Vaillant ecoTEC plus 940 40kW Combi Storage Boiler | 10036114

Description

The Vaillant ecoTEC plus 940 (0010036114) is a 40 kW storage combination boiler that pairs a wall-hung condensing boiler with an integral 15 litre shift-load cylinder. It delivers up to 40.8 kW of hot water output and a 21.0 l/min specific flow rate (18.0 l/min at ΔT 35 K), making it a strong fit for larger homes with high hot water demand and no space for a separate cylinder.

Central heating output is 5.0 - 32.3 kW at 50/30°C with up to 1:9 modulation, thanks to IoniDETECT combustion monitoring. The semi-touch interface includes a guided commissioning wizard, and the boiler is smart home ready when used with the myVAILLANT connect gateway accessory. It is ErP A rated for both heating and hot water, with NOx class 6 emissions of 26 mg/kWh.

It keeps the familiar case dimensions, footprint, flue position and pipe connections of the previous model for an easy like-for-like swap, and all major components are easy to reach for servicing. Up to 10 years of guarantee is available when registered on Vaillant Advance and installed with a Boiler Protection Kit.

40.8 kW

Maximum hot water output

18.0 l/min

Hot water flow at ΔT 35 K

15 litres

Integral shift-load cylinder

32.3 kW

Heating output at 50/30°C

A / A

ErP heating / hot water

1 : 9

Modulation

Installation and commissioning

Must be installed by a Gas Safe registered installer and commissioned using the Benchmark Commissioning Checklist: failing to install and commission to Vaillant's instructions and complete the checklist invalidates the warranty. The boiler is room-sealed only (C13, C33, C43, C53), is not suitable for outdoor installation, and in a room with a bath or shower must be in zone 2 or 3. Install a heating system filter and clean and treat the heating water.

Hot water flow explained

The headline 18.0 l/min at ΔT 35 K is the EN 13203-1 specific flow rate. Like all Vaillant combination boilers, the 940 is fitted with a flow regulator set for a 42 K temperature rise (14 l/min limiter) to keep showers comfortable in colder months, so real draw-off at the tap depends on incoming water temperature and the temperature you set. It needs at least 0.7 bar mains pressure and 2.0 l/min flow, and a maximum of 9.5 bar.

Limitations and compatibility

This model runs on natural gas only and is not LPG convertible. It cannot be used for multiple-flue configurations or cascades, or with directly connected wall-hung hot water cylinders. The new interface is not compatible with timeSWITCH 150 or 160. Vaillant senso controls and the VRC 700 work with it, and smart speaker integration is for single heating zones only. A spacer frame is not available for this model.

Gas supply sizing

Vaillant's range brochure lists a 22 mm gas inlet pipe size while the installation manual lists 15 mm at the boiler-side connection (supplied gas isolation valve). Size the gas pipework to BS 6891 for the maximum gas rate of 4.32 m³/h and confirm the meter can pass it.

What's in the box

Condensing boiler, 15 litre shift-load cylinder, wall mounting bracket, gas isolation valve, 3 service valves, connection pipes, 1 m condensate hose, a manual filling device with double check valve, a mounting template and documentation. Flue components and controls are ordered separately.

Key Features

Integral Storage for High Demand

The 15 litre shift-load cylinder with a cylinder charging pump helps the boiler meet simultaneous hot water demand. The unit rates three stars for total comfort factor (EN 13203-1).

IoniDETECT Combustion Monitoring

Intelligent gas combustion monitoring helps the boiler self-adjust to the gas quality and reach a wider modulation range for better efficiency.

Smart Home Ready

Add the myVAILLANT connect gateway for app control, smart speaker integration and remote support. LIN bus technology enables more accurate flow rate and pressure readings from the internal pump.

Semi-Touch Interface

An intuitive semi-touch interface with a step-by-step installation assistant speeds up first-time set-up and day-to-day operation.

Like-for-Like Replacement

The same 720 × 440 mm case, footprint, flue position and pipe connections as the previous ecoTEC plus storage combi keep swaps simple.

Built-In Protection

Frost protection starts the pump when boiler water falls below 12°C, an overheating safety shuts the boiler down before a lockout, and a condensate blockage safeguard stops it if the drain freezes.

Suitable For

Larger Homes

Properties with high hot water demand where a separate cylinder is not wanted.

No Room for a Cylinder

Sites where a combination boiler with integral storage avoids the need for a separate hot water cylinder.

Like-for-Like Upgrades

Replacing an existing ecoTEC plus storage combination boiler with the same footprint and connections.

Connected Heating

Homes using Vaillant senso controls or the VRC 700 with the myVAILLANT connect gateway.

Technical Specifications

General

Article number

0010036114

Gas Council number

47-044-96

Boiler type

Storage combination boiler (VUI 30/40CS/1-5)

Gas type

Natural gas only (not LPG convertible)

Dimensions (H × W × D)

720 × 440 × 580 mm

Dry boiler weight

60 kg (84 kg ready for operation)

Heat exchanger material

Stainless steel

Filling device

Manual filling device with double check valve

Heating

Heating output range, 50/30°C (condensing)

5.0 - 32.3 kW

Heating output range, 80/60°C

4.5 - 29.8 kW

Maximum heat input, heating

30.6 kW

Modulation (max / min)

1 : 9

Maximum flow temperature

85°C (factory setting 75°C)

Heating expansion vessel

10 l (pre-charge 0.7 bar)

Permissible operating pressure

2.5 bar

Nominal circulation volume at ΔT 20 K

1318 l/h

Condensate rate at 50/30°C

3.1 l/h

Condensate connection

19 mm

Hot Water

Maximum heat output for hot water

40.8 kW

Specific flow rate at ΔT 30 K

21.0 l/min

Flow rate at ΔT 35 K

18.0 l/min

Hot water temperature range

35 - 65°C

Shift-load cylinder capacity

15 l

Hot water expansion vessel

1.0 l (pre-charge 4 bar)

Minimum operating pressure / flow

0.7 bar / 2.0 l/min

Maximum DHW operating pressure

9.5 bar

Total comfort factor (EN 13203-1)

3 stars

Efficiency and Emissions

ErP class (heating / hot water)

A / A

ErP efficiency

94%

Efficiency at 30% load (G20)

109.2%

NOx class

6 (26 mg/kWh)

Sound power

49 dB(A)

Gas and Connections

Gas connection pressure (natural gas)

20 mbar (permissible 13 - 23 mbar)

Maximum gas rate (G20)

4.32 m³/h

Gas connection, boiler side

15 mm

Heating flow and return, boiler side

G ¾″ (22 mm pipe)

Hot and cold water connections

15 mm pipe

Air / flue connection

60/100 mm (80/125 mm connector available)

Flue

Flue classifications

C13, C33, C43, C53

Maximum horizontal flue, 60/100 mm

8 m

Maximum vertical flue, 60/100 mm

8 m

Maximum horizontal flue, 80/125 mm

28 m

Maximum vertical flue, 80/125 mm

30 m

Rear flue

Not available

Flue gas temperature, min / max

35 / 85°C

Electrical and Siting

Supply

230 V / 50 Hz (external fuse 3 A)

Maximum power, heating / hot water

98.5 W / 149 W

Standby power consumption

Less than 2 W

IP rating

IPX5D

Clearances

5 mm each side; 180 mm below; 500 mm in front for servicing (can be reduced if behind a door or panel that gives 500 mm when opened)

Frequently Asked Questions

Do I need a separate hot water cylinder?

No. The boiler includes an integral 15 litre shift-load cylinder and a 40.8 kW hot water output, so it supplies hot water on demand without a separate tank.

Can it run on LPG?

No. This model is natural gas only (category I2H) and is not LPG convertible.

What flue does it use?

The standard connection is 60/100 mm concentric (up to 8 m horizontal or vertical), with an 80/125 mm connector for up to 28 m horizontal or 30 m vertical. It is room-sealed only. If a terminal is less than 2.0 m from the ground, fit a terminal protection kit, and use Vaillant's own air/flue components.

Which controls and smart features work with it?

It works with Vaillant senso controls and the VRC 700 over eBUS, and the myVAILLANT connect gateway adds app control. The interface is not compatible with the timeSWITCH 150 or 160.

What mains water conditions does it need?

At least 0.7 bar mains pressure and 2.0 l/min flow, up to 9.5 bar. For water harder than 15°dH (267 ppm CaCO₃), consider softening or stabilising the water to protect the hot water system.

What guarantee is available?

Up to 10 years is available when the boiler is registered on Vaillant Advance and installed with a Boiler Protection Kit. Annual servicing by a qualified person is needed to keep the guarantee valid.

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Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

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