asalcedo wrote:
I have installed two new Worcester 30 CDi system boilers at home. (They
work in tandem, at the same time, as if they were one unit)

According to the user's manual, under "Tips for Energy Conservation",
if the property has TRVs and room thermostats (which is my case), the
boilers should be set at the maximum temperature setting and use the
thermostats and TRVs to regulate the temperature as needed in each
room.

I certainly agree that that arrangement gives the most flexibility.
However, based on my reading of condensing boilers, the most condensing
and thus, the highest efficiency is achieved at 55 degrees Celsius.

If I set the boilers to the maximum the boiler's water reaches about 92
degrees.

If I use a 5 setting, 7 being the maximum, the boilers' water is about
62 degrees and still gets the house warm enough (at least now that it
is not too cold outside)

What is then the most energy efficient setting?

Thanks,

Antonio




We have a tandem system at our church (Keston 40s) and I was told by the
installer that the temperatures should be set so that one ts the 'lead'
boiler, coming on first with the other set a degree or so higher. From
cold both come on, but when maintaining temperature, only the lead
boiler comes on. I was also advised to switch lead boilers at intervals
(presumably to even out the wear)

Malcolm