Caleffi HIU Repair & Service London
Caleffi HIUs are Italian-engineered precision units found in newer residential developments across Wandsworth, Westminster and private schemes throughout London. Their hydraulic sophistication means they need engineers who genuinely understand Caleffi systems — not just a general plumber. Collide Group engineers specialise in Caleffi HIU repair and service, bringing expert knowledge of Caleffi hydraulics to every callout.
About Caleffi HIUs
Caleffi is an Italian hydronic engineering company with a global reputation for precision-engineered heating components. Their HIU range — including the CaleffiStation and district heating units — is specified in private and mixed-use residential developments where build quality and hydraulic performance are priorities. Caleffi units typically feature high-quality thermostatic cartridges, zone valves and pressure regulation components that require specialist knowledge to service correctly.
Because Caleffi is less common than SAV or Danfoss in volume social housing, fewer engineers carry the right knowledge and parts. Collide Group engineers understand Caleffi hydraulics, carry Caleffi-compatible components and can correctly diagnose the thermostatic cartridge and zone valve faults that most commonly affect Caleffi HIUs in London developments.
- Caleffi CaleffiStation
- Caleffi HIU
- Caleffi district heating units
- All Caleffi residential variants
Common Caleffi HIU Faults
Caleffi HIUs have a specific fault profile driven by their hydraulic architecture:
- Thermostatic cartridge failure causing loss of hot water temperature control
- Pressure relief valve issues leading to pressure loss or dripping
- Heat exchanger fouling reducing hot water output and efficiency
- Zone valve faults preventing heating or DHW from switching correctly
- Flow balancing issues causing uneven heat distribution across circuits
- Actuator wear resulting in valve position errors
- Strainer blockage on primary circuit connection
What We Fix
- Thermostatic cartridge replacement — all Caleffi models
- Pressure relief valve inspection, service and replacement
- Heat exchanger descale or full swap
- Zone valve diagnosis and replacement
- Flow balancing and hydraulic commissioning
- Actuator replacement and valve position correction
- Strainer cleaning and primary circuit blockage removal
- Full Caleffi HIU annual service and compliance report
- Emergency callouts — same-day response across London
Other brand HIU specialists: Danfoss HIU Repair · SAV HIU Repair · Switch2 HIU Repair · All HIU Repair
The Benefits
Same-Day Response
Emergency Caleffi HIU callouts across Greater London — same-day response to Wandsworth, Westminster and all London boroughs.
First-Visit Fix Rate
Caleffi-compatible components on the van — thermostatic cartridges, zone valves and pressure components for immediate repairs.
Transparent Pricing
Callout from £120 inc VAT — any additional Caleffi parts or labour quoted clearly before work proceeds.
Caleffi HIU Service from £120
Annual Caleffi HIU service or repair callout from £120 inc VAT. All parts and additional labour quoted transparently before work begins.
Book a Caleffi HIU ServiceFrequently Asked Questions
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Caleffi HIU Fault? Call Us Now
Same-day Caleffi HIU repair and service across London. Specialist hydraulic knowledge, transparent pricing.