Buderus GB402-320-5, Installation And Maintenance Instructions For Contractors

Page: 20 / 64

6 Fitting
Logano plus GB402 – 6 720 820 700 (2018/01) 20
▶ At an operating pressure of 3 to 6 bar, seal in female connection [4]
and threaded flange [3] at the distributor connector with a suitable
sealant. Secure safety valve [1] with gasket [2] on the threaded
flange.
▶ Fit the blow-off line to the respective safety valve.
Fig. 16 Safety assembly (3 to 6 bar)
[1] Safety valve
[2] gasket
[3] Threaded flange
[4] Female connection
6.5.3 Connecting the return
▶ Undo the threaded flange from the return.
▶ Fit the threaded flange to the return (on site) (

table 10, page 19).
▶ Insert a gasket between the flange on the boiler and the threaded
flange on the return.
▶ Secure the flange connection with 4 screws, washers and nuts.
Fig. 17 Fitting the return (RK)
Connection the diaphragm expansion vessel (DEV)
To safeguard individual boilers, a DEV can be connected to the ¾ inch
connection on the return, in accordance with EN 12828.
▶ Install the DEV on site to maintain the system pressure in the return,
upstream of the pump.
▶ Observe the accessories installation instructions.
Connecting the drain & fill valve on site
▶ To enable a topping up of the heating water, instruct the user about
the location of the drain & fill valve.
▶ Install a drain & fill valve in the return outside the boiler itself.
▶ Observe the accessories installation instructions.
6.5.4 Installing a DHW cylinder
Make the connection of a DHW cylinder to the flow and return on site.
The MC10 + BC10 control unit can switch the required external cylinder
primary pump (

MC10/BC10 instructions).
We recommend the on-site installation a dirt filter
(accessory) in the return to prevent contamination of the
boiler by the water.