Adjust your combi boiler flow temperature for increased efficiency

Adjusting a combi boiler is much easier as you can simply set the lowest flow temperature that keeps the home warm. This basically the temperature of the water running through your radiators, pipework and system. There are advance design calculations that can help determine the flow temperature, however for this technique we go to the flow temperature of 55 degrees, which virtually guarantees condensing savings. From there if you are not getting the home warm, you can increase by 1-2 degrees at a time, let the system run for a day and then repeat as necessary.

You may find that 55 degrees works for most of the year except very cold days. For this you find the temperature that works for the extremely cold days and use 55 for the remainder. A small amount of trial and error is necessary without heatloss calculations and testings, for determining the flow temp. See below for condensing boiler savings and videos below showing you how to adjust the flow temperature. *See disclaimer below.