A heating system is a closed circuit in which the heat transfer medium carries heat from the source (boiler house, district heating network, heat substation) to heating appliances: radiators, convectors, pipe registers, air heaters. Over time, deposits build up in the pipes and appliances, and the system no longer delivers its design heat output.
Deposits and why they are dangerous
Most deposits are steel corrosion products (iron oxides, sludge) formed when oxygen-containing water comes into contact with the metal of pipes and appliances. When the system is topped up with untreated water, scale (hardness salts) forms on the walls of heating appliances. Some elements of the heating circuit may be subject to biofouling. Sand, mill scale and welding spatter enter the system with make-up water and after repairs. Deposits settle where the medium flows slowly — in the lower part of radiators, at bends, in dirt separators, filters and valves.
In practice this leads to:
- lower heat output of heating appliances and underheated rooms;
- an unbalanced system: distant risers and branches heat up worse;
- higher hydraulic resistance and higher load on circulation pumps;
- failures of shut-off and control valves and thermostatic valves;
- accelerated pipe corrosion, up to leaks.
Heating systems are usually flushed every year after the end of the heating season, as well as after repairs. Flushing quality is assessed by how clear the discharged water becomes.
Cleaning methods
- Chemical flushing — dissolving deposits with chemicals circulated through the internal cavities of the equipment, followed by neutralisation and passivation of the metal; used where tools cannot reach.
- Hydrodynamic cleaning — breaking up deposits with a high-pressure water jet using high-pressure units, channel-cleaning hoses and special nozzles; for tubes, channels and vessels accessible to the nozzle.
- Mechanical cleaning — removal of dense and fully blocking deposits with manual and power tools; as a rule, requires disassembly or opening of the equipment.
- Dry ice blasting (cryoblasting) — gentle cleaning of accessible surfaces with solid carbon dioxide pellets, without chemicals, water or abrasives.
- Laser cleaning — non-contact removal of rust, mill scale, carbon deposits and coatings from accessible metal surfaces.
The applicability of a method to specific equipment is determined after inspection and agreed with the customer; methods are often combined. The methods used for each type of equipment are listed in its description on this page.
How the work is carried out
- Inspection. Examination of the equipment and, if necessary, video inspection (endoscopy) of internal surfaces. We determine the composition and thickness of deposits.
- Method selection. The method and mode are agreed with the customer for the specific equipment, material and deposits.
- Preparation. Any assembly and disassembly work required by the selected cleaning method.
- Cleaning. Cleaning by the selected method with control of the result.
- Protection. After chemical flushing — neutralisation of chemical residues, water rinsing and passivation of the metal surface against corrosion.
We work on a one-off basis or under a scheduled maintenance contract, with periodic inspections and preventive cleaning.
What we need for a quote
- building type and system type (single-pipe, two-pipe), number of storeys;
- pipe material and type of heating appliances;
- system volume or heated area — if known;
- signs of malfunction: cold sections, noise, frequent blockages;
- photos and videos, equipment passport or diagram — if available;
- preferred timing: between heating seasons, urgent work.
Frequently asked questions
How often should a heating system be flushed?
It depends on the quality of the heat transfer medium and the condition of the system. Signs include uneven heating of radiators, noise and lower room temperatures with the same network parameters.
Which method suits our system?
For the whole system, usually chemical flushing along the circuit; for individual clogged sections, hydrodynamic cleaning. We select the method after inspection.
Can the system be flushed during the heating season?
This is discussed for each site: it depends on the system layout and whether individual circuits can be shut off. Please state this in your request.