Special systems
Heating system diagram: Heating system with a solid fuel boiler, solar water heating and two mixed circuits
The heating system consists of:
- a wall-hung gas condensing boiler
- one mixed radiator heating circuit
- one mixed underfloor heating circuit
- a solar cylinder
- a solid fuel boiler
Features:
- check the volume of water in the system to see whether an additional expansion vessel is needed
- install the safety group in accordance with DIN 1988
- the circulation pump can be connected electrically directly to the boiler electronics. In this case the circulation pump programme is controlled via the FW 200
- for more detailed information on solar systems, see the "solar systems" section
- the heating pump supplies the heating network as far as the low-loss header
Description of operation:
The system is controlled by the FW 200 controller. The two mixed circuits on the secondary side of the low-loss header are activated via the IPM 2 module. The independently operated solid fuel boiler with a buffer tank transfers heat to the secondary circuit of the heating network when the buffer tank temperature is high enough.
In addition to solar water heating, the ISM 2 solar module also controls the transfer of heat from the buffer tank by comparing the buffer tank temperature T3 with the return temperature of the heating circuits T4. When the set temperature difference is reached, the ISM 2 switches the three-way diverter valve, which allows heat to be transferred to the secondary heating circuit.
The heating pumps on the secondary side then deliver the heated heating water from the buffer tank to the heating circuits as required.
The solar system is activated by the ISM 2 module, which switches on the solar pump according to the current temperatures at the sensors. The IPM 2 module controls the cylinder charging pump depending on the cylinder temperature sensor. In the diagram the ISM 2 module is built into the solar pump station, but for our market it is supplied separately. The ISM 2 and IPM 1 modules communicate with the FW 200 controller via a two-wire bus system.
Heating system with a solid fuel boiler, solar water heating and two mixed circuits
Heating system diagram: Heating system with a solid fuel boiler, a gas condensing boiler for top-up heating and solar support for heating and hot water
The heating system consists of:
- a wall-hung gas condensing boiler with an integrated three-way valve
- one mixed heating circuit
- a solar combination cylinder for heating support
- a solid fuel boiler
Features:
- check the volume of water in the system to see whether an additional expansion vessel is needed - install the safety group in accordance with DIN 1988
- check whether an additional safety valve SV is needed on the solar cylinder
- the circulation pump can be connected electrically directly to the boiler electronics. In this case the circulation pump programme is controlled via the FW 200
- for more detailed information on solar systems, see the "solar systems" section
Heating system diagram: Solar water heating with a central buffer tank, a hot water cylinder and two collector arrays facing in different directions
Description of operation:
Heating systems with a solar installation and a high hot water demand are built with the cylinders connected in series. The water in the preheat cylinder (buffer tank) is heated by the solar system and fed from there into the standby cylinder. With high solar gains, the preheat cylinder may even reach a higher temperature than the standby cylinder. The controller then activates the transfer pump UL so that warmer water flows into the standby cylinder. Operating the whole system requires the FW 500 weather-compensated controller in conjunction with the IPM 1 switching module. The IPM controls and monitors the heating pump, the three-way mixing valve, the temperature limiter, the temperature sensor of the mixed heating circuit and the flow temperature sensor in the low-loss header.
The switching functions of the solar system are carried out by the ISM 2 solar module. An additional ISM 1 solar module is required to activate the solar pump PA of the second collector array and the secondary circuit pump PD of the external heat exchanger WT.
