Bosch EZH 42 External Commercial Electric Boiler 42 kW

Optimize energy deployment and secure absolute operational reliability in large-scale properties with the Bosch EZH 42 external commercial electric boiler unit. 

This high-capacity, heavy-duty electric boiler is engineered specifically to serve as an intelligent booster, auxiliary supplement, and standby backup heat source in multi-family housing, commercial buildings, and industrial complexes. By pairing this unit with Bosch Compress commercial ground source heat pumps (such as the Compress 7000 LW 38–80 kW series), you establish a complete, highly versatile system architecture capable of managing seasonal peak heating loads during the coldest winter periods.

Flexible and Modulating 3-Stage Power Regulation

The Bosch EZH 42 features an advanced, multi-stage electric control layout that operates across three fixed steps. The maximum output thresholds can be easily adjusted and restricted during the structural installation phase to match the property's pre-existing electrical infrastructure and precise thermal demands. The control matrix can be assigned to multiple restricted output baselines including 15 kW, 18 kW, 21 kW, 24 kW, 30 kW, 36 kW, or unlocked to utilize the full 42 kW capacity. This modulating feature effectively prevents electrical grid overloading spikes.

Rigid Wall-Mounted Chassis with Consolidated Protection

This industrial-grade electric boiler is configured as a compact, wall-mounted enclosure module, preserving valuable floor space inside tight utility extensions or centralized mechanical plant rooms. Within the reinforced sheet metal housing, all primary technical safety controls come pre-assembled and factory-tested. The unit is equipped with a integrated high-limit safety cut-out toggle and embedded temperature sensors that continuously loop system data back to the primary heat pump manager for a fully automated operational sequence.

Complete Integration with Large-Scale Hydronic Loops

Boasting a structural width of 1050 mm and a depth profile of 730 mm, the Bosch EZH 42 contains heavy-gauge heating elements engineered for demanding, continuous operation over extended lifecycles. The generous structural connection interfaces accommodate high volumetric flow rates, restricting localized pressure drops and ensuring rapid thermal delivery to building distribution circuits or external buffer storage tanks. Please note that the electrical line connection requires 400V 3N~ and must be fused at 3x63 Amps when utilizing the unrestricted 42 kW output tier.

Product Advantages:

• High Commercial Output: Delivers high auxiliary heating power with an adjustable peak capacity of up to 42 kW.
• 3-Stage Power Modulation: Multi-step booster configurations that can be locked down from 15 kW up to peak values.
• Space-Saving Footprint: Wall-mounted layout preserves valuable floor area inside mechanical rooms.
• Consolidated Safety Controls: Ships pre-packed with internal temperature sensors and a thermal cut-out switch.
• Automated System Bridging: Engineered to interact natively with primary Bosch commercial heat pump controllers.

Technical Specifications:

• Model: Bosch EZH 42
• Article Number (SE RSK): 6223509
• EAN Number: 4057749087478
• Supplier Part Number: 8733705536
• Maximum Heating Capacity: 42 kW (Modulating/adjustable 15–42 kW)
• Selectable Power Restrictions: 15, 18, 21, 24, 30, 36, 42 kW
• Required Fuse Rating (Max Output): 3x63 A (Fusing can be restricted to 3x25 A when locked at 15 kW)
• Dimensions Including Connections (WxDxH): 1050 x 730 x 280 mm
• Supply Voltage: 400V, 3N~ 50Hz
• Net Weight: 35.0 kg
• Energy Efficiency Class: A+++ (Applies as system accessory to heat pumps rated A+++)

Please note that the manufacturer’s full warranty is not applicable for units bought in Sweden and installed outside Sweden.