From April 2018, a new mandatory Boiler Plus scheme applies whenever a new gas boiler is installed in an existing central heating system in England.
Boiler Plus is additional to legislation already published in Part L of the Building Regulations and applies to England only.
The additional policy means:
all gas boilers replaced in existing buildings must be at least 92% efficient under the ErP European rating system
a boiler interlock, time control, and temperature control must either be already present or be installed and in working order
gas combi boiler replacement will require (at least) one additional measure out of the following 4 options
(1) flue gas heat recovery system (FGHR)
(2) weather compensation
(3) load compensation
(4) smart thermostat with automation and optimisation