Warranties, including extended warranties, can be conditional. If they are conditional, any special requirements must be reasonable and justifyable. While it is a different product, it is worth reading this thread as it may provide some useful information to you:
If the Brivis Ducted Heater needs the replacement of (what appears to be) consumables to be in good working order, then the servicing requirement would be reasonable.
Using a different example, when buying a car, extended warranties are conditional. They require the owner to maintain the car in accordance with the vehicle’s service manual and for Mitsubishi, to have one’s vehicle serviced at their service centres. The manual also includes replacement of consumables such as oils, oil filters, air filters etc. Servicing is done to maintain the vehicle in good working order and to prolong it’s serviceable life.
