Weather compensation | What is weather compensation?

You may have seen weather compensation mentioned on my site, but what exactly is it you ask? Well weather compensation is a smart little gadget that alters the temperature flowing though your radiators to suit the outside temperature. This makes the system more energy efficient, economical and gives greater comfort levels.
Most condensing boilers have wc capabilities, the product itself is just a thermistor (a cross between a thermostat and resistor) that measures temperature, when the temp changes so does the resistance in the thermistor which enables the boiler to know what the actual outside temp is and adjust the amount of gas and heat used to warm your radiators.

"Yes but I have a thermostat doesn't that do the same job" you ask? Well actually no it doesn't, even the latest smart stats such as nest do not have this capability, they cannot directly control the flow temperature of your boiler all they can do is adjust your actual room temperature. Your boiler will still be running at the temp set on the boiler stat usually 70-80degs.

The thing is when a heating system is designed it is usually done to cope with the coldest days of the year around -3degs,
but the majority of the time temperatures are much higher at around 8-15degs when heating is still needed but the full output of your radiators isn't. So what this little outside sensor does is speak to the boiler and tells it,

 "hey its only 10degs outside today we don't need to run at full pelt, lets crank the temp down to 50degs"

What this means in real world terms is your radiators will be cooler to the touch but because they are matched to outside temps you wont even notice and will be nice and comfy, giving you reduced gas bills,greater comfort and efficiency.

Also because your system will be running at lower temps for the majority of the year you will get less wear on mechanical parts such as pump and valves so the longevity of your system improves and your boiler will be running in "condensing" mode for longer.

"But what about these new smart stat thingamajigs?" Well yes they are a great product and have an important role to play especially with boilers  not compatible with WC and they compliment boilers with WC very nicley ,further increasing savings and efficiency.

"How much money will it save me?" The good news is these little gadgets are usually cheap at around £40-£50 and take no time to install, especially when done at the same time as a new boiler installation. Expect to save anywhere between 5 and 15% per year on your bills depending on what your current system is and insulation levels are.

So that's it WC explained, its kind of a industry secret but it shouldn't be, not many installers know about it or its benefits but those that do can offer their customers that little something extra to make there house more comfortable and efficient.

Here is a brochure from the boiler manufacturer Viessmann that explains  weather compensation really well.

By Dean Robinson