User’s manual
External cleaning of heat exchanger
In order to improve gas combustion and to achieve maximum heat exchange in the appliance, it is necessary to
keep finning of the heat exchanger 4 (p.
13.1
, page 24) in order. If heat exchanger is contaminated, it is necessary to
clean its surfaces where soot has appeared.
Before disassembling it is necessary:
1)
Switch the boiler off;
2)
Close CH inlet and output taps;
3)
Cover pump and other electrical (electronic) appliances with the foil against water entry;
4)
Drain the boiler.
To remove the soot it is necessary:
1)
To disassembly the heat exchanger (see p.
17.2
, page 37) and put it into soap solution or any other
synthetic detergent;
2)
Keep it in the soap solution for 10-15 minutes and clean the top and low surfaces by means of the soft
brush, then wash under strong current of water;
3)
Repeat above mentioned process again if necessary;
4)
Maintain heat exchanger with the new gaskets, rubber gaskets should be lubricated with the silicon oil;
5)
Check the joints of gas and water subject to disassembling on leakage (see p.16.2.1, page33).
16.1.2
Internal cleaning (washing) of heat exchanger
While applying heat exchange there is a chance of scale appearance on heat exchanger’s 4 (see p.
13.1
, page24)
inner surfaces.
To remove scale it is necessary:
1)
Demount the heat exchanger (see p.17.2, page37) and put it into a container;
2)
prepare 10% solution of citric acid (100 g of powdered citric acid for 1 liter of warm water);
3)
Fill this solution into heat exchanger’s tube;
4)
Keep this solution there for 10-15 minutes, then drain it and wash heat exchanger’s tube (coil)
thoroughly with water and if necessary to repeat all the procedure;
5)
Mount the heat exchanger with new gaskets;
6)
Check the joints of gas and water subject to disassembling on leakage (see p..16.2.1 , page 33).
Also it is necessary to clean DHW filter. It is located in the DHW flow sensor and can be demounted by means of
corkscrew or any other instrument.
16.2
Boiler’s operation check
At every boiler’s service it is necessary to check:
1)
Constant voltage regulator presence;
2)
Voltage and frequency of inlet current in the boiler in accordance with indicated technical requirements on the
data plate (see p.
2.2
, page5);
3)
Whether NG is supplied with the rated pressure 1,3-2,0 kPа (130-200 mm of water column) or LPG with the
rated pressure 2,9 kPa (300 mm of water column). To measure pressure is necessary while the boiler is on.
Before to check gas and water tract on leakage, or any other safety device, it is necessary to put a casing and
sealing cap off from the boiler (see p.17.1, page 36).
16.2.1
Checking gas and water systems leak resistance
Note! Checking leak-resistance of gas joints is performed by soup solution bubble test (or any other safe
methods without using open flame sources). Appearance of bubbles means gas leakage.
Check on leakage is performed in such joints as: gas supply regulator with gas supply pipe, gas pipe with burner
block and gas supply regulator, and also in the control points A and B of gas supply regulator (see p.
11
, page 22).
Checking water system on leakage is performed alternatively in CH and DHW modes. The following joins are
checked: boiler with the heating system and DHW, heat exchanger with the hydraulic group, tightness of hydraulic
group elements. Leakage in the joints is not allowed.
In case of gas or water leakage it is necessary to remove it by tightening the nuts (gauges) or installing a new
sealing.
16.2.2
Checking of safety device operation
16.2.2.1
Checking of water sensor in heating system
Before switching the boiler on, put the cables off from the water pressure sensor 25 (see p.
13.1
, page 24). During
the start up, boiler will display a symbol "04", signaling about the emergency in CH.
After eliminating the reasons of boiler’s emergent switching off (installing cables of the pressure sensor back),
boiler should automatically switch on.
