HIU installations and boosted cold water systems for apartment blocks
PipeSaxis Mechanical delivers HIU installation and boosted cold water systems for multi-storey residential buildings across England. We work as a mechanical subcontractor to developers and main contractors, installing heat interface units at apartment level alongside booster pump sets, break tanks and the distribution pipework that connects plant room to dwelling. Every package is supervisor-led, QA-controlled and supported by the documentation your project team needs at handover.
Apartment-level systems only perform when the interface between landlord plant and individual dwellings is engineered properly. Our teams coordinate with heat network designers, pump set suppliers and fit-out trades to keep risers, laterals and HIU positions aligned with the programme. Works are sequenced floor by floor, pressure tested in stages and recorded with photo evidence, so commissioning and snagging run from a verified baseline rather than assumptions.
SVC-05 / Scope
What this package covers
01
HIU installation
Supply-and-fit or fit-only installation of heat interface units at apartment level, including isolation valves, filtration, flushing bypasses and connections to heat network laterals.
02
Boosted cold water
Booster pump sets, break tanks and pressurised distribution designed to maintain stable flow and pressure to every floor of a multi-storey block.
03
Risers and laterals
Installation of heating and cold water risers with floor-by-floor laterals, sleeved penetrations, anchors and guides, coordinated against builders' work and service zones.
04
Plant room interface
Connections between landlord plant rooms and apartment systems, including manifolds, zone valves, metering positions and clear demarcation of landlord and dwelling assets.
05
Flushing and testing
Staged pressure testing, flushing and water treatment of risers, laterals and apartment circuits, with test records issued as each section is signed off.
06
Commissioning support
Attendance for HIU commissioning, pump set setup and balancing alongside specialist commissioning engineers, plus witnessing support for client and consultant inspections.
07
HIU replacement programmes
Phased replacement of ageing heat interface units in occupied blocks, with resident liaison handled through your property manager and minimal interruption per dwelling.
08
Coordination and QA
Supervisor-led delivery with marked-up drawings, photo evidence and inspection records, keeping mechanical works aligned with other trades and the construction programme.
Built for
- Main contractors delivering multi-storey residential schemes
- Developers procuring development plumbing packages for apartment blocks
- M&E contractors needing a technical pipework delivery partner
- Property managers planning HIU replacement in occupied buildings
- Housing providers and build-to-rent operators upgrading boosted cold water plant
QA & Documentation
- Task-specific RAMS and COSHH assessments issued and approved before works start on site
- Pressure test records for every riser, lateral and apartment circuit, witnessed where the specification requires
- Photo evidence of concealed pipework, sleeving and connections captured before ceilings and risers are closed
- HIU commissioning sheets and pump set setup records compiled per dwelling and per plant area
- Structured snagging process with tracked close-out and re-inspection before practical completion
- Handover packs including test certificates, flushing records, O&M information and as-installed mark-ups
SVC-05 / Delivery
How the package is delivered
Stage 01
Scope and review
Send drawings, schematics and the HIU or pump set specification. We review the design, flag interface risks early and return a priced scope with clear programme assumptions.
Stage 02
RAMS and mobilisation
Task-specific RAMS, COSHH assessments and lifting plans are issued for approval before mobilisation, with supervisors inducted and toolbox talks recorded on site.
Stage 03
Sequenced installation
Risers, laterals, HIUs and booster plant are installed floor by floor to the agreed sequence, with progress photographed and marked up against drawings.
Stage 04
Testing and flushing
Each section is pressure tested and flushed in stages, with witnessed tests where the specification requires and records issued as sections complete.
Stage 05
Commissioning and handover
We attend commissioning, close out snagging and issue a document-supported handover pack covering test certificates, photo evidence and as-installed information.
SVC-05 / FAQ
Direct answers for commercial buyers
Yes. We deliver HIU installation as a subcontract package for main contractors and developers, fit-only or supply-and-fit. Works are supervisor-led and sequenced to your programme, with RAMS submitted for approval, progress reporting through your site management and test documentation issued floor by floor. Nationwide subcontracting for planned commercial and development works is available across England.
Most buildings above four to five storeys cannot rely on mains pressure alone to serve upper floors reliably. A boosted system uses a break tank and booster pump set to deliver consistent pressure and flow to every level. The right configuration depends on storey height, dwelling count, simultaneous demand and the incoming main, which is why we review hydraulic calculations and the pump set specification before pricing.
Yes. Replacement programmes are planned dwelling by dwelling, with isolation, drain-down and changeover sequenced to keep interruption to each apartment short and predictable. We coordinate access through your property manager or managing agent, protect finished areas, and record each completed unit with photos and commissioning sheets. Like-for-like swaps and upgrades to different HIU models are both supported.
Each package closes with a document-supported handover pack: pressure test certificates, flushing and water treatment records, HIU commissioning sheets per dwelling, pump set setup data, photo evidence of concealed works and as-installed mark-ups. Snagging is tracked to close-out before practical completion. Certification and insurance details available on request.
Most HIUs are indirect units fed from a communal heat network, so no gas work takes place within the apartment and Gas Safe registration is not required for the installation itself. Where a scheme involves gas-fired plant or gas connections, we are Gas Safe registered where gas works are undertaken. We confirm the demarcation between heat network, gas and water scopes at enquiry stage.
Send us your HIU package scope
Share drawings, schematics and dwelling counts, and we will return a priced scope with programme assumptions for your apartment scheme.