Why is there a water shortage and a large temperature spread between flow and return probe in my Vaillant ecoTEC exclusive 838 Boiler?
A water shortage with a large temperature spread between the flow and return probe in your Vaillant Boiler might be caused by a blocked or defective pump, low pump output, or the flow and return sensors being swapped over. Contact the service team for assistance.
What to do if the water pressure is too high in my Vaillant Boiler?
If the water pressure in your Vaillant Boiler exceeds 2.9 bar, you should check and adjust it to the correct level.
What to do if the flame goes off during operation and subsequent ignition attempts failed in my Vaillant Boiler?
If the flame goes off during operation and subsequent ignition attempts fail in your Vaillant Boiler, it could be due to the gas supply being temporarily stopped, the ignition transformer having a spark failure, or faulty earthing of the appliance. Contact the service team for assistance.
General| Boiler type | Condensing |
|---|---|
| Mounting | Wall-mounted |
| Output | 38 kW |
| Efficiency | 94% |
| ErP Rating | A |
| ERP efficiency | 94% |
| Warranty | 5 years |
| DHW output | 38.0 kW |
| Fuel | Natural gas |
| Type | Combination boiler |
Instructions for the plant operator regarding document retention.
Explanation of symbols used in the manual for danger and required actions.
Specifies the part numbers for which this installation manual is applicable.
Information on directives and standards the appliance complies with.
Provides gas council numbers for specific appliance models.
Location of the appliance's identification plate.
Diagram and legend of the functional elements of the ecoTEC exclusive appliance.
Summary table of appliance types, designated countries, gas types, and heat ratings.
General information on observing safety instructions and warning notes.
Specifies the correct and incorrect uses of the Vaillant ecoTEC boiler.
Provides crucial safety instructions and regulations to be observed.
Procedure to follow in case of a gas leak detection.
Procedure to follow in case of flue gas detection.
Precautions to prevent corrosion to the unit and flue installation.
Measures to prevent frost damage during power cuts or low temperatures.
Guidance on using an emergency power generator for heating.
Warnings about using incorrect tools causing material damage.
Prohibits changes to specific boiler components and surroundings.
Specific instructions for operating the boiler with liquid gas.
Regulations for installing the boiler in rooms below ground level.
Warning against using incorrect gas types and its consequences.
General prerequisites for installing and commissioning the appliance.
Checklist for verifying completeness of delivered appliance and accessories.
Manual handling regulations and recommendations for lifting and moving the appliance.
Instructions and recommendations for safely unpacking the appliance.
Guidelines for positioning the appliance, considering weight and clearance.
Instructions for positioning the appliance above worktops with obstructions.
Guidelines for positioning the appliance within restricted compartments.
Instructions for positioning the appliance in a roof space, including risk assessment.
Diagram showing appliance dimensions and connection points with measurements.
Requirements for selecting the installation location, including safety and environmental factors.
Diagram illustrating required clearances around the appliance for installation.
Step-by-step instructions for mounting the boiler onto the wall bracket.
Procedure for safely removing the front casing of the appliance.
Important safety caution regarding flushing the heating system before connection.
Detailed instructions and safety warnings for connecting the gas supply line.
Procedure for connecting the hot and cold water pipes, including safety warnings.
Instructions for connecting the heating flow and return pipes, including safety warnings.
Instructions for fitting the pressure relief valve and filling loop.
Safety warnings and instructions for fitting the air/flue gas duct.
Details and availability of the 100mm standard flue pipe.
Information on the optional 125mm concentric flue pipe system.
Guidelines for positioning flue terminals to ensure safety and prevent issues.
Recommendations for air connection and ventilation requirements for enclosures.
Instructions for connecting the condensate drain pipe and suitable termination points.
Safety warnings and instructions for connecting the appliance to the electrical supply.
Details on the factory-fitted connection cable and plug requirements.
Instructions for connecting external controllers and accessories to the boiler's electronics.
Information on connecting external controllers like timers or room thermostats.
Diagram and instructions for connecting an external timer to the boiler's connection rail.
List of optional Vaillant timers and accessories with their item numbers and connections.
Diagrams illustrating electrical connections for various components and accessories.
Instructions for filling the heating system.
Guidelines for treating heating water to prevent corrosion and ensure compatibility.
Procedure for filling the boiler and heating system and venting air.
Instructions for flushing the entire heating system before boiler startup.
Procedure for filling and venting the hot water side of the system.
Instructions for filling the condensate siphon to prevent flue gas escape.
Procedure for checking the gas setting and ensuring correct operation.
Checking flue gas system integrity and recirculation for safety.
Procedure for measuring and verifying the boiler's gas flow rate.
Procedure for checking the gas inlet working pressure at the reference test point.
Steps to check the overall function of the boiler's heating and hot water systems.
Procedure to check the heating function and status codes.
Procedure to check the hot water function and status codes.
Instructions for flushing the system after reaching operating temperature.
Instructions for handover, including controller settings, safety, and maintenance advice.
Guide to navigating and setting various diagnostic parameters on the appliance.
Table listing adjustable parameters, their meaning, and default settings.
Instructions for setting the heating partial load using diagnosis point 'd.0'.
Adjusting pump overrun time for heating operation and different modes.
Setting the maximum feed temperature for the heating system.
Changing temperature regulation from feed to return for underfloor heating.
Adjusting the burner anti-cycle time to prevent frequent switching.
Setting the appliance's maintenance interval and how the service signal is displayed.
Adjusting the pump output in five steps for optimal system performance.
Instructions for adjusting the bypass valve to regulate pressure.
Details on required inspection and maintenance frequency and safety warnings.
General guidelines for inspection, maintenance, and use of genuine spare parts.
Crucial safety warnings regarding electrical shock and proper procedure before maintenance.
Procedure for measuring CO2 concentration to check combustion performance.
Step-by-step guide for adjusting CO2 concentration using the main throttle screw.
Table detailing specific inspection and maintenance activities and their frequency.
Procedures for filling and draining the heating system.
Refers to Section 6.1 for filling the appliance and heating system.
Procedure for closing maintenance cocks and opening drain valves.
Steps for draining the entire heating system, including radiators.
Introduction to servicing the compact thermal module.
Safety warnings and procedure for dismantling the compact thermal module.
Instructions and safety precautions for cleaning the heat exchanger.
Procedure for checking the burner for damage and replacement.
Safety instructions for reassembling the Thermo-Kompaktmodul.
Safety warnings and procedure for removing and cleaning the secondary heat exchanger.
Instructions for cleaning the condensate trap and refilling it with water.
Procedure for checking the pressure in the expansion vessel.
Reference to Section 6.2.3 for checking gas inlet working pressure.
Reference to Section 8.1.3 for checking the air figure (CO2 concentration).
Checks to perform after completing any inspection or maintenance task.
Guide to obtaining error codes (F.xx) and status codes (S.xx) for troubleshooting.
Explanation of status codes displayed by the appliance indicating operating conditions.
Instructions for accessing and navigating diagnosis levels for parameter adjustment.
List of error codes displayed by the appliance when faults occur.
Instructions for accessing the appliance's error memory.
Details on various test programs (P.0-P.6) for checking appliance functions.
Procedure for resetting all adjustable parameters to their factory default settings.
Essential safety warnings regarding electrical shock and proper procedure before component replacement.
Safety warnings and step-by-step instructions for replacing the burner.
Safety warnings and instructions for replacing the fan or gas fittings.
Safety warnings and procedure for replacing the primary heat exchanger.
Instructions for replacing electronics or display, including setting appliance variant.
Recommendation for arranging a Maintenance Agreement with Vaillant Service Solutions.
Guidelines for disposing of the appliance and packaging responsibly.
Comprehensive table of technical specifications for the ecoTEC exclusive models.
Document detailing the appliance's compliance with relevant EU directives and standards.
To Next Page