Can Smart Thermostat replace my poorly located old-style programmer?

ChaunceyGardiner

grassmarket said:

CG - thanks for that explanation. But now that you’ve mentioned Ethernet connections - I’m really confused! Do you mean that in the Tado setup, a device/gateway is physically connected to the router, with all the other devices communicating with it via radio? If so - what’s physically connected to the boiler & how do I communicate with it? Do I communicate with gateway via Wifi & then gateway communicates with boiler device via radio? 

All we’re looking for is a way to control our CH/HW programmer (currently in the garage) without having to go outside to do it - other than drilling a big hole in the wall & relocate the programmer inside the house. Is a smart thermostat a reasonable way to solve that problem?

As for Tado, OpenTherm etc - I neither want nor don’t want them. I just want some advice about what I should have in my setup to make it work right.

Yes, it works as you describe. The bridge is connected to the internet. You control the system using your phone, tablet, computer, smart speaker etc via the bridge. The wireless receiver, connected to the boiler in place of the old programmer, responds to commands from the bridge for heating and hot water.

Tado, or almost any smart thermostat, would be ideal for your situation. I don't have any experience of OpenTherm, but it allows the boiler to modulate its output, according to demand. With a relay system, it's on, at maximum power, or off.

[Deleted User]

grassmarket said:

CG - thanks for that explanation. But now that you’ve mentioned Ethernet connections - I’m really confused! Do you mean that in the Tado setup, a device/gateway is physically connected to the router, with all the other devices communicating with it via radio? If so - what’s physically connected to the boiler & how do I communicate with it? Do I communicate with gateway via Wifi & then gateway communicates with boiler device via radio? 

All we’re looking for is a way to control our CH/HW programmer (currently in the garage) without having to go outside to do it - other than drilling a big hole in the wall & relocate the programmer inside the house. Is a smart thermostat a reasonable way to solve that problem?

As for Tado, OpenTherm etc - I neither want nor don’t want them. I just want some advice about what I should have in my setup to make it work right.

Tado has its own ‘bridge’  which plugs into your router. 

https://uk.shop.tado.com/products/internet-bridge-1

The Tado control app and any smart thermostats connect to this bridge. I have two smart thermostats which are both battery powered and have a 2 wire link to the boiler. My hot water reheating is controlled by a separate programmer/controller.

If you want Tado to do both heating and hot water control then you need the Tado extension kit which will replace your existing controller in the garage. 

https://support.tado.com/en/articles/3403673-in-which-cases-do-i-need-a-wireless-receiver-or-an-extension-kit

Without seeing a picture if what you have at the moment, it is difficult to give specific advice. Have a look at the Drayton Wiser website as this offers a simple faceplate controller replacement using your existing wiring.

BUFF

grassmarket said:

Buff - thanks for your input; unfortunately I don’t understand most of it! Modulation? 

Perhaps I should investigate the Vaillant options, as suggested by Dolor. 

Modulation is where your boiler tailors it's burn/output to the demand rather than simply running full blast all the time. So when you need a lot of heat e.g. a cold start it will run at high output but if you only need a little heat to maintain an already achieved temp it will only run at a low level. It is more energy efficient than/saves energy consumption compared to bursts of heat at max output..

In order to do this most modern boilers will have some internal sensors & routines.
However, to further improve upon that you want sensors/controllers that are external to the boiler & that can directly communicate with the boiler & essentially take over control of the modulation rather than just sending an on/off signal to the boiler - this will usually result in further savings,  typically of perhaps~5%.
Opentherm is 1 such communication protoco (originally developed by Honeywell, a 3rd party controls supplier) that was an attempt to have an industry standard that was cross-compatible rather than everybody being locked into having controls from the boiler manufacturer because 3rd party controls could not communicate with their boilers. (in reality there is enough wiggle room in the Opentherm spec. that some boiler manufacturers can still make it difficult even though nominally Opentherm compliant). 

As I mentioned earllier, 3 big boiler manufacturers (Vaillant, Viessmann & Bosch group incl. Worcester) have their own equivalent but individual proprietary communications protocols in at least some of their boilers & don't natively support Opentherm. They usually have a hardware solution as Opentherm compatibility is required by law in NL so they need it to sell boilers there but they don't have to support those solutions in the UK which can lead to warranty implications as Dolor mentioned.  

It is certainly worth investigating whether your particular boiler can use Opentherm without an adapter.
If it can't, investigate the cost of Vaillant's own compatible controls that do what you want.
Compare that with the cost of a Drayton Wiser 2 Zone system, work out how long it would take to recover the additional cost of the Vaillant (I am assuming theirs would be dearer but if your existing thermostats are already Vaillant it may not be) from increased savings.

p.s. a reminder that as of July 2022 an energy-saving controls upgrade will be zero-rated for VAT on labour & materials
https://www.legislation.gov.uk/uksi/2022/361/made#:~:text=This Order introduces a temporary,2022 until 31st March 2027.

Magnitio

Agree with @[Deleted User] . Have a look at Wiser. I have fitted Wiser, Tado and Netatmo for relatives and Wiser sounds like best solution for you, and depending on existing controller, could be an easy installation.

[Deleted User]

As said above, all modern boilers modulate their output. One particular Veissman model has a modulation ratio of 17:1. This just means that a boiler say of 24kW can perform as if it was a 4kW boiler when heating demand reduces. This reduces boiler cycling.

More explanations here:

https://www.draytoncontrols.co.uk/news/opentherm-explained