Vaillant ecoTEC Plus 620 System Boiler is a wall-mounted gas system boiler with a 20kW nominal output. Designed to provide central heating in a sealed system, it works with a separate hot-water cylinder, making it an option for homes that need stored hot water rather than a combi boiler’s on-demand arrangement.
The current ecoTEC plus 620 specification lists a 1:9 modulation ratio and a nominal heat-output range of 2.8–21.2kW at 50/30°C in condensing mode. Vaillant describes the range as smart-home ready when paired with its compatible internet gateway. Check the exact appliance variant, installation requirements and available warranty with the supplier before ordering.
20kW System Boiler
Natural Gas
1:9 Modulation
Hot-Water Cylinder Required
At a Glance
Boiler Type
System
Separate hot-water cylinder required
Nominal Output
20kW
ecoTEC plus 620 model
Modulation
1:9
As specified by Vaillant
Energy Rating
ErP A
As listed for the product
What Is a System Boiler?
A system boiler heats water for the central-heating circuit and works with a separate cylinder to store domestic hot water. Unlike a combi boiler, it does not heat domestic hot water instantly within the boiler. The wider system design determines the hot-water storage, controls and other components required.
Applications & Suitability
The ecoTEC Plus 620 may suit a property whose heating system has been designed around a 20kW-class system boiler and a separate hot-water cylinder. Boiler output should be selected based on a competent assessment of the property’s heat demand—not household size alone. Check the full appliance specification, existing system and cylinder compatibility with a qualified heating engineer before choosing a replacement.
Important Installation Guidance:
Gas boiler installation and commissioning must be completed by a Gas Safe registered engineer in accordance with the current manufacturer instructions and applicable requirements. Confirm the flue, controls, system components and warranty conditions for the exact model supplied.
Key Features
20kW Nominal Output
A system-boiler model in Vaillant’s ecoTEC plus range. Have the output checked against the property’s calculated heating requirements.
1:9 Modulation
The stated modulation ratio allows the boiler to vary its output across a range to better match heating demand.
Cylinder-Based Hot Water
Works with a separate compatible hot-water cylinder. Cylinder size and recovery performance depend on the wider system design.
Smart-Home Ready
Vaillant lists smart-home connectivity when used with its compatible internet gateway and controls. Check accessory and control compatibility before purchase.
Wall-Mounted Format
The wall-mounted design can be considered for replacement or new installations where the available space and connections are suitable.
Stainless-Steel Heat Exchanger
Vaillant’s current specification lists a stainless-steel heat exchanger for the ecoTEC plus 620.
Key Specifications
| Product |
Vaillant ecoTEC Plus 620 System Boiler |
| Product Code |
0010036011 |
| EAN |
4024074906613, as supplied |
| Brand |
Vaillant |
| Boiler Type |
System boiler |
| Fuel |
Natural gas; confirm any conversion options for the exact model |
| Nominal Output |
20kW model designation |
| Nominal Heat Output Range at 50/30°C |
2.8–21.2kW (condensing mode) |
| Nominal Heat Output Range at 80/60°C |
2.5–19.8kW (non-condensing mode) |
| Modulation Ratio |
1:9 |
| Flow Temperature Range |
30–85°C |
| Energy Rating |
ErP A, as supplied |
| Heat Exchanger |
Stainless steel |
| Installation Format |
Wall mounted |
| Hot-Water Cylinder |
Required; selected separately |
| Warranty |
The supplied listing states up to 10 years subject to conditions; verify the current offer, installer eligibility and required protection kit with Vaillant or the seller |
Who Is This Boiler For?
This boiler is for homeowners, landlords and heating professionals considering a system boiler with a separate hot-water cylinder. It may be relevant for a replacement or new system where the property’s heat loss, cylinder arrangement, fuel supply and controls have been assessed and are compatible.
Installation & Warranty
1
Check the heating requirement: Ask a qualified heating engineer to assess the property and confirm the correct boiler output and system configuration.
2
Confirm cylinder and control compatibility: Check the hot-water cylinder, controls, flue arrangement and system components against the current Vaillant documentation.
3
Verify warranty conditions: The advertised warranty may depend on the installer, registration, protection kit and other terms. Confirm eligibility and the exact duration before purchase.
Frequently Asked Questions
Does the ecoTEC Plus 620 include a hot-water cylinder?
No. It is a system boiler designed to work with a separate compatible hot-water cylinder, which is selected separately.
What is the boiler’s modulation ratio?
Vaillant lists a 1:9 modulation ratio for the ecoTEC plus 620.
Is the boiler suitable for every large home?
Not automatically. The boiler should be selected using a heating-demand assessment and checked against the property’s system and hot-water requirements.
Can it connect to smart controls?
Vaillant describes the range as smart-home ready with a compatible internet gateway and controls. Check accessory compatibility for the specific setup.
How long is the warranty?
The supplied product description advertises up to 10 years subject to conditions. Warranty offers can depend on the installer, registration and required accessories, so confirm the exact terms with the seller or Vaillant before ordering.
A 20kW System Boiler for Cylinder-Based Heating
The Vaillant ecoTEC Plus 620 is a wall-mounted 20kW system boiler with a listed 1:9 modulation ratio, designed to work with a separate hot-water cylinder. Confirm the boiler’s suitability for the property, compatible system components and current warranty conditions with a qualified installer and the supplier before purchase.
