Vaillant ecoTEC exclusive 843 User Manual (English)

Other manuals for Vaillant ecoTEC exclusive 843

Questions and Answers:

P
pereztimothyAug 20, 2025
How to fix a Vaillant Boiler that won't start, resulting in no hot water and cold heating?
- B
  Bobby SalinasAug 20, 2025
  To fix a Vaillant Boiler that isn't starting, resulting in no hot water and cold heating, consider these steps: * Ensure the gas isolator cocks are open. * Check that the cold water stop valve is open. * Verify the power supply by checking the fuse. * Confirm the boiler is switched on. * Adjust the heating flow and hot water temperatures. * If the system pressure is low (F.22), fill the installation. * If there is air, have the system purged. * For fault F.28 after failed ignitions, press the reset button and if it persists after three attempts, consult a professional.
C
Charles BarrettAug 25, 2025
Why is my Vaillant ecoTEC exclusive 843 not igniting and showing fault code F.28?
- H
  Henry CooperAug 25, 2025
  If your Vaillant Boiler is not igniting and displays fault code F.28 after three unsuccessful attempts, press the reset button for one second to initiate another attempt to ignite the flame. If the ignition fault persists after three reset attempts, it is recommended to consult a competent person.
J
Jacqueline PierceAug 28, 2025
Why my Vaillant ecoTEC exclusive 843 Boiler doesn't start and shows fault message F.28?
- H
  Heather DavenportAug 28, 2025
  If your Vaillant Boiler doesn't start and displays fault message F.28, it indicates that the product switched to fault mode after three unsuccessful ignition attempts. To resolve this, press the fault clearance key for one second to initiate another ignition attempt. If the issue persists after three attempts, it is recommended to consult a qualified technician.
D
Dr. Bethany Brandt DVMAug 31, 2025
Vaillant ecoTEC exclusive 843 Boiler not starting: how to troubleshoot no hot water and cold heating?
- B
  Brandon ThompsonAug 31, 2025
  If your Vaillant Boiler isn't starting, and you're experiencing no hot water and cold heating, here's how to troubleshoot: First, check that both the on-site gas isolator cock and the product's gas isolator cock are open. Also, make sure the cold water stop valve is open. Verify the building's power supply by checking the fuse. Ensure the product is switched on. Check that the heating flow and hot water temperatures aren't set too low. If the system pressure is insufficient (F.22), fill the heating installation. If there's air in the system, have it purged. Finally, if fault F.28 appears after three failed ignition attempts, press the reset button and consult a professional if the issue persists after three resets.
B
beth22Sep 4, 2025
What causes a Vaillant ecoTEC exclusive 843 Boiler to fail to start, resulting in no hot water and heating remaining cold?
- C
  campbelldanielleSep 4, 2025
  A Vaillant Boiler might fail to start, resulting in no hot water and cold heating, due to several potential causes. These include: 1. Closed gas isolator cocks (on-site and/or on the product). 2. A closed cold water stop valve. 3. A disconnected power supply in the building. 4. The product being switched off. 5. Heating and/or hot water temperatures set too low. 6. Insufficient system pressure (low water pressure, indicated by fault message F.22). 7. Air in the heating installation. 8. The product entering fault mode after three unsuccessful ignition attempts (fault message F.28).
C
Casey ThomasSep 8, 2025
What to do if my Vaillant ecoTEC exclusive 843 Boiler does not start, with no hot water and cold heating?
- S
  Scott OsborneSep 8, 2025
  If your Vaillant Boiler doesn't start, resulting in no hot water and cold heating, several factors could be the cause. First, check if the gas isolator cocks (both on-site and on the product) are open. Also, ensure that the cold water stop valve is open. Verify that there is power supply to the building by checking the fuse. If the power supply is okay, make sure the boiler is switched on. It's also possible that the heating flow temperature or hot water temperature is set too low; adjust accordingly. Finally, insufficient system pressure or air in the heating installation might be the issue. In the first case you need to fill the heating installation. In the second case you should contact a qualified technician to purge the heating installation.

Vaillant ecoTEC exclusive 843 Specifications

General

Boiler Type	Condensing
Fuel Type	Natural Gas
Efficiency	94%
ERP Rating	A
Dimensions (H x W x D)	720 x 440 x 338 mm
Mounting	Wall-mounted
Warranty	5 years
Heating circuit	Single