Check And Correct The Operating Pressure; When Should You Check The Operating Pressure In The Heating System; Sealed Unvented Systems - Bosch Uni Condens 8000 F Installation And Maintenance Instructions Manual

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Fig. 41 Opening/closing the cleaning drain
[1] Cap of cleaning drain
[2] Cleaning drain
After cleaning:
▶ Mount siphon on condensate pipe.
▶ Connect the drain hose to the condensate drain.
▶ Check gasket on burner door and replace if required
( chapter 10.3.4, page 36).
If you open the cleaning cover of the flue gas collector, the gasket on the
cleaning cover must be replaced ( chapter 10.3.4, page 36)
▶ Close and secure the burner door ( chapter 6.9.1, page 20).
▶ Close and tightly seal the cleaning cover on the flue gas collector
( chapter 10.3.5, page 36).
▶ Continue to ensure adequate ventilation of the installation location.
▶ Remove the foil from the control unit.
▶ Start up the heating system ( chapter 8, page 33).
10.4

Check and correct the operating pressure

Operation without a sufficient volume of water is not permitted.
▶ Only operate the system when it contains a sufficient volume of water
(operating pressure).
If the operating pressure in the heating system is too low.
▶ Fill the heating system with top-up water.
For the water quality:
▶ Note the information specified in the operator's log.
▶ Check the operating pressure once a month.
10.4.1 When should you check the operating pressure in the
heating system?
The fill and top-up water quality must comply with the specifications in
the operator's log supplied.
Air pockets may form in the heating system through the fill or top-up
water releasing gases.
▶ Vent the heating system (e.g. at the radiators).
▶ If required, top up with water.
Recently added fill or top-up water loses much of its volume in the first
few days because it releases gases.
Uni Condens 8000 F – 6720867056 (2016/10)
With newly filled systems:
▶ Initially check the operating pressure of the heating water daily and
then in ever increasing intervals.
Once the heating system is hardly losing any volume:
▶ Check the operating pressure of the heating water once a month
A distinction is made between open and closed systems. In practice,
open vented systems are rarely installed nowadays. We will therefore be
using a closed heating system to demonstrate how you can check the
operating pressure. All settings will have already been made by the
contractor when the system was first commissioned.

10.4.2 Sealed unvented systems

NOTICE:
System damage due to frequent topping up!
Subject to the water quality, your heating system can be damaged
through corrosion or scaling.
0010014753-001
▶ Ensure that the heating system is vented correctly.
▶ Check the heating system for leaks and the expansion vessel for
functionality.
▶ Observe the requirements regarding water quality
( operator's log).
▶ If water loss occurs frequently, locate the cause and rectify the
problem without delay.
NOTICE:
System damage due to temperature stresses!
▶ Only fill the heating system when cold
(the flow temperature must not exceed 40 °C).
▶ During operation, only fill the heating system via the filling facility in
the heating system pipework (return).
In closed systems, the pressure gauge needle ( fig. 42, [3], page 37)
must be within the green marking [2]. The red needle [1] of the pressure
gauge must be set to the minimum pressure required for the heating
system.
▶ Check the operating pressure of the heating system.
If the pressure gauge needle [3] drops below the green marking [2]:
▶ Top up with water.
▶ Top up with water via a filling facility in the heating system pipework.
▶ Remove air at the heating system.
▶ Check the operating pressure again.
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Fig. 42 Pressure gauge for sealed unvented heating systems
[1] Red needle
[2] Green marking
[3] Pressure gauge needle
Inspection and maintenance
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