The performance gapis a commissioning story.
Median field SPF of 2.80. Monitored installs above 4.40. SPF is seasonal efficiency measured in real homes, the field cousin of the certificate's SCOP. Most of the distance between those numbers is commissioning, the set-up and tuning done when a system first goes live, and it is checkable in the first 48 hours.
2.80
Median SPF in the BEIS Electrification of Heat Demonstration Project
A strong signal that field performance is far below what well-installed systems can achieve.
4.40+
Publicly monitored high-performing installations
The technology performs materially better when the installation and setup are right.
48 hours
The first useful verification window
Enough time to spot whether the installed system is behaving like the design intent or still sitting on poor defaults.
£200–£400
Typical warranty callout cost
The cost of finding quality issues late instead of proving them quickly with evidence.
Most of the gap is made at commissioning.
The difference between median field performance and strong monitored performance is mostly what happens at commissioning. Three failure patterns account for most of it.
Factory defaults left in place
Flow temperatures, weather compensation and commissioning settings are often left closer to factory assumptions than the home they were installed into.
Design intent is lost at handover
What was assumed in design rarely survives intact into installation and aftercare, so teams are forced to reconstruct the context later.
Paper checks do not verify real behaviour
Self-reported checklists record that a step happened. They do not prove the system actually behaved as expected once live.
What governed commissioning verification looks like.
Not remote monitoring, not a checklist. An evidence-backed decision on whether the installed system behaved as designed.
Expected performance baseline
Start from the design assumptions, system settings and operating envelope that describe a correct installation.
Observed behaviour in the first hours
Early telemetry and live performance signals show how the installed system is actually behaving.
Evidence-backed quality decision
Predicted and observed behaviour compared, exceptions surfaced, and a record kept of what was found and what happens next.
What a first deployment proves.
A first deployment does not have to prove the whole company. It proves the OEM sees quality issues sooner, decides with evidence, and knows where the record should extend next.
- Which installations look correct and which need review first
- Whether certain installer cohorts, regions or system types drift more than others
- Which issues are commissioning and configuration problems rather than product defects
- What evidence is missing from the quality process today
- Where the record should extend next across the base you answer for
- OEM assessment and quoting run on HeatAssure in production today.
How the numbers are validated is on Technology.
Where these numbers come from.
This page summarises the argument in The Commissioning Quality Gap. The key public references behind it:
Field performance and commissioning
BEIS Electrification of Heat Demonstration Project, Energy Saving Trust field trials, and public monitoring data such as HeatPumpMonitor.org.
Market and quality pressure
Heat Pump Association market reporting, the MCS quality framework, and the commercial pressure to scale without letting installation quality drift.
Asked when this proof is read.
Use the proof on your own installs.
If commissioning quality is already visible as a service, warranty or installer problem, the next step is a scoped Commissioning Verification deployment.