HIU Replacement & Upgrade London
HIU replacement swaps a failed or inefficient heat interface unit for a compatible model, re-connects primary and secondary pipework, and commissions the new unit to the network’s design temperatures and flow rates.
Commercial rate: £75+VAT per half hour, minimum 1-hour charge
When to replace rather than repair
Repair is usually the right first step. Replacement makes sense when parts are no longer available, the unit has repeated failures, plate heat exchangers are badly fouled, or the unit cannot hit the low return temperatures the network now needs.
- Obsolete units with no spare parts support
- Repeated failures on the same unit
- Poor return temperatures that hurt network efficiency
- Upgrades during refurbishment or a network improvement programme
HIU replacement cost — what affects it
HIU replacement cost depends on the unit selected, whether the pipework connections match, access within the flat, isolation arrangements in the riser, and whether heat meters need re-fitting or re-registering. We survey first and give a written quote covering the unit, labour and commissioning, so there are no surprises.
Installation and commissioning
Every replacement is finished with commissioning: flushing, filling and venting the secondary circuit, setting the PICV, checking hot water and heating performance, and recording the results for the building file.
Common Questions
How much does an HIU replacement cost?
It depends on the unit, the pipework and the access. We survey first and provide a written quote for the unit, labour and commissioning before any work starts.
Can you fit a different make of HIU?
Often yes, provided it suits the network’s design temperatures, pressures and connections. We check compatibility during the survey.
Will the new unit need commissioning?
Yes. Every new HIU should be commissioned so it delivers hot water and heating properly and returns water to the network at the right temperature.
