Im interested in fine turning my ecoTEC plus 630 boiler - specifically D.0 CH (30) and D.77 HW (30) part load, D.19 pump config (2) and thoughts on D.78 HW flow temp (80C) plus any other boiler teaks numbers in brackets are current settings. The system is the 630 with VR65 + VR10 charging a Gledhill Stainless Lite Indirect 300 ltr cylinder with 25kW primary. CH is via rads / towel rails and thermostatic rad valves with a potential load of 27kW HW has priority. The heat loss calcs with 20% margin for intermittent heating and -1 outside temp is 21kW.
I have just swapped my VRC430 for a Nest 3 / OpenTherm / VR33 solution that appears to fully modulate the boiler in CH mode between 75C (upper limit adjustable in Nest app) and 35C the lowest I have seen so far. Its rare to see the boiler in anti-cycle mode. Its been around -1 to 0C outside today and the flow temp has varied 38 to 42C ish for a stable 18C room temp. It will be mid 50s C this evening for 20C room temp. Nest 3 uses the Vaillant dual control feature for HW demand and the flow temp is set by D.78 - currently 80C (default).
The rads are all balanced and bled etc and the system works well way more responsive now with the Nest 3. This really is fine tuning + a bit of fun and curiosity.
I have just swapped my VRC430 for a Nest 3 / OpenTherm / VR33 solution that appears to fully modulate the boiler in CH mode between 75C (upper limit adjustable in Nest app) and 35C the lowest I have seen so far. Its rare to see the boiler in anti-cycle mode. Its been around -1 to 0C outside today and the flow temp has varied 38 to 42C ish for a stable 18C room temp. It will be mid 50s C this evening for 20C room temp. Nest 3 uses the Vaillant dual control feature for HW demand and the flow temp is set by D.78 - currently 80C (default).
The rads are all balanced and bled etc and the system works well way more responsive now with the Nest 3. This really is fine tuning + a bit of fun and curiosity.