Do unvented cylinders need annual servicing?
Yes — unvented cylinders must be serviced annually by a G3-qualified engineer to remain safe, insured and compliant with building regulations.
Annual Servicing Is a Requirement
Under Building Regulations (Part G3), unvented hot water cylinders must be installed and serviced by a G3-qualified engineer. Annual servicing checks:
- Temperature and pressure relief valves
- Expansion vessel pressure
- Tundish and discharge pipework
- Immersion heater and thermostat
- Signs of corrosion or leaks
Skipping servicing can void your cylinder's warranty and your home insurance in the event of a fault. RARE engineers are G3 qualified and service all major cylinder brands, including as part of our PPM membership plans.
Reviewed by RARE Plumbing London Engineering Team — Gas Safe registered engineers serving prime London since 2013.
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