SAV HIU Repair & Service London
SAV is one of the most common HIU brands in London social housing — found throughout Lambeth, Southwark and Tower Hamlets estates. Collide Group carries SAV spare parts on every van, enabling same-day SAV HIU repair for the majority of faults. From diverter valve failure to control board diagnosis, our engineers know SAV systems inside out.
About SAV HIUs
SAV Systems is one of the most prolific HIU manufacturers in the UK social housing sector. SAV Ultraheat, Apollo, HydroHeat and ThermoStar units are installed in thousands of flats across London — particularly on local authority and housing association estates in Lambeth, Southwark and Tower Hamlets. Because of this sheer volume of installed units, SAV faults are among the most common HIU callouts we attend.
SAV units have a predictable set of failure modes. The diverter valve is the most frequent cause of no-hot-water complaints on SAV HIUs. Collide Group carries SAV diverter valves and other common SAV components on every van, meaning the majority of SAV HIU repairs are completed in a single visit — no waiting days for parts to arrive.
- SAV Ultraheat
- SAV Apollo
- SAV HydroHeat
- SAV ThermoStar
Common SAV HIU Faults
SAV HIUs have a characteristic fault profile. Here are the issues our engineers most commonly diagnose and repair:
- Diverter valve failure — the most common SAV fault, causing no hot water or heating
- Plate heat exchanger scaling reducing DHW output and temperature
- Control board faults causing unit lockout or erratic behaviour
- Actuator seal failure leading to valve leaks or stuck positions
- Pressure imbalance causing flow problems across the heating circuit
- Strainer blockage restricting primary flow from the communal system
- Temperature sensor drift causing hot water temperature fluctuation
What We Fix
- SAV diverter valve replacement — same-day with parts on the van
- Plate heat exchanger descale or full swap
- Control board diagnosis, repair and replacement
- Actuator seal and cartridge repair
- Pressure balancing and flow restoration
- Strainer cleaning and blockage removal
- Temperature sensor replacement and calibration
- Emergency callouts — same-day response across London
- Full SAV HIU annual service and compliance check
Other brand HIU specialists: Danfoss HIU Repair · Caleffi HIU Service · Switch2 HIU Repair · All HIU Repair
The Benefits
Same-Day Response
Emergency SAV HIU callouts across Greater London — particularly fast response to Lambeth, Southwark and Tower Hamlets estates.
First-Visit Fix Rate
SAV parts on the van — diverter valves, actuator seals and control components carried for immediate repairs.
Transparent Pricing
Callout from £120 inc VAT — any additional SAV parts or labour quoted before work proceeds.
SAV HIU Repair from £120
Callout fee from £120 inc VAT. SAV spare parts quoted transparently before work begins — and because we carry the most common SAV parts on the van, most repairs are completed first visit.
Book a SAV HIU RepairFrequently Asked Questions
What SAV HIU models do you service?
My SAV HIU has no hot water — what's wrong?
How often should a SAV HIU be serviced?
Do you carry SAV spare parts?
Related HIU Services
SAV HIU Fault? Call Us Now
Same-day SAV HIU repair across London. Parts on the van, transparent pricing, first-visit fix rate.