Drazice TO 10 IN/UP, Operating And Installation Manual

Page: 28 / 54

- 28 -
E
N
7. PLUMBING FIXTURE
Water inflow and outflow is indicated with different colour terminals on the heater tubes. Cold water
supply is indicated with blue and hot water outflow is indicated with red. There are two ways of connecting
the water heater to water network. Closed, pressure connection system allows water withdrawal at
multiple supply (withdrawal) points whilst open flow system allows one supply (withdrawal) point only.
With regard to the selected way of connection, you need to purchase suitable combination faucets. For the
open flow system you need to mount a return valve in front of the heating element in order to avoid water
outflow from the boiler if water supply gets discontinued. For this type of connection, you have to use the
flow combination faucet. Due to heating, the volume of water increases, which causes water dripping from
the combination faucet pipe. You will not prevent water from dripping by strong tightening of the
combination faucet valve but you may damage the combination faucet.
For the closed pressure connection system you need to use pressurised combination faucets at the
withdrawal points. You have to attach a safety valve to the filling pipe to avoid increase of pressure in the
tank above the rated pressure. During water heating in the heater, the water pressure in the tank increases
until it reaches the limit set on the safety valve.
Open (flow) system Closed (pressure) system
The “above-supply-point” version The “above-supply-point” version
The “below-supply-point” version The “below-supply-point” version
Explanation:
1 – Safety valve
6 – Test adaptor
2 – Back pressure valve 7.7a – Flow combination faucet
3 – Test valve 8 – Funnel with connector to drain from the safety valve
4 – Reduction valve H – Cold water
5 – Shut-off valve T - Hot water
Safety valve is mounted on the cold water inlet identified with a blue ring. Each hot service water
pressure heater must have a safety valve with a membrane spring. Nominal clearance of safety
valves is defined in the ČSN 0 60830 standard. The safety valve must be well accessible, as near to
the heater as possible. The input pipes must have at least the same clearance as the safety valve.
The safety valve is placed high enough to secure dripping water drain by gravity. We recommend