MCR4 19/20 MI dual-function condensing gas boiler 7857047

Future-Ready Boiler – Burns Gas with 20% Hydrogen and Adapts to Fuel Type

This is not an ordinary condensing boiler. It is designed to operate with gas blended with 20% hydrogen – meaning it is ready today, ahead of regulatory changes. The Gas Adaptive system automatically recognizes the gas type (E, Lw, Ls, or propane/butane) and adjusts combustion parameters without manual correction. For Ls gas, an additional conversion kit is required – the only item you need to add yourself.

Modulation from 10% to 100% – Does not operate at full power unless needed

There is no simple "on/off" here – the boiler acts like a meter. The air-gas module enables smooth power adjustment to match current demand. When the house needs little heat, it operates at 10%. When it is cold and the entire system needs heating, it goes up to 100%. This means: lower gas consumption, reduced component stress, and longer service life. Efficiency at full load reaches up to 105.8%, while seasonal heating efficiency stands at 94%. NOx emissions are below 14 mg/kWh – Class 6, the lowest possible.

Stainless Steel Heat Exchanger – 5-year warranty on the whole unit, 8 years on the heat exchanger

The toroidal heat exchanger is neither zinc-coated nor lacquered. It is made of stainless steel – corrosion-resistant, easy to service, and offers better heat conductivity. That is why the manufacturer provides a 5-year warranty on the entire boiler and an additional 3 years (totaling 8 years) specifically on the heat exchanger. There is no "average" cast iron or brass here – only a material that stands the test of time.

Brass Hydraulic Module and Class A Pump

All hydraulic components – pump, heat exchanger, valves – are assembled in a single brass block. This ensures not only corrosion resistance but also greater mechanical durability during servicing. The modulating Class A pump has an EEI below 0.23 – meaning it consumes less energy than most competitors. The central heating safety valve is set at 3 bar; the flow limiter and flow sensor operate without user intervention.

E-Pilot + Smart TC Control – Manage the Boiler from Your Phone

The E-Pilot console features an intuitive interface and weather-based automation – the boiler automatically sets water temperature based on outdoor conditions. Additionally, the Smart TC thermostat can be connected via Wi-Fi. The De Dietrich Smart app (Android/iOS) displays system status, allows temperature adjustments in different zones, enables scheduling, and sends fault notifications. You don't need to be at home to know what's happening.

Compatible with Almost Any Flue Gas System

No need to change the chimney or install a new duct. The boiler works with:

• Ø60/100 mm air/flue gas duct (included in the package),
• B23p or C93 type chimney,
• C53 distributed system,
• C43P collective flue gas system.

Certifications also include C10, C13, C33, and others – making this one of the few boilers with such a wide range of approved solutions.

Compact Size, Lightweight – Hassle-Free Installation

Dimensions: 395 x 700 x 285 mm. Weight: 28.5 kg (approx. 31 kg with water). The expansion vessel (8 liters) is integrated into the support frame – no additional expansion tank installation required. Gas connection and hydraulic ports (3/4" for central heating, 1/2" for domestic hot water) are standard. The Ø60/100 mm air/flue gas connection is pre-installed.

Quiet Operation and Low Losses

Sound power level: 48 dB(A) – comparable to quiet room ambience. Standby losses: only 0.04 kW. Electrical energy consumption: maximum 0.023 kW – equivalent to an LED bulb.