Degasser (Deaerator) Maintenance Checklist
A maintenance checklist for system degassers and deaerators covering valve inspection, venting checks, and water quality monitoring for closed-circuit heating and cooling systems.
What is a degasser maintenance checklist?
A degasser (deaerator) maintenance checklist is a structured list of the 9 preventive maintenance tasks — covering visual, functional, cleaning, safety and record-keeping checks — that keep a degasser (deaerator) 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 degasser checks
- Inspect the vacuum chamber for signs of corrosion or damage
- Verify the degasser is cycling correctly and venting gases
- Clean strainer upstream of the degasser if fitted
- Test water quality
- Record operational cycles, water quality results, and any faults
What is a degasser (deaerator)?
A degasser removes dissolved air and gases from closed heating or cooling water circuits. Dissolved gases cause corrosion, reduce heat transfer efficiency, and create noise in pipework and radiators. Degassers work by reducing the water pressure in a chamber, allowing dissolved gases to come out of solution and be vented. They are critical to maintaining water quality and system longevity in commercial heating and cooling installations.
This checklist is one of 25 in our plumbing and water system maintenance checklists, covering pressurisation units, booster sets, storage tanks, TMVs and water treatment — pressure, hygiene and legionella control.
Typical Degasser 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 the vacuum chamber for signs of corrosion or damage
- Check all connections and valves for leaks
Functional Checks
- Verify the degasser is cycling correctly and venting gases
- Check the air vent valve operates freely and is not blocked
- Verify system water pressure remains stable during degasser operation
- Confirm electrical supply and control signals are functioning
Cleaning & Housekeeping
- Clean strainer upstream of the degasser if fitted
Safety Checks
- Test water quality — dissolved oxygen, pH, and inhibitor levels
Record Keeping
- Record operational cycles, water quality results, and any faults
Download the free Degasser maintenance checklist PDF
Get all 9 tasks as a printable PDF — free, no signup needed. Keep a copy in the plant room, attach it to work orders, or share it with your maintenance contractor.
Typical maintenance frequency
Suggested intervals for degasser (deaerator) maintenance. Actual frequencies should follow manufacturer guidance and site-specific risk assessments.
Monthly
- •Visual check of operation
- •Verify vent valve is clear
Quarterly
- •Water quality test including dissolved oxygen
- •Check strainer
Annually
- •Full service check
- •Inspect vacuum chamber
- •Review water treatment programme results
Common faults and issues
Issues to be aware of when maintaining degasser (deaerator) equipment.
Safety and compliance notes
Key safety considerations for degasser (deaerator) maintenance. This is general guidance only — always follow OEM instructions, statutory requirements, and your organisation's safe systems of work.
Reference standards and frameworks
- United Kingdom
- HSE ACoP L8 and HSG274 for water hygiene
- North America
- ASHRAE Standard 188 (legionellosis risk management)
Frameworks commonly referenced when planning degasser maintenance programmes. Always confirm the requirements that apply to your site and jurisdiction.
Managing Degasser documentation with PM Assist
PM Assist helps FM and building operations teams search their O&M manuals and building drawings in seconds. Upload your degasser (deaerator) documentation and ask questions like “What are the legionella control requirements?” or “When was the last water quality test?” — and get source-cited answers instantly.
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Related free tools
Related maintenance checklists
Further reading on degasser maintenance
Compliance topics for degasser maintenance
Frequently asked questions
Why is degassing important in a heating system?
How do I know if my degasser is working?
Is a degasser the same as an air separator?
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