Construction defect · Defects & construction flaws
Heating defects in a new home: 11 essential checks
11 checks to perform when moving in
Heating is the most frequently failing equipment in a new-build. Start-up, hydraulic balancing, airflow, setpoint temperatures, noise, vibration: every point must be checked under warranty. Run a full heat-up cycle (minimum 24h) noting: flow temperature, return, consumption, noise. Demand the commissioning report signed by the heating engineer and verify that each room reaches its setpoint in less than two hours.
Before — compliant
silent HP 38 dB · commissioning OK
Commissioning signed · hydraulic balancing done
⚠ After — defective
noisy HP 52 dB · cold floor
Excessive noise · commissioning missing · to be reported
Reporting procedure in 4 steps
A heating defect must be reported without delay, especially in cold weather. Documentation and chronological evidence are essential.
- 1Measure and documentThermometer in each room, note deviation from setpoint. Sound level meter for noisy HP or boiler. Photo of the boiler, panel, circulator.
- 2Demand the commissioning reportThe commissioning report must be signed by a Cerga-approved installer or equivalent. It proves initial compliance and triggers the warranty.
- 3Formal noticeRegistered letter to the installer AND the main contractor within 90 days. Attach measurements, photos, commissioning report, invoices.
- 4Thermal expert assessmentIf disputed, commission an independent heating engineer. Admissible thermal report · from €380 VAT incl. Cost recoverable if defect confirmed.
Who pays for the repair? Responsibility table
Responsibility depends on the nature of the defect: equipment (two-year) or unfitness for purpose (ten-year).
Defect type
Contractor
Owner
Insurance
Boiler fails to start
✓ two-year warranty
—
—
Underfloor heating unbalanced
✓ two-year warranty
—
—
Heat pump > 50 dB
✓ two-year warranty
—
—
Undersizing (unfit)
✓ ten-year liability
—
ARI
Missed servicing (post-1 year)
—
✓ maintenance
—
Get an inspection
Independent thermal assessment of your heating system
Admissible report · 5-day turnaround · from €380 VAT incl.
FAQ
Common questions about heating
My heat pump is very noisy. Is it a defect?
An air-water heat pump must not exceed 45 dB at 3 metres in night mode under manufacturer standards. Beyond that: installation defect, vibrations, missing anti-vibration mounts. Have it measured with a sound level meter and report.
My underfloor heating has cold zones. What should I do?
This indicates a hydraulic balancing defect in the manifold. The installer must return to balance the loops. Covered by the two-year warranty. Report by registered letter.
How long to reach 20 °C in a new room?
Maximum 2 hours warming up from 15 °C with a correctly sized HP or boiler. Beyond that, the installation is undersized — possible ten-year defect.
The installer requires annual servicing. Is it mandatory?
For gas and oil boilers, yes — annual servicing is mandatory in Wallonia and Brussels. For heat pumps, recommended every two years. Keep invoices: they prove your diligence in a dispute.
How much does an independent thermal assessment cost?
Between €380 and €550 VAT incl. Includes: analysis of installed capacities, balancing check, noise measurements, commissioning report verification. Cost recoverable if defect confirmed.