How to drain water from the boiler

Most heating systems work by transferring thermal energy using a coolant. Maintenance of the entire heating complex, as well as individual elements, requires draining the liquid. The need to repair or replace the boiler is impossible without freeing the internal cavity from water.

Preparation

To drain liquid from heating gas equipment, it is necessary to prepare a hose, the inner diameter of which must correspond to the outer size of the drain valve located below the boiler level. Such a valve is installed on the heating “return”, at the lowest point. In addition to the hose, prepare a container that has the same volume as the expected amount of water to be drained.

Preparatory work also includes checking the shut-off valves of attached equipment, including taps, on the “supply” and “return” of the boiler.

IMPORTANT! Checking the shut-off valves is carried out only when the heating unit is turned off! Closing the valve on the main pipeline during operation will lead to equipment failure!

After checking, the hose is connected to the drain fitting, directed into a container and the unit is turned off.

Types of boilers

Various types of equipment are used to heat residential premises. Based on the type of fuel they operate on, they are divided into:

• solid fuel;
• electrical;
• liquid fuel equipment;
• gas;
• combined units.

The specifics of solid fuel make it possible to divide the equipment into several more subtypes.

REFERENCE! Combined units are made using two heating sources, often combining electric with another type.

By purpose:

• single-circuit, only for heating systems;
• double-circuit, for heating and hot water preparation.

Most heating equipment designs have internal cavities in which the coolant is heated to a set temperature. When draining water from the boiler, the internal part is freed from liquid and makes it possible to service all components and connections of the unit.

Methods for draining water

Having completed the preparatory work, open all the radiator taps, then unscrew the coolant flow control valves (if any). After this, the drain bypass is opened and the liquid is directed into a specially prepared container. First, the pressure on the pressure gauge will drop, and then, accompanied by a quiet hiss, the stream will fill the container.

A sound similar to a soft whistle will be produced by the automatic air vent that is equipped with the heating system. The presence of sound indicates the serviceability of the device, which bleeds excess air during operation of the unit. The method considered freed not only the boiler from water, but also all heating appliances and pipes. For better emptying of devices, use Mayevsky taps, opening each of them in turn.

ATTENTION! When the hot water heating heat exchanger of a double-circuit boiler is empty, after switching off, first open the hot water supply tap until the liquid cools.Then turn off the cold water supply and, if necessary, empty the heat exchanger of its contents, unscrew the hot water supply fitting.

Modern boilers, especially gas boilers, are equipped with an automatic air vent and drain fitting. To drain liquid from such a unit, it is enough to open the drain valve after carrying out the preparatory work. If the equipment is installed at the top point of the heating system, liquid will flow out, freeing only the boiler cavity. And through the unit installed below the heating radiators, water from the upper appliances will drain.

IMPORTANT! In order not to drain liquid from all circuits of the heating system, boiler shut-off valves are used, which connect the equipment to the “supply” and “return” pipes.

In what situations is water drained?

Carrying out work to drain liquid from the boiler is carried out:

• when replacing heating equipment;
• when a unit malfunction is detected and individual components are repaired;
• if it is necessary to eliminate leaks at the connections of taps, fittings or other pipes of the unit;
• when the heating is turned off, in winter, for a long period;
• when replacing coolant.

Carrying out repair and maintenance work on the heating system requires draining the liquid. Emptying the equipment from the coolant can be done by anyone with little technical skills. The ability to drain water from the boiler will allow you to easily cope with any equipment malfunction, which is especially important in winter.