Help in wiring for Vaillant EcoMax

rkvohra70

Hello ,This is my first post here for help so please bear with me if this topic has already been discussed before

I have got Vaillant EcoMax 24k Combi boiler (no hot water tank )

I ahve bought a new wireless thermostat V3+,And my boiler or house dont have any kind of thermostat installed at the moment

Bit confused with wiring instructions from Tado so i am posting a picture of my boilers wiring and would appreciate if someone could put me in right direction about wiring

Tado auto instructions says i just need 3 core of the cable (out of 4 cores)and should ignore the black cable

and on the wireless reciever side i should make a loop between L and COMMON and the grey would go in CH NO

i am doubtfull about this wiring

can anyone suggest what i am suppose to do ?

I think gery and black cable should go in 3 and 4 at RT230V And then should go at Common and CH NO

PLEASE HAVE A LOOK AT THE PICTURE

Vaillant Ecomax.jpg

gabrielharrison

Hi,

You photo matches up with the Analog section of the Professional installers PDF for the wired smart stat (but not the extension kit), which may be helpful.

See, https://www.tado.com/start/manuals/st/Wired%20Smart%20Thermostat%20Manual.pdf

The Low Voltage Digital instructions for the Extension pack reference the same analogue connectors as the above manual.

See https://www.tado.com/start/manuals/st/Extension%20Kit%20Manual%20-%20Low%20Voltage%20Digital%20Installations.pdf

If you needs further assistance I would recommend using the chat support option on the main site https://support.tado.com/en/ They helped with exact info for my UFH and were great.

The full list of PDFs is here https://www.tado.com/all-en/professional-manuals

Gabriel

rkvohra70

The instructions say I should connect L,N and grey cables in 230v RT block
Normally L and N goes into existing boiler supply ,where boilers supply is connected
Never heard L and N goes into 230v RT block too

gabrielharrison

Hi,

If I understand correctly you are suggesting connecting it like page 7 of the manual https://www.tado.com/start/manuals/st/Extension%20Kit%20Manual%20-%20230V%20Relay%20Installations.pdf

Which number positions in you boiler photo are the Tado instructions saying L/N/G should go? Because the boiler end is switching 240v the Extension kit can simply pick up the live there, hence the link from L to COM on the kit.

Gabriel

rkvohra70

thanks

the instructions are saying

L should go at no 3

N should go at no 5

and GREY should go at no 4

gabrielharrison

Hi,

The Tado instructions are correct according to the EcoMax manual

See section 4.17.1 or 4.17.2 in https://www.vaillant.co.uk/downloads/z/ecomax/ecomax-use-installation-and-servicing-manual-261444.pdf

Gabriel

4.18.1 External electrical controls

The boiler terminals 3, 4 and 5 are for connecting external

electrical controls such as a programmer, room thermostat,

etc. Terminals 3 and 4 are linked together when

the boiler is supplied. If external controls are used, this

link must be removed, and the controls connected

across terminals 3 and 4. Terminal 5 is an additional

neutral connection for external controls.