Modulating Gas Boiler and Smart Thermostat

[Woggle]

Hi there,

We've got a fairly old(ish) boiler installed in 2012 - a Worcester Bosch Greenstar Ri: https://www.plumbase.co.uk/link/1/h016641_28413_t.pdf

Manual seems to suggest it's a modulating boiler presumably using the EMS bus language.

I've been researching about modulating vs on-off and in looking into smart thermostats want to install something which is modulating ideally with advanced weather compensation.

I can't though work out compatability - it looks like it's definitely not compatible with the Worcester Wave. I'm getting different results on compatibility with the Worcester EasyControl.

And then the two other options I'm looking at - Tado and Nest using the OpenTherm Bus language.

Can anyone help on compatibility - and any thoughts on the preferred smart thermostat?

Obviously the downside with the Worcester EasyControl (if it is compatible) is that it is going to probably restrict me if I replace the boiler at some stage.

Thanks!

 

[flameport]

OpenTherm is supposed to be an open standard, so devices from one manufacturer will work with those from someone else.
However certain manufacturers have chosen to implement it in different incompatible ways, so the reality is that some devices do not work with others, and even those that do may not work in the way you want or expect.

Options:
Buy the boiler and controls from the same manufacturer at the same time, so they will work properly. That means a 100% new installation.
For anything else, don't bother. The savings between using it or not are insignificant.

 

[Woggle]

Interestingly, just had a response from Worcester Bosch:

"As a regular heat only boiler the RI will be typically installed on a zoned system to provide heat to the heating/cylinder circuit. These systems are wired to provide a 230vac switched demand to the boiler and so the Bosch Easy / Worcester Wave would not be compatible as they cannot be connected directly to the appliance. Third party smart thermostats are compatible with the system but these would need to be wired to create a 230vac switched demand that control the zone valves rather than working off an EMS/open-therm protocol."

Is it worth going ahead do you think with a 3rd party option using switched demand (which presumably means on/off?).

 

[vulcancontinental]

OpenTherm is supposed to be an open standard, so devices from one manufacturer will work with those from someone else.
However certain manufacturers have chosen to implement it in different incompatible ways, so the reality is that some devices do not work with others, and even those that do may not work in the way you want or expect.

Options:
Buy the boiler and controls from the same manufacturer at the same time, so they will work properly. That means a 100% new installation.
For anything else, don't bother. The savings between using it or not are insignificant.

All true but what do you class as insignificant and where did the data come from? I am being slightly mischievous but you may have come across something I haven't seen,

 

[flameport]

It was a few percent, and from a report published several years ago around the time that the Boiler Plus thing was introduced.
Not new information.

 

[TeaAndBiscuits]

OpenTherm is supposed to be an open standard, so devices from one manufacturer will work with those from someone else.
However certain manufacturers have chosen to implement it in different incompatible ways, so the reality is that some devices do not work with others, and even those that do may not work in the way you want or expect.

Options:
Buy the boiler and controls from the same manufacturer at the same time, so they will work properly. That means a 100% new installation.
For anything else, don't bother. The savings between using it or not are insignificant.

The Ideal Vogue (and probably other models) modulates and uses opentherm to communicate with their own Touch (or its successor the Halo) control.

Problem is, those controls are total crap. Well the Touch is, no personal experience of the Halo but I would be surprised if it's not also crap.

Nest works perfectly with it though and is 100x better functionally.