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c) Information on the range
• The transmission power is less than 10 mW, much below that of a mobile phone which may
have a transmission power 200 times as great. Adverse effects on sensitive people and
animals are not to be expected.
• The wireless radiator thermostat system uses the 868 MHz range, which is also used by
other radio services. Therefore devices that operate on the same or neighbouring frequen-
cies may restrict both its operation and its range.
• The specified range of up to 100 m (to the ‘FHT8V’ valve operating mechanism) or up to
300 m (to the ‘FHZ1000’) is the free-field range, which means the range with visual contact
between the transmitter and receiver. In practice, however, walls, ceilings, etc. between the
transmitter and the receiver may affect and reduce the range.
Other causes of reduced ranges:
• All types of high-frequency interference
• Any buildings or vegetation
• Conductive metal parts that are located near the devices or within or near their transmission
path, for example, radiators, metallised insulation glass windows, reinforced concrete
ceilings, etc.
• Influence on the radiation pattern of antennas due to the distance from the transmitter or
receiver to conductive surfaces or objects (also to human bodies or the ground)
• Broadband interference in urban areas that reduces the signal-to-noise ratio; the signal is
no longer recognised due to this ‘noise’
• Interference radiation resulting from insufficiently shielded electronic devices, for example,
operating computers or similar
