Protection for heating systems

Cosy warmth

Heating costs money. Just two millimetres of limescale on the heating rods in the boiler or heat exchanger can increase energy consumption by as much as 20%. With the correctly treated heating water from BWT, you can save on heating costs and ensure efficient, maintenance and trouble-free operation of the heating.
Frau genießt wohlige Wärme im Raum Frau genießt wohlige Wärme im Raum

Protection for heating systems

Solutions for your home

The key to the efficient and trouble free operation of a heating system is treating the water right.
BWT focuses on solutions to suit local, national and international heating systems!
Nachhaltiger Heizungsschutz Nachhaltiger Heizungsschutz

Protection for heating systems

Feel good.

Optimal heating water does not need any addi­tives although many local industry bodies and boiler manu­fac­tures make the addi­tion of chem­i­cals a stip­u­la­tion of good prac­tice and their warranty.

Naturally enough: when the weather outside is cold, we want to feel cosy inside. That's the whole point of central heating. What many people don't know, however is that the water with which the heating system is filled helps significantly in ensuring that everything runs smoothly. If the “wrong” water is used, or not treated appropriately deposits (such as limescale or slurry), corrosion or excess air in the system can lead to malfunctions, expensive repairs or even irreparable damage to the heating system. With the correctly treated heating water, you ensure efficient, maintenance and trouble-free operation. This saves heating costs and ensures cosy warmth.

Heating you can rely on

Protection for heating systems

Product Overview

Heating Protection

BWT offer the oppor­tu­nity to pre-​treat and protect the closed loop of your central heating system with the AQA therm HWG (heating water group) ensuring perfectly treated, stan­dard­ised heating water that can be used to fill or refill your heating system.

You can also protect your central heating boiler, water supply pipework and appli­ances with BWT Combi-​​Care, a compact polyphos­phate dosing system which offers protec­tion from limescale and corro­sion without tainting the water you live with.

AQA therm HWG AQA therm HWG

Protect your heating system and your warranty!

Filling your heating system with water treated in the right way is crucial for its efficiency, comfort and safety!


Save yourself some money! By choosing the right water solution for your home you can help lower heating costs and protect central heating systems including your boiler.
Schonen Sie Ihren Geldbeutel!


Enjoy permanent cosy warmth. The longer service life of your heating system also helps to maintain the value of your home.
Genießen Sie dauerhaft wohlige Wärme!


Where local condi­tions allow, BWT heating water without addi­tives is good for the envi­ron­ment, protects your heating from damage. If normal, untreated water is used in the closed loop of your central heating system, your guar­antee may be rendered void.
Schützen Sie Ihre Heizung!


We would be happy to help you find the BWT water softener that best suits your needs. Contact our BWT experts for advice.

Sometimes less is more

The same goes for heating water. BWT’s AQA therm HWG produces the perfect water for the protec­tion of your heating system. Reducing the precise ingre­di­ents like sodium and Calcium that other­wise cause deposits and corro­sion.

The envi­ron­ment bene­fits too as there is no need for envi­ron­men­tally harmful addi­tives! In addi­tion, the correct sodium content and venti­la­tion of the heating system result in the pH of the water adjusting natu­rally after just a few weeks.

BWT ReinHEIZgebot BWT ReinHEIZgebot

Why treat heating water?

Warum Heizungswasser aufbereiten?
Warum Heizungswasser aufbereiten?

Water plays a crucial role in heating systems: It trans­ports the heat produced in the boiler to around your home or offices. This water comes into contact with almost all the compo­nents of your heating system - including; pipework, radi­a­tors, expan­sion tanks, pumps and valves. For this reason, appro­pri­ately treating the water in heating circuit is a deci­sive step in ensuring smooth oper­a­tion.

Worry-​free with the right water

Heating systems have become more and more sophis­ti­cated in recent years, but this has also made them more suscep­tible to faults. Even minor irreg­u­lar­i­ties can lead to compli­ca­tions. Water and its constituent parts play an impor­tant role in this respect. Deci­sive are factors such as water hard­ness - i.e. mineral content - pH value and the concen­tra­tion of oxygen and salt.

Well-​known heating manu­fac­turers already require compli­ance with certain stan­dard values in their warranty condi­tions, e.g. in the UK this includes filling the central heating loop with hard or natu­rally occur­ring soft water and adding an appro­priate scale inhibitor. Conse­quently if untreated water is used for the heating, the guar­antee may be void in the event of damage. Prop­erly prepared heating water means you are always on the safe side. Get advice from an expert BWT Best Water Profes­sional in your area!

Limescale as a heat blocker

Limescale tends to accu­mu­late more and more at high temper­a­tures. Many of us are all familiar with this phenom­enon from the inside of our kettles, for example: When the water is heated, the limescale settles at the bottom of the kettle as a white deposit. The thicker this layer of lime, the longer the water takes to boil. This is exactly what happens in the heating system too. Layers of limescale have an insu­lating effect and make it harder to transfer heat, i.e. more energy has to be used in order for the heat output to remain constant. A limescale coating of only one millimetre increases energy consump­tion by up to 10 percent. Heating costs can soon start to soar.

Limescale parti­cles dissolved in the water can also be distrib­uted throughout the heating system and, among other things, cause valves to clog.

Kalk als Wärme-Bremse
Kalk als Wärme-Bremse

Avoiding corro­sion

Corro­sion is trig­gered by a variety of factors and usually goes unno­ticed. A mix of iron, steel, aluminium or copper, often found in modern heating systems, leads to elec­tro­chem­ical reac­tions and thus to corro­sion. The most familiar form of corro­sion is rust in iron. In addi­tion, the pH value of the water and the oxygen and salt content also play an impor­tant role. Acidic water with a pH value below 7 corrodes metallic parts. If the salinity - i.e. the elec­trical conduc­tivity - and the concen­tra­tion of oxygen are too high, corro­sion processes are accel­er­ated.

Metal parti­cles detached by corro­sion can get into the entire heating circuit and affect the whole system as so-​called corro­sion sludge. In the worst case scenarios this can reduce effi­ciency and lead to higher main­te­nance costs.

Air in the heating pipes

Although central heating is a self-​contained system, it is never completely airtight. For example, air can get into the system when replen­ishing water or due to leaky fittings and connec­tions. A partic­u­larly "leaky" point: the air-​perme­able plastic pipes used in under­floor heating.

Too much air in the system makes it diffi­cult to transmit heat and the radi­a­tors no longer get really warm. In addi­tion, noise caused by air - such as knocking or gurgling - can be quite annoying.

Luft in der Heizung
Luft in der Heizung

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