E25 / E29
10
EN
cod. 3541M540 - Rev. 01 - 06/2017
4.4 Routine servicing, maintenance & repair
General
PLEASE NOTE:
During routine servicing, and after any maintenance or change of part
of the combustion circuit, we recommend that the following is checked:
•
The integrity of the flue system and the flue seals;
•
The integrity of the boiler combustion circuit and the relevant seals;
•
The operational (working) gas inlet pressure at maximum rate, as described in
section 4.4;
•
The gas rate, as described in section 4.4;
•
The combustion performance, as described in section 3.4 Combustion check.
Competence to carry out the check of combustion performance
PLEASE NOTE:
BS 6798: 2009
Specification for installation and maintenance of
gas-fired boilers of rated input not exceeding 70 kW net
advises that:
•
The person carrying out a combustion measurement should have been assessed
as competent in the use of a flue gas analyser and the interpretation of the results;
•
The flue gas analyser used should be one meeting the requirements of BS7927 or
BS-EN50379-3 and be calibrated in accordance with the analyser manufacturers’
requirements, and
•
Competence can be demonstrated by satisfactory completion of the CPA1 ACS as-
sessment, which covers the use of electronic portable combustion gas analysers in
accordance with BS 7967, Parts 1 to 4.
Periodical check
To keep the unit working properly over time, it is necessary to have qualified personnel
make an annual check that includes the following tests:
•
The control and safety devices (gas valve, flow meter, thermostats, etc.) must func-
tion correctly.
•
The flue pipe must be fully efficient.
•
The airtight chamber must be sealed
•
The air-flue terminal and ducts must be free of obstructions and leaks
•
The condensate evacuation system must be efficient with no leakage or obstructions.
•
The burner and exchanger must be clean and free of scale. When cleaning, do not
use chemical products or wire brushes.
•
The electrode must be free of scale and properly positioned.
•
The gas and water systems must be leak free.
•
The water pressure in the heathing system must be about 1 bar; otherwise, bring it
to that value.
•
The circulation pump must not be blocked.
•
The expansion tank must be filled.
•
The gas flow and pressure must correspond to that given in the respective tables.
•
The electrode must be properly positioned and free of deposits.
fig. 25 - Electrode positioning
A
The boiler casing, panel and aesthetic parts can be cleaned with a soft damp
cloth, possibly soaked in soapy water. Do not use any abrasive detergents and
solvents.
Combustion check
Connect the flue gas analyzer to the flue gas sampling point as shown in the fig. 26 and
check combustion as described in table 7 and table 8.
1.
Press the CH button for 5 seconds to place boiler into test mode
2.
Wait for 10 minutes for the boiler to stabilize fully
3.
Take the measurement and record
4.
Take the boiler to minimum output by pressing the CH – button, allow the boiler to
stabilize for a further 10 minutes.
5.
Take the measurement and record.
fig. 26 - Flue gas sampling point
1
= Air -
2
= Flue gas
Tabella. 7 - Maximum rate
Tabella. 8 - Minimum rate
If the combustion reading is greater than the acceptable value AND the integrity of
the complete flue system and combustion circuit seals have been verified and the
inlet gas pressure (and gas rate) have been verified, proceed as in section Setting
the Air/Gas Ratio valve
.
3
±
0,5
=
=
ACCEPTABLE
COMBUSTION RANGE
MAXIMUM RATE AFTER 10 MINUTES FROM COLD
Boiler Model
CO/CO
2
RATIO
CO
2
NG
CO
2
LPG
E25
0.004
7,2 ÷ 7,9
8,2 ÷ 8,9
E29
0.004
ACCEPTABLE
COMBUSTION RANGE
MINIMUM RATE AFTER 10 MINUTES FROM COLD
Boiler Model
CO/CO
2
RATIO
CO
2
NG
CO
2
LPG
E25
0.004
5,7 ÷ 6,2
6,1 ÷ 6,6
E29
0.004
1
2
1
2