Heating systems with domestic hot water heated by an indirect cylinder
Heating system diagram: unmixed heating circuit without a low loss header
The heating system consists of:
- a wall-hung gas condensing boiler with an integrated three-way valve
- one unmixed heating circuit
- a hot water cylinder
- a weather-compensated controller or room controller
Features:
- domestic hot water heated by an indirect cylinder
- install the safety group in accordance with DIN 1988
- check the water content of the system to see whether an additional expansion vessel is required
- no thermostatic radiator valve may be fitted in the reference room of the FR 110 room controller
- in heating systems with a flow rate of up to 1000l/h the low loss header can be omitted
- the DHW circulation pump can be wired directly to the boiler electronics. In that case the circulation pump programme is controlled by the FW 100 or the FR 110
Heating system diagram: unmixed heating circuit with a low loss header
The heating system consists of:
- a wall-hung gas condensing boiler with an integrated three-way valve
- one unmixed heating circuit
- a hot water cylinder
- a weather-compensated controller
Features:
- domestic hot water heated by an indirect cylinder
- install the safety group in accordance with DIN 1988
- check the water content of the system to see whether an additional expansion vessel is required
- in heating systems with a flow rate of up to 1000l/h the low loss header can be omitted
- the DHW circulation pump can be wired directly to the boiler electronics. In that case the circulation pump programme is controlled by the FW 100
- allow for a mechanical safety limiter as specified by the underfloor heating manufacturer
How it works:
Heating systems with conventional hot water heating and a low loss header are built with the usual hot water priority for the cylinder. The unmixed heating circuit with a low loss header is preferably controlled by the FW 100 weather-compensated controller. The heating pump for the heating circuit (secondary circuit) is activated by the boiler. Temperature is controlled using the VF sensor in the low loss header, again via the condensing boiler. The TB temperature sensor in the underfloor heating circuit is also connected to the boiler. The FW 100 controller can be mounted in a room or built into the boiler. If it is built into the boiler, the heating system can be controlled from the room using the FB 10 or FB 100 remote control. The boiler and the controller communicate over a two-wire bus system. Alternatively, the FR 110 room controller can be used.
Heating system diagram: mixed heating circuit with a low loss header
The heating system consists of:
- a wall-hung gas condensing boiler with an integrated three-way valve
- one underfloor heating circuit
- a hot water cylinder
- a weather-compensated controller
Features:
- domestic hot water heated by an indirect cylinder
- install the safety group in accordance with DIN 1988
- check the water content of the system to see whether an additional expansion vessel is required
- in heating systems with a flow rate of up to 10001/h the low loss header can be omitted
- the DHW circulation pump can be wired directly to the boiler electronics. In that case the circulation pump programme is controlled by the FW 100
- allow for a mechanical safety limiter as specified by the underfloor heating manufacturer
How it works:
In heating systems with large cylinders, or where uninterrupted heating must be ensured, the cylinder is always connected on the secondary side of the low loss header.
To run one mixed circuit and hot water heating in parallel, an FW 100 weather-compensated controller is needed together with the IPM 2 switching module. The IPM 2 module controls and monitors the mixed heating circuit with its heating pump, the three-way valve, the temperature limiter and the sensor. The cylinder with its charging pump is also controlled via the IPM 2, as is temperature control using the VF sensor in the low loss header.
Heating system diagram: one mixed and one unmixed heating circuit
The heating system consists of:
- a wall-hung gas condensing boiler with an integrated three-way valve, or a combi boiler
- one unmixed heating circuit
- one mixed heating circuit
- a hot water cylinder
- a weather-compensated controller and a quick-fit kit (can be replaced by individual components)
Features:
- domestic hot water heated by an indirect cylinder, or without a cylinder in the case of a combi boiler
- install the safety group in accordance with DIN 1988
- check the water content of the system to see whether an additional expansion vessel is required
- the DHW circulation pump can be wired directly to the boiler electronics. In that case the circulation pump programme is controlled by the FW 200.
How it works:
For heating systems with two heating circuits it is advisable to use the HW 2 U/G-3 quick-fit kit, which contains all the hydraulic and control components required, including the low loss header and the IPM 2 module. The quick-fit kit is connected electrically by means of a mains plug (the kit can be replaced by standard Junkers components and other parts available on our market). Communication with the FW 200 controller is over a two-wire bus system.
