Taconova’s TacoTherm Dual Zepto 10/26 heat interface unit (HIU) has passed all four modules of the BESA UK HIU Test Regime V3-Rev002 (March 2026) and is now listed on the BESA HIU Test Register.
UKAS-accredited laboratory, Enertek International, carried out testing on a production sample. On a 70°C network, the unit recorded a domestic hot water Volume Weighted Average Return Temperature (VWART) of 17°C, against a BESA pass threshold of 20°C. Maximum hot water output was 42.0kW.
The unit also passed on a 55°C primary network at 36.1 kW, the heat pump readiness point.
The unit delivered hot water in 10 seconds on a 70°C network and passed every safety criterion on scalding and scaling exceedances.
Behfar Abedinia, General Manager of Taconova UK, commented: “Ofgem took on regulation of heat networks in January 2026, and technical standards follow in 2027. Specifiers are being asked to evidence performance, not assert it. Independent testing to the 2026 BESA regime gives them return temperature data they can put straight into a design case.”
The TacoTherm Dual Zepto is an indirect, dual-service HIU providing instantaneous domestic hot water and indirect space heating. The unit is WRAS approved and comes prepared for heat meter installation.
The full test results can be found on the BESA HIU Test Register.
Image: Closed view of the TacoTherm Dual Zepto 10/26 Heat Interface Unit installation at the Ironworks development. (Image: Taconova)