Strebel S-FX 125, Installation Operating & Maintenance Manual, Page: 51 / 68

51
14 ADJUSTING AND SETTING THE BOILER
Before carrying out any adjusting of the burner, carefully read this complete chapter.
The initial lighting of the appliance must be performed by a licensed Gas Technician.
Failure to follow these instructions may result in property damage, serious injury or death.
As soon as the appliance has been fully installed (with regard to hydraulics, filling and de-
aeration of installation, gas, flue gas, air intake, wiring etc.) according to the preliminary
installation instructions, the boiler may then be wired to an electrically grounded power supply
source. The boiler should always be connected to a disconnect or external power shutoff.
The boiler must be electrically bonded to the ground in accordance with the requirements of
the local authority having jurisdiction.
14.1 Introduction
The boiler must always be adjusted in the next situations:
- A new boiler is installed
- As part of a service/maintenance check, in case the CO
2
values turns out to be incorrect .
- The gas valve has been replaced .
- Gas conversion from natural gas to LPG or LPG to natural gas.
- The venturi has been replaced.
- The fan has been replaced
- The flue gas check valve has been replaced
In any of the cases described, always check the gas/air ratio of the combustion figure (CO
2
) at maximum and
minimum input.
First set the boiler at maximum load and subsequently at minimum load and repeat if necessary (adjustments at
maximum load influence values at minimum load and vice versa).
14.1.1 C
OMBUSTION TABLE
Table 1: CO
2
values for maximum and minimum load on natural gas.
.
Table 2: CO
2
values for maximum and minimum load on LPG.
Gas Type
CO
2
[%]
Natural Gas (G20)
Boiler Model max load min load
S-FX 70 9.2 - 9.4 8.7 - 8.9
S-FX 125 9.2 - 9.4 8.6 - 8.8
S-FX 220 9.2 - 9.4 8.6 - 8.8
S-FX 320 8.9 - 9.1 8.4 - 8.6
Gas Type CO
2
[%]
LPG (G31)
Boiler Model max load min load
S-FX 70 10.2 - 10.4 9.7 - 9.9
S-FX 125 10.4 - 10.6 9.6 - 9.8
S-FX 220 10.4 - 10.6 9.6 - 9.8
S-FX 320 10.4 - 10.6 9.6 - 9.8
WARNING