- Composition and order of preventive work
- Draining and replacing water, inspection of pipelines and fittings
- Boilers and automation
- Chemical flushing of the system: when is it needed and how to do it
- High pressure test
- Preparation and replacement of the coolant
Every summer, city heating networks carry out a whole range of measures for the repair and inspection of trunk networks. Autonomous hot water heating systems are no exception; on the contrary, they require even more attention. We will tell you about summer water heating service in this article..
The warm season is the most suitable period to drain the coolant from the heating system, diagnose the boiler room equipment and check the piping system. The detected faults are easier to eliminate at the time of downtime of the heating system than to deal with the cold in case of equipment failure in winter.
Composition and order of preventive work
To maintain the operability of water heating, there is a whole range of measures. Certain types of work are carried out at different intervals.
- Preventive inspection of gas boilers.
- Checking the functionality of automation.
- Boiler room alarm test.
- Checking / cleaning chimneys.
- Inspection of the heating pipeline.
Once every 3-5 years, the following can also be carried out:
- High pressure system test.
- Chemical flushing of the system.
- Replacing the coolant.
- Calibration of automation devices.
It is clear that the frequency of some work is a purely individual concept. For example, when using well and borehole water in heating, it is recommended to carry out an annual flushing without chemicals, and if a plunger pump is available, to test the system with increased pressure annually. More specific recommendations are given by the equipment manufacturers and the organization that installed the system..
Draining and replacing water, inspection of pipelines and fittings
To avoid corrosion of steel pipelines, they are kept constantly filled with water. This rule does not apply to systems with plastic pipes, however, if the boiler has a black iron heat exchanger, it is allowed to drain the water only with the valves on the direct and return pipes closed..
Water is drained to replace it or flush the system, repair pipelines and connections. Inspection of pipelines begins from the boiler and follows in a circle, starting with direct pipes. Leaks are often local and intermittent; most of them are not detected during the heating season. However, leaks can be detected by characteristic traces: white or rusty bloom, stains from small pools of water, a change in the color of the sealant. Even with slight traces of leakage, repack the squeegee or joint, or seal the radiator sections.
Replacement of water in the heating system is carried out at the final stage of prevention, it is recommended to do this before the start of each new heating season no later than 30–40 days before it starts. Water from the system is drained and the formed deposits are flushed out of the pipes, supplying pressure to the upper point of the circuit through the direct supply pipe. The flushing liquid is drained until it is clarified, then the system is filled with water through the lower supply pipe under low pressure.
Boilers and automation
Maintenance of electric boilers includes inspection of heating elements, revision of starting equipment and hauling of electrical connections. The heating elements are removed from the flask, loose scale deposits are removed and the plaque crust removed with a cleaning agent. The starters should be disassembled and the silver-plated contacts should be brought to a shine with a sandpaper-zero. All connections of cables and wires must be released by 2/3 clamps and tightened again.
Comprehensive boiler maintenance can only be performed by a specialized organization, but a lot depends on the owner. First of all, you must definitely do:
- visual inspection with the cover removed;
- treatment of gas pipeline connections with soapy water;
- check of draft and air supply;
- visual assessment of the condition of the burner;
- checking the piezo ignition.
In boilers removed from the warranty, it is allowed to independently clean the flame sensor, air sensor and boiler flue ducts. In this case, the connections of the gas pipes must remain intact, and it is also not allowed to clean the burner yourself..
With complex maintenance, the specialist will perform all the listed actions, as well as adjust the fuel supply, set up and test the automation, analyze the composition of the exhaust gases.
Maintenance of solid fuel boilers includes, first of all, a comprehensive cleaning of the furnace, pyrolysis chamber and chimney ducts. Cleaning is carried out with a metal brush, removing carbon deposits and scale from the metal, but not cleaning the surface to a shine. This does not apply to heat exchangers: their surface must be as clean as possible.
Chemical flushing of the system: when is it needed and how to do it
The regularity of the chemical wash depends on the quality of the water used. Many do not flush the system at all; in the case of a special coolant, this is normal practice. But the use of water is associated with the formation of scale and other deposits, which reduce the efficiency of heat transfer and significantly increase fuel consumption..
The system is flushed with a special pumping unit, which can be rented for a while. The system is flushed with a special solution of cleaning chemicals, which are selected according to the type of pipes, radiators and the material of the heat exchanger in the boiler. In special cases, the boiler is washed separately.
When flushing, it is important to close the taps of all auxiliary equipment: expansion tank, pumps, bleed valves, etc. At one point, the pipe ring should be closed, and on both sides of the valve there are nozzles for connecting flushing hoses.
Flushing is carried out in two stages: first, the system is pumped with a chemical solution for 40-60 minutes, then the chemistry is washed out with clean water several times.
High pressure test
Quite often, after flushing, small leaks open at the pipe connections. To make sure they are absent, the system is tested with high pressure. Usually it is 0.4-0.6 MPa. A plunger pump is used to pump an incompressible fluid in the system..
The test pressure is held for at least 20 minutes, during this time the joints and welds are inspected, the hidden pipelines are checked by ear. If during the test the pressure does not drop by more than 0.01 MPa, the system meets the tightness standards.
Hydraulic tests are carried out immediately after flushing with additional equipment disconnected from the system..
Preparation and replacement of the coolant
In most autonomous heating systems, tap water acts as a coolant and this is not entirely correct. Untreated water contains a large amount of salts and oxygen, which causes scale deposits and metal corrosion.
The best option for heating systems is collected rainwater. It is possible to use water after treatment with reverse osmosis or boiling. You can also find special inhibitors on sale that block the effects of salts and oxygen, but such agents are very specific for use with certain materials of pipes, seals and radiators. In general, a good solution would be to install the simplest filter system on the heating feed..