Static overlay

Energy bills have been increasing. There are still ways to reduce this.

Adjust your combi boiler flow temperature for increased efficiency

Adjusting a combi boiler is much easier as you can simply set the lowest boiler flow temperature that keeps the home warm. Flow temperature is the temperature of the water running through your radiators, pipework and system.

There are advanced design calculations that can help determine the flow temperature, however for this technique we set the boiler flow temperature to 55 degrees, which virtually guarantees condensing efficiency savings.

From this 55 degree flow temperature set-point, 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 set-point works for most of the year except very cold days. For these colder winter situations, you find the temperature that works for the extremely cold days and use 55 degrees set-point for the remainder.

A small amount of trial and error is necessary without heatloss calculations or heatloss testing, for determining the flow temp. See below videos below showing you how to adjust the flow temperature. There is also a calculator for showing approx condensing boiler savings *See disclaimer below.

BrandModels / FamilyBoiler TypeVideo
MainHE, Eco HE, Eco, Eco EliteCombiVideo
IntergasRapid, HRE and ECO RFCombiVideo
VaillantEcotec Plus/ Exclusive Pre 2012CombiVideo
VaillantEcotec Plus/ Exclusive Post 2012CombiVideo
Worcester BoschGreenstar i ErpCombiVideo
DISCLAIMER: There is a note of caution, if your condensing pipe is terminating externally and has not been correctly installed or insulated properly, it may be more likely to freeze due to extra condensate produced by optimising the boiler for increased condensing mode. We cannot be held liable if your installation does not conform to latest regulations and your condense pipe freezes as a consequence of not being correctly installed or insulated.
Combi Boiler Condensing savings calculator

Disclaimer: Information on this website is provided for informational purpose therefore we cannot accept liability for subsequent problems. All repair tasks should be carried out by qualified trades people. We may also receive commission payments when you are taken to external websites and complete purchases from third party sellers, once you leave our site, we cannot be held liable for your purchases.