Vaillant ecoTEC Plus 438 Boiler Instruction Manual

Manual Vaillant ecoTEC Plus 438 Boiler Instruction Manual

Vaillant ecoTEC Plus 438 Boiler Instruction Manual

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Vaillant ecoTEC Plus 438 Boiler

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Vaillant ecoTEC Plus 438 Boiler Instructions

Here we offer the Vaillant ecoTEC Plus 438 Boiler manual completely free and in English. We have cataloged this manual in the Boilers section on Manualverse, and it has been rated by 1 users with an average rating of 5. If you have any specific questions about Vaillant ecoTEC Plus 438 Boiler, we suggest checking the Frequently Asked Questions (FAQs) section of this manual.


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Vaillant ecoTEC Plus 438 Boiler Specifications

Description Unit ecoTEC plus 438
Maximum CH heat input (net) kW 38.4
CH heat output (80/60 °C) kW 6.3 - 38.0
CH heat output (50/30 °C) kW 6.8 - 41.0
SEDBUK Band A
SAP Seasonal Efficiency % 90.8
NOx Class 5
"lP rating" IPX4D
Inlet gas working pressure required (natural gas) mbar 20
Gas supply (G20) Gross CV (s.t.) MJ/m3 37.8
Maximum gas rate M3/h 4.06
Minimum gas rate M3/h 0.71
Burner % CO2 (Case on) % 9.0 + 0.2 - 0.5
Gas connection (compression) mm 15
Water connections (compression) mm 22
Condensate drain (internal diameter) mm 19 min.
Fuse ratings fan supply PCB A 3.15 AT
Main PCB A 125 mAT
Minimum flow rate of water through the boiler L/min. 27.2
Weight kg 3.3
Electrical supply V~/HZ 230/~50
External fuse A 3
Power input W 60
Case height mm 600
Case width mm 375
Case depth mm 334

Vaillant ecoTEC Plus 438 Boiler Details

The Vaillant ecoTEC Plus 438 is a wall-hung, open-vent condensing boiler designed to provide efficient central heating for open-vented or sealed water systems. It arrives fully tested and assembled, ensuring reliability straight out of the box. Its compact dimensions make it suitable for installation on any internal wall, offering flexibility for various property types and sizes.

This boiler features a built-in diagnostic system that provides key information on its operational status, aiding in both commissioning and any necessary fault finding. This intuitive system helps installers quickly understand boiler performance, ensuring optimal efficiency. The data badge is conveniently located on the combustion chamber cover for easy reference.

The ecoTEC Plus 438 is designed to function with a standard flue system, available in 100 mm or 125 mm outside diameters. For enhanced installation flexibility, various flue extensions, 90° bends, and 45° elbows are available. This adaptability ensures that the boiler can be integrated into diverse property layouts, even those with complex flue requirements.

A notable feature is its integrated frost protection programme. This system automatically activates the burner and system pump when the internal boiler temperature drops to 3°C, safeguarding against freezing, provided both electricity and gas supplies remain active. For extended periods of severe weather with power interruptions, draining the system is recommended.

The boiler is supplied factory-set for Natural Gas (G20) but can be easily converted for use with LPG (Propane G31) by a competent person. This versatility makes it suitable for a wider range of properties, including those not connected to the main gas grid. Safety is paramount, with strict regulations regarding gas installation and servicing.

For enhanced control, the ecoTEC Plus 438 supports a range of optional Vaillant easy-fit controls, including programmers and room thermostats. If fitted with a Vaillant uniSTOR unvented cylinder and relevant controls, the domestic hot water temperature can also be adjusted directly on the boiler, offering precise comfort management.

It includes provisions for water make-up and can be connected to unvented hot water cylinders, such as the Vaillant uniSTOR range. All unvented cylinders must be installed by a competent person in compliance with current building and water regulations. The boiler also incorporates a safety valve for sealed systems, preset to a 3-bar lift pressure.

An internal 75mm trap ensures proper condensate drainage, which is periodically discharged by siphonic action. The condensate drain pipe should ideally connect to the internal household drainage system, though external connections to soakaways are also possible, with careful consideration for freezing conditions.

For system longevity, the manual emphasizes the importance of flushing the heating system, especially in existing installations, and using inhibitors suitable for stainless steel heat exchangers. Regular maintenance and servicing are strongly recommended – typically once a year – to ensure continued safe and efficient operation and to maintain the warranty.

Frequently Asked Questions (FAQs)

Can't find the answer you need? Here are some frequently asked questions about the Vaillant ecoTEC Plus 438 Boiler, and we answer them below.


What is the primary function of the Vaillant ecoTEC Plus 438 Boiler?
The ecoTEC Plus 438 is a wall-hung open-vent condensing boiler designed to provide central heating for fully pumped open-vented or sealed water systems.

Can this boiler be installed in any room of the house?
Yes, it can be installed in any room, including bathrooms (zones 2 and 3), but specific electrical and safety regulations must be observed, especially concerning switches and controls.

Does the ecoTEC Plus 438 have built-in frost protection?
Yes, it features a built-in frost protection program that activates the burner and system pump when the internal temperature falls to 3°C, provided both gas and electricity supplies remain on.

Is the boiler compatible with external controls like room thermostats?
Yes, it is recommended to control the boiler with a programmer and room thermostat. Vaillant offers a range of optional easy-fit controls that can be connected.

What type of gas does the boiler use?
The boiler is supplied factory-set for Natural Gas (G20) but can be field-adjusted by a competent person for use with LPG (Propane G31).

How often should the boiler be serviced?
For continued safe and efficient operation, it is recommended that the boiler be checked and serviced at regular intervals, generally once a year.

What happens if there's a gas leak or fault?
If you smell gas or suspect a leak, immediately turn off the gas supply at the meter, open windows and doors, warn others, do not use electrical switches or naked flames, and evacuate the house before contacting your gas supplier or a competent person.

Can I adjust the domestic hot water temperature on the boiler?
The domestic hot water temperature can only be adjusted on the boiler if it is installed with a Vaillant uniSTOR unvented cylinder and relevant Vaillant controls.

What does the 'plume' from the flue terminal mean?
The plume is a visible emission of water vapour from the flue terminal, which is normal for high-efficiency condensing boilers and indicates correct operation, especially in wet or damp weather.

What should I do if the condensate drain becomes blocked?
If the boiler stops working due to a blocked condensate drain, which might be caused by ice in freezing conditions, you can try releasing the blockage with warm cloths on the pipe. If the fault persists, contact your installation/servicing company.

What are the maximum clearances required around the boiler for servicing?
Minimum operational and servicing clearances must be provided; for example, 5mm from side surfaces, 600mm above, 200mm below, and 150mm in front of the boiler for servicing access.

Does this boiler come with a warranty?
Yes, Vaillant provides a full two-year parts and labour warranty for this appliance, subject to correct installation and commissioning by a competent person.

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