The tragic reality of energy independence!

Screwdriva

Reed_Richards said:

Yes, and that is what will get you close to your 98% efficiency.

Modulation down to 2 kW is only necessary when your heating demand is 2 kW.  That's 48 kWh per day (or less if the heating is off at night).  In my house 48 kWh per day would have been about my average heat & HW energy usage in April this year and  mid October to mid November last year(based on my electricity use and assuming I got a CoP of 3).   

It all comes together. 2kW modulation will occur only if the heat loss is reduced (hence the triple glazing) and heating demand allows for it. We will likely not require heating till November but the real test here is to see if all these improvements can come together to keep the boiler running in this modulation sweet spot in the winter months.

Early indications are good - using our DHW consumption as a proxy. I have another thread on this and will continue to update it.