Viessmann Vitomax HS M73 User Manual (English)

Other manuals for Viessmann Vitomax HS M73

Questions and Answers:

D
David WhiteAug 15, 2025
What to do if the burner does not start in my Viessmann Vitomax HS M73 Boiler?
- J
  Jeffrey BeasleyAug 15, 2025
  If the Viessmann Boiler's burner doesn't start, first check if the mains isolator is switched ON to ensure voltage is present. If the burner fault indicator is illuminated, press the reset button on the burner control unit. Also, verify the fuel supply line for any obstructions and check the shut-off valves. Finally, examine the safety equipment, in case the safety chain has been activated.
V
Vickie Hayes MDAug 18, 2025
Why is my Viessmann Vitomax HS M73 Boiler discharging from the safety valve?
- M
  Morgan ParkerAug 18, 2025
  If the Viessmann Boiler's safety valve is discharging, verify that the discharge pressure matches the maximum permissible operating pressure; replace the safety valve if required. Inspect the pressure regulator and pressure limiter adjustments, correcting them if the operating pressure is too high. Clean the valve seat if it's contaminated, and clear any blockages in the water trap pipe.
K
Karen SloanAug 21, 2025
What to do if the water level limiter switches off in my Viessmann Boiler?
- N
  nicholas24Aug 21, 2025
  If the water level limiter switches off on your Viessmann Boiler, open the shut-off valve in the feedwater line. Also, check the mains water connection to ensure there is feedwater in the feedwater tank. You should also determine the cause of the damage to the water pump and water level controller in accordance with the installation instructions.
C
Christy CooperAug 25, 2025
How to lower the flue gas temperature in my Viessmann Vitomax HS M73?
- S
  sanchezjaimeAug 26, 2025
  If the flue gas temperature is too high in your Viessmann Boiler, clean the boiler to address any contamination on the flue gas and water sides that may be reducing heat transfer. Also, check the burner heating output to ensure that the rated boiler heating output is not exceeded.
T
Taylor StewartAug 28, 2025
Why does the water level limiter keep switching off on my Viessmann Vitomax HS M73 Boiler?
- C
  Catherine LyonsAug 28, 2025
  If the water level limiter switches off and you notice severe water level fluctuations in your Viessmann Boiler, drain water from the boiler and feedwater tank, then refill with treated water. Blow down more frequently, and check the water treatment system. Also, check and adapt the electrode length.
R
Roberto RoseAug 31, 2025
How to fix high water level in my Viessmann Boiler?
- C
  Corey PowersAug 31, 2025
  If the water level is too high in your Viessmann Boiler, install a steam trap to ensure the steam distributor above the boiler is adequately drained. Additionally, check the electrode length, in case the water level is set too high.
G
Gail PopeSep 3, 2025
How to prevent oxygen corrosion in my Viessmann Vitomax HS M73 Boiler?
- J
  Justin GallowaySep 3, 2025
  To prevent oxygen corrosion on the water side of your Viessmann Boiler, check the water treatment system and injection system in accordance with VdTÜV guideline if you are topping up with unsuitable water. If the boiler is often taken out of service without being preserved, switch to standby (95 °C) instead of a complete shut down.
C
Carol AllenSep 7, 2025
Why is there steam knocking in my Viessmann Vitomax HS M73 Boiler's condensate container?
- W
  Willie WilliamsSep 7, 2025
  If you hear steam knocking inside the condensate container or feedwater tank of your Viessmann Boiler, install or clean the check valve (observe the flow direction) because the check valve in the feedwater line might be missing or faulty. Identify and repair any faulty steam trap in the system. Reduce steam pressure, as U-bends might buckle.
R
Renee SuttonSep 12, 2025
What causes steam hammer inside a Viessmann Boiler?
- T
  Todd CollinsSep 12, 2025
  If there's steam hammer inside your Viessmann Boiler, connect the feedwater line to the correct connector, ensuring that feedwater is fed in at the feedwater connector.

Viessmann Vitomax HS M73 Specifications

General

Brand	Viessmann
Model	Vitomax HS M73
Category	Boiler
Language	English

Summary

Safety Instructions

Safety Instructions Explained

Explains safety symbols and their meanings to prevent accidents and losses.

Target Group

Defines the intended audience for the operating instructions.

Regulations to be Observed

Lists applicable national and statutory regulations for installation and operation.

Safety Instructions for Working on the System

Provides crucial safety guidelines for maintenance and repair tasks on the boiler.

Auxiliary Components, Spare and Wearing Parts

Emphasizes using only genuine Viessmann spare parts for safety and warranty.

Dismantling and Disposal

Outlines procedures for safe dismantling and disposal according to environmental regulations.

Safety Instructions for Operating the System

Covers essential safety practices for daily system operation and potential hazards.

Information

Symbols

Explains various symbols used throughout the manual for clarity and safety.

Designation of Boiler Types

Describes how boiler types are indicated and their meaning.

Intended Use

Defines the specific applications and limitations for the boiler system's operation.

Systems with Operating Temperatures > 110 °C

Details requirements for boiler systems operating above 110°C, including compliance directives.

Functions

Installation Overview

Provides a diagram illustrating the boiler system components and their layout.

Level Electrodes (10 to 12)

Explains the function of level electrodes for water level control and safety.

Maximum Water Level (HW Electrode 11)

Describes the function of the high water level electrode for overfill protection.

Lowest Water Level (NW Electrode/LWL 12)

Explains the function of the low water level electrode for water shortage protection.

Safety Valve (20)

Details the function and testing requirements of the safety valve for overpressure protection.

Air Vent Shut-off Valve (21)

Describes the optional air vent shut-off valve used during filling.

Steam Shut-off Valve (22)

Explains the function of the main steam shut-off valve for isolating the boiler.

Blow-down (25 and 26)

Details the procedure for periodic removal of deposits from the boiler.

TDS Unit (27 and 28)

Explains the function of the TDS unit for salt content checking and regulation.

Water Level Indicator (40)

Describes the visual and direct water level indication system.

Pressure Monitoring Unit (41 to 44)

Explains the components of the pressure monitoring system for boiler safety.

Sample Cooler (46)

Details the use of the sample cooler for water analysis.

Shutdown and Preservation

Steps to Shut Down the Boiler

Provides a step-by-step guide for safely shutting down the boiler system.

Dry Preservation

Outlines the process for dry preservation of the boiler system for longer idle periods.

Wet Preservation

Explains the procedures for wet preservation, including using oxygen binders.

Preservation with Sodium Sulphite

Details the method for preserving the boiler using sodium sulphite.

Physical-Technical Preservation Measures

Describes physical methods for boiler preservation, including pressure and flow.

Treating the Flue Gas Side

Provides instructions for cleaning and preserving the flue gas side of the boiler.

Preservation in High Humidity Areas

Advises against dry preservation in areas with high relative humidity.

Information on Maintenance

Outlines requirements for correct maintenance and use of authorized companies.

Preventing Excessive Flue Gas Temperatures

Discusses causes and remedies for high flue gas temperatures affecting efficiency.

Water Quality

Standard Values for Water Quality

Lists recommended water quality standards for optimal boiler performance and longevity.

Raw Water

Discusses the suitability of raw water for boiler feedwater and the need for treatment.

Top-up Water

Details the importance of monitoring top-up water in the feedwater supply.

Condensate Return

Explains the procedure for returning condensate to the feedwater tank.

Water Treatment System

Covers the requirements for chemical and thermal water treatment systems.

Saline Boiler Feedwater Requirements

Specifies permissible operating pressures and water quality parameters for saline feedwater.

Conditioning

Explains the aims and methods of chemical treatment for feedwater and boiler water.

Salt-Free Feedwater Requirements

Details quality requirements for salt-free feedwater, including conductivity and acid capacity.

Adjusting Alkalinity and Oxygen Binders

Covers methods for adjusting alkalinity and using oxygen binders for boiler water.

Stress Corrosion Cracking and Conditioning Deviations

Discusses causes and prevention of stress corrosion cracking and deviations during conditioning.

Sampling Water and Steam

Provides guidelines for sampling water and steam for quality analysis.

Sample Analysis and Test Equipment

Details procedures for sample analysis and the necessary test equipment.

Recommended Testing Parameters and Standards

Lists recommended parameters and corresponding standards for water quality testing.

Commissioning

Recommendation for Commissioning

Outlines approvals, signatories, and procedures required before commissioning the boiler.

Preparations for Commissioning

Details essential checks and requirements before the initial boiler startup.

Commissioning the Control Panel

Details checks for the control panel, fuses, individual functions, and displays.

Commissioning the Feedwater Pumps

Outlines steps for filling, starting, and checking the feedwater pumps.

Filling the Boiler with Feedwater

Specifies checks required before and during the boiler filling process.

Adjusting Water Level Control

Explains how to adjust stepped and constant water level control systems.

Checking the Water Level Limiter

Details the procedure for checking the functionality of the water level limiter.

Commissioning the Burner

Covers requirements and steps for commissioning the boiler burner.

Safety Pressure Limiter Function Check

Explains how to check the function of the safety pressure limiter.

Safety Valve Function Check

Details how to check the safety valve's set pressure and blow-off capacity.

TDS Controller Adjustment

Details the procedure for adjusting the TDS controller settings.

Checking Water Side Closures

Covers the checks for tightness and retightening of water side connections and flanges.

Commissioning After Boiler Idle Time

Outlines the procedure for restarting the boiler after a period of inactivity.

Boilout, Report, and Instructions

Information on boilout, logging commissioning data, and operator training.

Monitoring

Recommendation for Monitoring

Provides guidance on monitoring intervals based on user specifications and regulations.

Testing Intervals

Specifies the frequency for routine checks and tests performed by the operator and contractors.

Operator's Log

Details what information should be recorded in the operator's log for inspections and maintenance.

Handling Operating Faults

Advises on immediate actions and hazard prevention in case of operating faults.

Repairs and Inspection

Maintenance

Covers general requirements and safety precautions for performing repair and maintenance work.

Working on the Boiler System

Emphasizes safety procedures when working on pressurized and hot boiler system components.

Safe Inspection of the Steam Boiler

Provides recommendations and safety measures for conducting inspections inside the steam boiler.

Inspections

Outlines proposed intervals for external, internal, and repeated pressure tests for the system.

Commissioning, Inspection, and Maintenance

Steps Overview

Lists the steps for commissioning, inspection, and maintenance activities with corresponding page numbers.

Commissioning the System

Details the procedure for the initial startup and operational checks of the boiler system.

Shutting Down the System

Provides safety precautions and steps for safely shutting down the boiler.

Removing the Burner

Explains the procedure for removing the burner from the boiler.

Opening the Boiler Doors

Details how to open and close the boiler doors.

Removing Inspection Port Closures

Describes the process for safely removing inspection port covers.

Removing and Cleaning Turbulators

Details the procedure for removing and cleaning turbulators within the boiler.

Cleaning Heating Surfaces

Outlines the process for cleaning the boiler's heating surfaces and flue gas collector.

Cleaning Economiser Heating Surfaces

Describes how to clean the economiser heating surfaces.

Checking Flue Gas Side Gaskets

Details the inspection of gaskets and packing cords on the flue gas side.

Cleaning the Sight Glass

Explains how to clean the boiler's sight glass.

Checking Thermal Insulation and Gaskets

Describes the inspection of thermal insulation components and gaskets.

Inserting Turbulators and Closing Boiler Doors

Details the process of inserting turbulators and closing the boiler doors securely.

Closing and Securing Inspection Ports

Provides instructions for closing and securing the boiler's inspection ports.

Checking Water Chamber for Deposits

Details the procedure for draining, cleaning, and checking the water chamber for deposits.

Checking Water Side Connections for Tightness

Outlines steps for checking and ensuring the tightness of water side connections.

Checking Tightness of Inspection Ports

Guides on checking the tightness of inspection ports, including gasket replacement.

Checking Water Level and System Pressure

Describes checks for the water level and the system's operating pressure.

Checking Safety and Control Equipment

Details the inspection of safety devices and control systems for proper function.

Checking the Safety Valve

Explains the procedure for checking the safety valve's operation and set pressure.

Checking Water Quality

Guides on documenting water quality parameters like top-up volume and hardness.

Checking Thermal Insulation

Covers the inspection of the boiler's thermal insulation.

Checking Installation Room Ventilation

Details the inspection of the ventilation system in the boiler room.

Checking Flue Pipe Tightness

Outlines the procedure for checking the flue pipe for leaks.

Adjusting the Burner

Details how to adjust the burner output and discusses low-NOx burner operation.