Calorifier (Hot Water Storage Vessel) Maintenance Checklist
Protect against legionella and prevent vessel failure with calorifier checks covering stored temperature monitoring, sacrificial anode condition, thermostat calibration, and descaling schedules.
What is a calorifier maintenance checklist?
A calorifier (hot water storage vessel) maintenance checklist is a structured list of the 11 preventive maintenance tasks — covering visual, functional, safety and record-keeping checks — that keep a calorifier (hot water storage vessel) running safely and reliably. It groups routine checks by frequency, from daily inspections to annual servicing, so FM teams and building engineers can plan and evidence preventive maintenance.
Core calorifier checks
- Inspect sacrificial anode condition (where fitted) and replace if >50% consumed
- Check stored water temperature is above 60°C throughout the vessel
- Test the temperature and pressure relief valve operates freely
- Record stored temperature, outlet temperatures, and any maintenance performed
What is a calorifier (hot water storage vessel)?
A calorifier is a hot water storage vessel heated by an internal coil connected to a primary heating circuit. It stores domestic hot water at temperatures required for both occupant use and legionella control. Calorifiers are common in commercial buildings, hotels, hospitals, and any facility with significant hot water demand. Maintenance focuses on temperature management, water hygiene, and the condition of the vessel and its internal components.
Typical Calorifier maintenance checklist
A practical starting point for planned preventive maintenance. Always refer to the manufacturer's O&M manual and site-specific requirements.
Visual Checks
- Inspect sacrificial anode condition (where fitted) and replace if >50% consumed
- Inspect insulation jacket for damage or wet patches indicating leaks
- Inspect pipework connections for leaks or corrosion
Functional Checks
- Check stored water temperature is above 60°C throughout the vessel
- Verify water temperature at the nearest outlet reaches 50°C within one minute
- Check primary coil flow and return temperatures
- Check thermostat and aquastat calibration
- Check the drain valve operates and allow a brief flush to check water clarity
Safety Checks
- Test the temperature and pressure relief valve operates freely
- Verify legionella temperature monitoring is in place
Record Keeping
- Record stored temperature, outlet temperatures, and any maintenance performed
Typical maintenance frequency
Suggested intervals for calorifier (hot water storage vessel) maintenance. Actual frequencies should follow manufacturer guidance and site-specific risk assessments.
Monthly
- •Record stored water and outlet temperatures
- •Visual inspection for leaks
Quarterly
- •Test T&P relief valve
- •Check anode condition (annual replacement cycle)
Annually
- •Full internal inspection where possible
- •Descale if hardness levels warrant
- •Replace sacrificial anode
- •Review legionella risk assessment
- •Check thermostat calibration
Common faults and issues
Issues to be aware of when maintaining calorifier (hot water storage vessel) equipment.
Safety and compliance notes
Key safety considerations for calorifier (hot water storage vessel) maintenance. This is general guidance only — always follow OEM instructions, statutory requirements, and your organisation's safe systems of work.
Managing Calorifier documentation with PM Assist
PM Assist helps FM and building operations teams search their O&M manuals and building drawings in seconds. Upload your calorifier (hot water storage vessel) documentation and ask questions like “What temperature should the system be set to?” or “What safety checks are required annually?” — and get source-cited answers instantly.
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