Ideal Vogue 32kw boiler, Honeywell Evohome jiggerypokery, Honeywell bloke is trying to sell me an additional OpenTherm bridge at an extra £90. Apparently it forms an intimate relationship with your boiler rather than just talking to it like the normal bridge would.
What’s it all about?
Is it worth it?

£90 is a fair price for the part. OpenTherm is worth it if your boiler supports the interface properly, as it allows the thermostat to vary the water temperature flowing through the system.

Beware, however – there are some reports of incompatibility between some boilers and the Evohome OpenTherm bridge. These seem to be linked to hot water temperature, so if you don’t have a combi boiler you’ll be fine.

If I had an OpenTherm compatible boiler, I’d have the bridge installed (full Evohome installation here).

Still don’t understand what it does, on the OpenTherm website it seems to just say that it is a new communications protocol, but then doesn’t really explain what sort of advanced communications it does and/or how it benefits you. The list of advantages to the end user are spurious and read like they’re really struggling to think of anything and savings claims don’t give any detail.
On top of that, Honeywell want me to buy a £200 starter pack and then a separate £90 OpenTherm bridge, then throw away half of the starter pack as it’s made redundant by the OpenTherm bridge, pah! 😡 .

its better to heat your home by running the radiators/underfloor heating for longer at a lower temperature. The boiler works more efficiently and the house temperature is more stable (and thus comfortable). Even better is to use weather compensation (is taking account of the outside temperature). The best way to do this is to vary the flow temperature from the boiler.

A standard boiler interface from a thermostat is just an on/off call for heat. Open therm allows flow temp control. Two considerations – value of extra comfort and payback period on the extra £90. Suspect it’s some years.

So far as I can tell opentherm is the protocol (language in my terms). The honeywell kit speaks honeywell and switches the boiler via a relay. With the bridge, it translates the honeywell speak into something that your boiler can understand(opentherm), allowing a greater degree of control.
That’s my take from it anyway.
Compensated flow is a common strategy, and it can be effective but you will need an outside air temperature sensor. As for what is the most efficient method of heating your home; it depends very much on your home.

The Evohome controller doesn’t talk to outside temperature sensors – you can add one, but the data is ignored. Instead it pulls the temperature from an online weather service.

Is this vogue a combi bouler or system boiler as you can have opentherm on the system boiler.