12.10 Installing The Compact Thermal Module; 12.11 Draining The Product; Checking The Pre-Charge Pressure For The Internal Expansion Vessel; Checking The Filling Pressure Of The Heating Installation - Vaillant ecoTEC pro Installation And Maintenance Instructions Manual

4. Tilt the electronics box forward.
5. Remove the clamp (2).
6. Remove the pipe (1) from the product.
7. Rinse the filter under a jet of water, holding it against
the direction of flow.
8. If the filter is damaged or it can no longer be cleaned
sufficiently, you must replace the filter.
9. Refit the pipe.
10. Reinsert the clamp.
11. Always use new seals and retighten the cap nuts and
the lock nut.
12. Open the cold water stop valve.

12.10 Installing the compact thermal module

7
6
5
4
1. Connect the compact thermal module (2) to the heat
exchanger (1).
2. Tighten the four nuts (7) in a cross-wise pattern until the
burner flange fits closely and uniformly onto the mating
surfaces.
–
Tightening torque: 6 Nm, if a torque spanner is
available
3. Connect the plugs (3) to (6) again.
4. Connect the gas pipe using a new seal. In the process,
secure the gas pipe against twisting.
5. Open the gas stopcock.
6. Make sure that there are no leaks.
7. Check that the sealing ring in the air intake pipe is posi-
tioned correctly in the seal seat.
8. Reconnect the air intake pipe to the intake stub.
9. Secure the air intake pipe with the retaining screw.
10. Check the gas flow pressure.
34
2
1
1
2
3

12.11 Draining the product

1. Close the service valves of the product.
2. Start the check programme P.06 (diverter valve mid-
position).
3. Open the drain valves.
4. Make sure that the cap of the automatic air vent on
the internal pump is open so that the product can be
drained fully.
12.12 Checking the pre-charge pressure for the
internal expansion vessel
1. Close the service valves and drain the product.
2. Measure the pre-charge pressure of the expansion ves-
sel at the vessel valve.
Condition: Pre-charge pressure < 0.075 MPa (0.75 bar)
▶
Ideally, you should top up the expansion vessel with
nitrogen. Otherwise, top it up 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 37)
4. Fill the heating installation. (→ Page 26)
5. Purge the heating installation. (→ Page 27)
12.13 Checking the filling pressure of the heating
installation
1. Check the filling pressure of the heating installation, top
it up with heating water, if necessary, and purge it.
2. Fill the heating installation. (→ Page 26)
3. Purge the heating installation. (→ Page 27)

12.14 Checking the quality of the heating water

▶
Check the quality of the heating water: Clarity (clouding),
correct inhibitor and pH value. (→ Page 25)
12.15 Completing inspection and maintenance
work
▶
Start a test operation after the maintenance.
▶
Check the heating mode and, if required, the domestic
hot water generation (if available).
▶
Check the gas flow pressure. (→ Page 28)
▶
Check the CO₂ content and, if necessary, adjust it (air
index setting). (→ Page 28)
▶
If required, reset the maintenance interval. (→ Page 30)
▶
Install the front casing.
▶
Fill out the relevant Service Record section in the Bench-
mark Checklist.
Installation and maintenance instructions ecoTEC pro 0020209589_04