Tado HW Immersion Heater Relay

Munezz

hi Tado gang,

I have 6kw solar system on the roof without batteries and i would like to heat water using immersion heater during the day when we are at work , instead of exporting electricity back to grid.

I am currently considering 2 options.

1 . Myenergi Eddi

2 As i already have some tado devices for heating. I am wondering if i could make a very simple system for Hot Water where Tado Extension Recevier triggers the 3rd party Relay that will just give power to my 150 Litres Vølund qmc 150 with an immersion heating element ( 1 kW/230 V or 3 kW/400 ). My heater has built in thermostat so, i am not worying about overheating and etc. I really want something very basic that will will give 230 to the boiler or not by setting the Time Blocks in the Tado App.

Tado support just says what is states on their website : Tado is not supporting immersion heaters. But i am wondering why NOT if there is a HW relay in the extension kit ( ok, it is not rated to 1 2 3 kw ) but why can not it trigger bigger relay ?

Did anyone make similar simple diy system ? please suggest the relay or contactor i can buy. I really want to controll it from Tado Receiver, so i can use tado app. I know there are other cheap things on the market , but they will have their own app which i do not want.

Thanks

davidlyall

There’s no reason why you can’t use the extension kit output to switch a contactor (relay) to switch the higher load of the immersion. A competent electrician should be able to easily manage that

I assume you don’t need that to control hot water heating from a boiler

Munezz

Hi David,

Thanks for your reply, it gives me even more confidence. You are right I am not currently interested in controlling boiler ( in my case it is Diesel Boiler , Live in Denmark ). This is currently working ok and heating that water tank as it should. The whole point is to divert excess solar panel generation to the immersion heater of that tank ( it is dual, CH Coil and Immersion heater ) . Additionaly, in summer time i would be happy to turn off diesel boiler completely, therefore i need that immersion heater functionality.

Obviously solar panel generates during the day and my plan is to create a schedule in Tado for a day time to turn on Immersion and my calculations are that it would be enough hot water for evening shower and following morning.

I would be also happy to do it myself as most of similar things i do myself, but in this case i want to ask exact model and brand of a relay that people think will suit to my needs.

I have 2 options now :

1. Tado controlls 230v relay that will turn on 1kw 230 immersion. Calculator says it needs 8h to heat 150l from 10 to 60c
2. Tado controlls 3 phased relay that will give 3kw to the immersion, this will make the heating faster but will probably export some electricity from the grid . Which is also fine.

I am ready for either options. Just need a direction to an exact relay ( ideally din rail type, so i can hide it in the el box )

Thanks

davidlyall

No problem

I think you'll need advice that complies with Danish electrical standards (I'm in the UK). Hopefully someone on here can advise but you may need to seek local advice on suitable products

Munezz

In UK, what would you buy , David ? I have spent 5 years in Liverpool studying and 9 years working in London : ))

davidlyall

https://www.theunderfloorheatingstore.com/contactor-25a-2no-230v-50hz?referrer=googleproductad

This might be OK for your needs for the 240V heater

I've no idea about 3 phase as it's extremely rare to have it in residential properties over here

Munezz

Thank you ! David !!!

Munezz

Hi again, could anyone please suggest how do i wire wireles receiver with hot water control to contactor ? Contactor requires some voltage to operate. While Tado hot water relay just closing the circuit, how i could make it "live" ? i think tado says max 30 volts and 3 amps on hot water tabs. What does bridging LIVE to COM does ? I need something that once i turn ON hot water in tado APP . Wireless receiver clicks and supply some voltage to contactor. Thanks

davidlyall

I'm not familiar with the wireless receiver but assuming it's the same as the older extension kit, it will support 240V on the terminals for relay switching of the HW circuit.

So, I assume you'd just provide the contactor with a permanent live and the switched live would come from the wireless receiver terminals

Munezz

Hi and thanks . I just wanted to update this post as i have managed to make it work is i wanted. For people who has diesel boiler and wood boiler and 150 liter electric hot water tank which can not be controlled by tado, i can confidently say it is success.

So, i have two dumb boilers ( just for convenienience, i use whichever i like to use, depend on my mood ) , i have 150l electric hot water , 6 kWp solar panels and , water UFH in three rooms ( out of 6 ).

What i did , i ordered from UK wireless receiver with Hot Water control. I have placed SRT on all radiators and on UFH manifold ( 3 pieces ) . Obviously i have separate temperature sensors in these rooms.

I have bridged both relays on tado wireless receiver so that when they are "ON" it gives 240v , if you connect positive to NO contact and neutral to neutral.

The CH relay is just connected to my water pump in the UFH manifold, so that it only works when the system is calling for heat. The HW relay is connected to SIEMENS contactor , that triggers it and power goes to 3 phased 150liters water tank ( hot water ).

What this system gave me, i have one system which is TADO that controlls pretty much everything without extra third party components. My SRT working as everybodys else and UFH manifold also controlld by that. I have UFH pump that is NOT running 24/7 and only turns on when system is calling for heat. And my main thing is that i can schedule my HOT water tank to use my solar generation power during peak sun ( 10 to 4 for now ) and NOT straight after we take a shower 6 in the morning. 150L tank is enough for me and my wife for two showers and teeth brush in the evening and two shower and teeth brush in the morning, then tank reheats.

P.s boilers are working as a dumb, they are just heating water in 3000 liters acuumulation tank until they reach set temperature. Then separate pump is pumping that water.

Happy days !