- GB version for domestic hot water and direct heating in gas boiler retrofit applications- Dimensioning codes:- 15 – domestic hot water capacity indication (l/min)- St – free of non-ferrous metal brazed stainless steel heat exchanger for domestic hot water preparation- NC – no cold water outlet from heat interface unit- BP – supply lines preheating function- TL – thermostatic temperature limiter for domestic hot water with submersible sensor- DI – primary differential pressure controller at the heat interface unit inlet
