How to Solve the Most Common Heating System Problems

A well-maintained, properly adjusted, and clean heating system ensures economical and trouble-free operation. However, if maintenance is neglected, radiators may heat less, unevenly, or become noisy. Heating costs can then significantly increase without you knowing, as the heating elements are paradoxically cold. Thermal comfort decreases, but the risk of serious malfunction or breakdown increases. Therefore, problems need to be addressed promptly.

Here are the five most common heating system problems and their solutions.

Air-locked Radiators

Air-locking is the most common problem in heating systems. Although the solution is very simple, many people underestimate or do not perform bleeding at all. How does air get into the operating fluid and what can it cause?

Oxygen is a natural component of water, so it cannot be completely removed from the operating fluid. In this natural amount, it is not dangerous to the health of the heating system. The problem is the air that enters the heating when filling the system or through various joints and pumps. This air is undesirable and causes:

corrosion of metal parts of the heating system,
reduced heating efficiency,
uneven heating,
cavitation noise.

Bleeding the heating system is done either manually using bleed valves, or automatically thanks to air separators, which are permanently installed, so you don't have to think about bleeding at all.

Unbled radiators heat less, but cost more.

Corrosion

Corrosion significantly shortens the lifespan of the heating system and increases the risk of cracks, leaks, and breakdowns.

The most common is so-called oxygen corrosion, caused by air in the heating system. The solution is therefore regular bleeding of the system. Galvanic corrosion is caused by the presence of different materials with varying electropositivity. The entire system (radiators, pipes, joints, boiler) should therefore be designed using one material.

Microbial corrosion results from the metabolism of microorganisms in the operating fluid. This problem mainly affects heating systems with untreated water from private sources. Well or borehole water must always undergo proper treatment before being introduced into the system.

Low Quality of Operating Fluid

In addition to the quality of the heating system, it is necessary to focus on the quality of the operating fluid – specifically its composition and possible types of contamination. Contamination in the operating fluid can generally be divided into magnetic and non-magnetic.

Non-magnetic impurities mainly include limescale. Limescale is a thermal insulator, and its deposits reduce heating efficiency and restrict water flow. Water hardness can be chemically adjusted, but only after expert consultation, as softening also affects the water's pH, which can lead to corrosion.

Magnetic impurities (particles of magnetite, metal shavings, etc.) are naturally released into the operating fluid from the heating system. They can be very effectively removed from the water using a magnetic filter.

We must not forget the possible microbial contamination of the operating fluid. Bacteria in the water create a biofilm, which, like limescale, reduces heat transfer efficiency and clogs individual components of the heating system.

Seizing of the Pump and Other Components

If water contamination in the heating system is not addressed, it can lead to seizing of the circulation pump, or possibly clogging of control valves or heat exchangers in boilers.

Modern low-energy pumps are particularly susceptible to this type of malfunction, as they contain a magnet. This improves the pump's operation and reduces energy costs, but also attracts magnetic impurities present in the water. If seizing occurs, the pump usually needs to be replaced.

Flamco dirt separator with magnet.

Leaking Operating Fluid

Especially after filling the heating system, it is necessary to check for any water leaks. However, checks should be carried out continuously throughout the heating season. Leaky joints not only cause damp spots and mould, but also allow air to enter the heating system. As mentioned above, air leads to reduced heating efficiency and corrosion.

If the sealing problem is not resolved immediately, it will worsen and could end in a breakdown. Therefore, if a leak is detected, call a heating technician immediately, never attempt to repair leaky joints yourself. An unprofessional intervention could irreversibly damage the heating system.

Five Steps to a Perfectly Maintained Heating System

Maintaining a heating system is not complicated if you follow 5 basic rules:

Do not underestimate the heating project. The heating technician should choose suitable construction materials and dimensions for the system and ensure the quality of joints and seals during installation.
Always use magnetic filters for heating, which continuously clean the operating fluid of solid impurities. Clean the magnetic filter once a year.
Before the heating season starts, bleed the radiators, adjust the system, and check the function and sealing after filling.
Throughout the heating season, monitor the temperature of the radiators, the pressure in the heating system, and the sealing of joints.
Never interfere with the heating system on your own. In case of problems, contact a heating technician.