furniture or curtains.
Does this head need electrical power?
No. The TRV4 is a self-operating thermostatic valve — the liquid-filled sensor expands and contracts with temperature changes, mechanically controlling the valve pin without any external power source.
