11.13 Installing The Gas-Air Mixture Unit; 11.14 Draining The Product; Checking The Admission Pressure Of The Expansion Vessel; Completing Inspection And Maintenance Work - Vaillant ecoFIT pure 825 Installation And Maintenance Instructions Manual

12 Decommissioning the product

11.13 Installing the gas-air mixture unit

1. Install the burner.
2. Install two new burner seals in the burner cover.
3. Install the gas-air mixture unit.
4. Tighten the screws on the gas-air mixture unit to 7 Nm.
5. Install the flue gas pipe.
6. Install the air intake pipe.

11.14 Draining the product

1. Close the service valves of the product.
2. Start check programme P.05.
Overview of the check programmes (→ Page 15)
3. Open the drain valves.
11.15 Checking the admission pressure of the
expansion vessel
1. Drain the product. (→ Page 28)
2. Measure the pre-charge pressure of the expansion ves-
sel at the vessel valve.
Conditions: Pre-charge pressure < 0.075 MPa (0.75 bar)
▶
Top up the expansion vessel in accordance with the
static height of the heating installation, ideally with ni-
trogen, otherwise with air. Ensure that the drain valve is
open when topping up.
3. If water escapes from the valve of the expansion
vessel, you must replace the expansion vessel
(→ Page 23).
4. Fill and purge the heating installation. (→ Page 17)
11.16 Completing inspection and maintenance
work
1. Check the gas connection pressure (gas flow pressure).
(→ Page 18)
2. Check the CO₂ content. (→ Page 19)

11.17 Checking the product for leak-tightness

▶
Check that the product is leak-tight. (→ Page 19)
12 Decommissioning the product
▶
Switch off the product.
▶
Disconnect the product from the power mains.
▶
Close the gas isolator cock.
▶
Close the cold water stop valve.
▶
Drain the product. (→ Page 28)

13 Customer service

To ensure regular servicing, it is strongly recommended
that arrangements are made for a Maintenance Agreement.
Please contact Vaillant Service Solutions for further details:
Telephone: 0330 100 3461
28
Installation and maintenance instructions ecoFIT pure 0020230531_01