Do you have a question about the Vaillant THERMOcompact 624/2 E and is the answer not in the manual?
Covers safe installation, setup, adjustments, and handling gas leaks.
Recommends annual servicing and signing a service agreement for optimal performance.
Details the manufacturer's commitment to rectifying defects within 24 months of installation.
Identifies and describes the operating controls for the TURBOmax Plus boiler.
Identifies and describes the operating controls for the THERMOcompact boiler.
Explains the multi-function boiler display and indicator lights for status and fault codes.
Explains how to reset the boiler after ignition failure or other faults, including lock-out codes.
Lists common issues like failure to operate or lack of heating, with initial checks.
Covers safe installation, setup, adjustments, and handling gas leaks.
Recommends annual servicing and signing a service agreement for optimal performance.
Details the manufacturer's commitment to rectifying defects within 24 months of installation.
Identifies and describes the operating controls for the TURBOmax Plus boiler.
Identifies and describes the operating controls for the THERMOcompact boiler.
Explains the multi-function boiler display and indicator lights for status and fault codes.
Explains how to reset the boiler after ignition failure or other faults, including lock-out codes.
Lists common issues like failure to operate or lack of heating, with initial checks.
This document provides instructions for the Vaillant TURBOmax Plus 824/2 E, 828/2 E, and THERMOcompact 615/2 E, 620/2 E, 624/2 E, 628/2 E boilers, covering their operation, safety, and maintenance.
The Vaillant TURBOmax Plus and THERMOcompact boilers are designed for use in central heating and hot water supply systems. They are built to meet the latest technical specifications and safety regulations, ensuring reliable and efficient performance.
The TURBOmax Plus model offers both central heating and instantaneous domestic hot water. It automatically supplies hot water whenever a tap is opened and adjusts its operation to meet both heating and hot water demands in the most economical way. This boiler maintains an internal temperature of approximately 40°C when the warmstart system is activated, providing hot water almost instantly. When the warmstart is off, a short delay may occur before hot water is delivered.
The THERMOcompact model provides central heating and domestic hot water when integrated with a separate indirect hot water cylinder. Unlike the TURBOmax Plus, it does not offer instantaneous hot water directly from the boiler but relies on the external cylinder for hot water storage and supply.
Both boiler types feature an advanced multi-function display that shows the water temperature in the boiler circuit during normal operation. In case of a fault, the display will show a specific fault code, aiding in troubleshooting. The boilers are equipped with a frost protection function that automatically activates if the heating water temperature drops below 5°C, heating the boiler circuit to approximately 30°C to prevent freezing. This function, however, requires the main switch to be in the "ON" position and the boiler to be connected to the electrical supply.
An anti-cycling economiser control is incorporated into both models to prevent energy-wasteful ON and OFF operation during central heating mode, ensuring more efficient use of energy.
To operate the boiler, users first need to ensure that the cold water service valve, heating flow and return service valves, and the gas service valve are open. The pressure gauge on the boiler indicates the water content in the system, which should be within the green band (1 to 1.5 bar). If the pressure falls below 0.8 bar when cold, the system needs refilling.
The main ON/OFF control allows users to switch the boiler on or off. When turned to the "I" position, the boiler is active.
For TURBOmax Plus users, the domestic hot water temperature can be adjusted using a dedicated control knob. Turning it clockwise increases the temperature, while turning it anti-clockwise decreases it. For normal use, the one o'clock position is recommended. In hard water areas, it's advised not to set the control knob above the mid (12 o'clock) position to prevent excessive scale formation. The warmstart function, unique to TURBOmax Plus, can be activated by turning the hot water temperature control knob all the way to the right for a short time until the green indicator light illuminates. To deactivate it, turn the knob all the way to the left.
For central heating, the maximum radiator temperature control knob adjusts the heating supply temperature. Recommended settings vary with the season: left for spring/autumn, middle for mild winter, and right for cold winter. External controls like room thermostats and thermostatic radiator valves should be set according to their specific instructions. The boiler will then operate automatically to provide central heating.
In the event of a "Lock out" fault (indicated by a red light and fault code F.28 or F.29), users can attempt to reset the appliance by pressing the "Reset" button for approximately 1 second. If the boiler repeatedly shuts off after three attempts, professional assistance is required. A fault code F.22 indicates insufficient water in the system, requiring refilling before the boiler can resume operation.
To turn off central heating only (summer mode) on a TURBOmax Plus, the maximum radiator temperature control knob should be turned all the way to the left. The boiler will still provide domestic hot water. To turn off both central heating and hot water for short periods, the main ON/OFF control should be set to "0". For longer periods or when there is no risk of frost, it is recommended to also turn off the gas supply, cold water service valve, and electrical supply.
For THERMOcompact users, turning off central heating involves turning the maximum radiator temperature control knob all the way to the left. It's important not to turn off the THERMOcompact boiler if a hot water cylinder is incorporated and hot water is still needed. To turn off the boiler for short periods, the main ON/OFF control should be set to "0".
The boiler display also provides status codes (e.g., S.00 for "No heating required," S.04 for "Burner ignited," S.34 for "Frost protection mode") which can be accessed by pressing the "i" information button. These codes are useful for understanding the boiler's current operational state, especially during maintenance.
Regular maintenance is crucial for the longevity and efficient operation of the boiler. The outer casing should be cleaned with a damp cloth and mild soap, avoiding abrasive or solvent cleaning agents that could damage the plastic fittings or case.
An annual service by a competent person is strongly recommended. Users can arrange this with their service agent or Vaillant Ltd. The Benchmark Log Book, completed by the installer, should be handed to the user and contains important information about the boiler's installation and commissioning.
In case of a gas smell or suspected leak, immediate safety measures include turning off the boiler, avoiding electrical switches, refraining from smoking, turning off the gas supply at the meter, ventilating the room, and contacting the gas supplier or a competent person.
No modifications should be made to the boiler, gas, water, or electrical supply, flue system, safety valve, or any structural changes around the appliance that could affect its operational safety.
For troubleshooting, if the boiler fails to operate, users should check if the gas and water supplies are on, if there is enough water in the heating system, if the electrical supply is on, if the main ON/OFF control is in the "ON" position, and if the burner lock-out indicator light is illuminated. If hot water operates but central heating does not (TURBOmax Plus only), users should check if heating is turned on and if all external heating controls are active. If problems persist, contacting the installer or Vaillant Service Solutions is advised, quoting any displayed fault codes.
| Output | 24 kW |
|---|---|
| Energy Efficiency Class | A |
| Warranty | 2 years |
| Type | Combination boiler |
| Fuel Type | Natural Gas |











