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If you operate or maintain a combined heat and power plant (CHP), the Combined Heat and Power Quality Assurance Programme (CHPQA) matters because it is the UK government’s route for assessing whether a scheme qualifies as ‘Good Quality CHP’. The programme has been part of the UK CHP plant parts landscape since the original CHPQA Standard was first published in 2000, the purpose being to assess the quality of a CHP scheme using defined evidence related to fuel input, useful heat output, power output, scheme boundaries, metering and annual operating performance.
In March 2026, the Standard and guidance notes were updated to align with the CHPQA Portal now hosted on GOV.UK. Operators now have to register schemes and submit self-assessments through that portal. The practical consequence is simple: your operating record needs to describe the plant as it actually runs, not as it appeared in an old purchasing file, commissioning document or stores list. What does this mean for correct part specification, and how does it impact your operational risk? Read on to find out.
What Does CHPQA Have To Do With Replacement Parts?
CHPQA does not tell an operator which CHP plant parts, spark plugs, ignition leads, fuel filters, oil level controllers or sensors to buy. However, CHPQA compliance does depend on the engine producing reliable and explainable performance over the assessment period.
That is why specification control is becoming increasingly operationally important following the update. A wrong or poorly evidenced component can contribute to missed starts, derating, unstable combustion, repeat trips, poor recovery after maintenance, or unnecessary downtime. Those events affect the operating history behind the scheme’s annual performance data. For a CHP site, a spare part is therefore not just a stock item to be treated like a spare keyboard or paperclip, but part of the technical chain that supports availability, output and evidence.
Why Are Old Spares Records A Risk?
Depending solely on old spares records for your specifications is an operational risk because a previous order may show what was bought, but it doesn’t prove that the same part is still correct for the engine now installed.
Industrial gas engines change over time as components are and emergency repairs introduce equivalents that may never be added properly to the technical record. The risk is not that engineers specify parts casually. On well-run CHP sites, replacement components are normally selected from drawings, OEM documentation, service records, fitted component references, supplier data and engineering judgement.
The problem appears when those references stop agreeing with one another. The part fitted to the engine may be correct, but the purchasing record, stores description, supplier reference and original equipment schedule may not all describe the same configuration.
For CHPQA-relevant plant, that is the operational risk. If availability, output stability or maintenance history later needs to be reviewed, the site must be able to show which specification was current at the time, why the replacement matched the installed system, and whether any alternative had been accepted for repeat use.
Correct specification is therefore not only about selecting the right part on the day, but about preserving enough technical context for the next engineer, buyer or maintenance planner to make the same decision without reconstructing it from incomplete records.
What Should Be Recorded Before A Replacement Is Approved?
The approval record should be specific enough to prevent the same decision being remade from scratch during the next fault, shutdown or CHPQA review. It should identify the engine, the installed system, the component selected and the evidence used to accept it. Where an alternative is used, the record should state whether it is a manufacturer supersession, an approved equivalent or a temporary substitution. It should also capture who accepted it, the basis for acceptance, and any restriction on repeat use.
How A Specialist Supplier Helps Preserve Specification Control
The answer is to make your supplier part of the specification control process, not just the fulfilment route. A good industrial gas engine parts supplier should be able to help confirm any supersessions, check equivalents against the installed engine, identify configuration-sensitive details, and keep a clear trail between the fitted component, the ordered replacement and any approved alternative. This gives your engineers a cleaner record to work from when the same decision comes back during the next CHPQA reporting period.
Find Out More
To find out more about CHP plant parts and how to specify the right components for your application, please contact the specialists at R&M Walsh today by clicking here, or call us directly on 01782 983592.
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