Combi boiler with Drayton LP20RF & DIGISTAT+RF - upgrading to programmable or smart thermostat

FreeBear

Surely best to take the opportunity to fit a system that's fully compatible, to squeeze out that extra, ooh, 5% or so more efficiency? (Some suggestions of 10+% more.)

My boiler (a Viessmann 050) returns around 85% efficiency with basic on/off control. Using the OpenTherm interface along with a smarter thermostat that can call for a lower output, I can get the efficiency up to ~94%. Average efficiency over the heating season is lower (probably 90-92%), but still worth doing.

If you are using a lot of gas for heating, an extra 5% is worth having. If you can get it up to 10%, even bigger savings.

WIAWSNB

Since EMS is a Bosch thing, I guess you'll have to go for it. I'd give them a Chat, Grumpy - see what will fit.

grumpy_codger

https://forums.moneysavingexpert.com/discussion/comment/82140378#Comment_82140378

I will. Thanks

ic

Bosch EasyControl is the native EMS compatible controller. Fancy display, app controlled, weather compensation, and has a range of TRVs and sensors available too.

grumpy_codger

https://forums.moneysavingexpert.com/discussion/comment/82140840#Comment_82140840

Thank you, but…

COMPATIBLE GREENSTAR BOILERS††

Combi

Greenstar i Junior**

Greenstar i

Greenstar Si Compact

Greenstar CDi Compact

Greenstar CDi Classic†

Greenstar Highflow CDi

And it's wired directly to the boiler, i.e. in the simplest case has to be close to it and for temperature in other places relies on smart TVRs, correct?

grumpy_codger

Just for the record…

My boiler is in fact 30Si, not 308i, i.e. from Si Compact range. So, it is compatible with EasyControl (that I don't like anyway).

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/82141838#Comment_82141838

I'd need to check, but I assume the EasyControl has a WiFi receiver that you wire to the boiler, and then the 'programmer' is a separate unit that is positioned where you want to detect the room temp - say the living room.

If it has App control as IC suggests, then it should do everything you want, and almost certainly be the best bet for your boiler.

Strongly suggest you ask WB - get the full spec from them. If it turns out it doesn't give you what you want, eg App Control - then you can sacrifice the EMS part, and choose the system of your choice.

Have you tried any - Hive, Nest, Tado, whatevs?

grumpy_codger

https://forums.moneysavingexpert.com/discussion/comment/82142395#Comment_82142395

Yes, it does exist -

Newer boilers have special slot for it - https://www.worcester-bosch.co.uk/files/Bosch_EasyControl_.pdf . Mine doesn't have it.

AI:

If you have the older Worcester Greenstar 30si (Standard Mechanical Slot)If your 30si features a large square or rectangular slot on the front fascia meant for an old mechanical clock (like the MT10) or older digital timers: 

• The slot cannot be used for the EasyControl receiver: The modern wireless RF Key will not fit physically or communicate electronically with this slot. 
• How to install instead: You must install the Bosch EasyControl CT200 via a hardwired 2-core cable directly connected from the thermostat wall mount to the boiler's low-voltage EMS/BB bus terminals. 
• Handling the slot: If a receiver or clock is currently plugged into that front panel slot, it should be removed or completely disconnected so it does not conflict with your new smart thermostat. You can leave a blanking plate over the empty slot.

Have you tried any - Hive, Nest, Tado, whatevs?

What do you mean by 'tried'?

I looked briefly and pretty much any smart thermostat can be connected.

ETA: however, I do consider wired EasyControl as well now.

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/82142425#Comment_82142425

That's what I meant - I couldn't find a wireless WB EMS that would directly fit your boiler.

So, that info is saying that their CT200 - connected using only two wires - will connect to the interweb, and provide Smart App control too? And you are also saying that you'd be 'happy' to go wired to this controller? Where would you fit it - which room? (Edit: you seem to be correct - it'll do what you want. At £166 at PlumbNation, not excessively costly either.)

If so, then I would strongly suggest this for max efficiency.

Yes, pretty much any other 3rd-party Smart device will also work, but will not provide the same level of boiler efficiency. So, it looks as tho' your choice is to go CT200 for max benefits but the inconvenience of wires, or go elsewhere for max convenience with the loss of some efficiency.

By 'tried', I mean have you used any so know what they are like? Do you have a fav?

grumpy_codger

I'd say 'reluctantly happy'. And as ATM I don't think I'll ever use smart TVRs (I hate batteries), higher efficiency is questionable. The most likely position is the landing or the corridor on the first floor.

I was happy with my old Honeywell Lyric TR6-HW, the same TR6 is now the main contestant: