Recent content by Screwdriva

Viessman displays it's current modulation % on the boiler display screen and on the app.

Jury is still out on reliability as it's only been 9 months since installation but I have to say I have to share that I've observed the boiler run at 10% modulation when using the UFH, during which time our gas consumption was surprisingly low for the amount of heat that was being emitted. It...

Thanks for clarifying - I assumed 95% efficiency for the above calculation. And you kinda have to fit weather comp with the V200-W as it doesn't suggest or require any room influence (thermostats), another area of savings. Any idea what the Alpha's modulation ratio and minimum output is? Can...

I'm probably too late to this but thought I'd share experiences of our Viessmann 200-W. In short, we upgraded from a 5 year old 18 kW Greenstar Ri. Normally, we wouldn't have replaced a newer condensing boiler but we were installing a few retrofit efficiency upgrades simultaneously (wet UFH...