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Smart Heating part 1: choosing boiler and thermostat

Heating is very important part of home. You have to maintain optimal temperature for maximum comfort at home. With this in mind, while renovating home I have redone all the heating system with a modern one. Now there is underfloor water heating in basement and first floor, radiators in the second floor and garage. New boiler, water heater and all the pipes and accessories.

This is a part 1 of a 4-part blog series.

The biggest challenge was, that in my smart home I want to control every element of heating system remote, by phone, watch and by voice.
First of all, had to choose gas boiler.
Mainly there was 3 major brands to choose from for me: Viessmann, Buderus, Junkers.
Viessmann has the biggest price tag if the boiler has capabilities for some automation.
Junkers is the simplest boiler with no smart automation integrated. And the Buderus is in the middle of two of them. All other parameters of competing models of these 3 brands are almost the same. Maybe it is just some of marketing stuff about the gas burners and their efficiency.
Viesmmann with automation capabilities has too high price tag, as almost the same functions and parameters are present in significantly cheaper Buderus model. With this in mind I have bought Buderus Logomax Plus GB172i-24 gas boiler.

As this boiler can be controlled by EMS bus, I was recommended to buy Bosh CT100 thermostat for remote control of boiler.

This nice looking, modern thermostat indeed is smart. It can turn on the boiler, you can set desired temperature on schedule. Bosh CT100 thermostat can control hot water tank on schedule and the desired temperature of hot water running from water taps. You even can schedule thermal disinfection of water system from the phone. It has geo-fencing feature – it can turn off heating at home when you leave ant turn on when you came back. I have used it for several weeks, but had to returned it, because it can control only one room temperature and did not work not only with HomeKit, but with no other home automation platform.

I want to be able to regulate temperature in every room separately. While researching how to do this, I found some interesting systems. One which seemed very promising – Danfoss Link™.

It has almost everything what I needed: capability of multi zone heating control, wireless radiator valves, underfloor heating control, wireless thermometers for rooms, app for the phone. But it does not have Apple HomeKit support and central console with screen. The screen on it seems like from the past century. And I had no plans this kind of screen only for heating system anywhere. Nowadays you don’t need dedicated central console with screen for one system control. And the price of the whole system is above 1000euros. Too high, no go.

Alsmost the same goes for Honeywell Evohome.

Big plus for honeywell, that they can control hot water temperature and scheduling of water tank. But no HomeKit support for heating system is no go.
While reserching on web for smart thermostat, I found that underfloor heating + radiators valves control with HomeKit support can be done with Tado or Netatmo thermostats.
Tado has nice looking thermostat and radiator valves.

What I liked from Tado is that room thermostat and radiator valves measure not only temperature, but also the humidity. Did not liked that you have to touch radiator valve or room thermostat to see current temperature of room. And I somehow missed that Tado can control water tank heating.

With my previous heating system, I had used one Netatmo thermostat for old boiler control. And now they have nice looking radiator valves. Thermostat and radiator valves has always on e-ink display – you can clearly see current room temperature on it.

I accepted that Netatmo can’t control hot water tank (will leave it to boiler for now) and decided to stay with Netatmo. When I started to look how can I add multiple rooms control for my home it seemed it is very easy to do, but when I started to install underfloor heating control things got a little bit complicated, but with the help of automation specialist the solution was found. In the next part you will find how to connect smart thermostat to boiler.

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