Service mode › Alpha
Alpha boiler service mode
How to put an Alpha boiler into service mode, so it holds maximum or minimum rate while you take combustion readings. 35 models from 18 Alpha installation and servicing manuals, each step with the page it came from.
Grouped by manual: one manual usually covers a range of outputs. The CO₂ figures are the manual's own. Set and check them with a calibrated analyser, never by eye.
Alpha C23/27 Range of Wall Mounted, Fan Assisted, Room Sealed, Gas Fired Combination Boilers
Covers: C27
GC 47-532-22, 47-532-23
Service Gas Pressure Check
- Turn the boiler off.
- Loosen the burner pressure test point screw on the gas valve.
- Connect a pressure gauge.
- Set selector switch to (DHW only) and fully open a hot water tap.
- Allow to run for 10 minutes to check pressures.
- After checks, disconnect gauge and tighten test point screw.
From manual 1.019966, page 16.
The burner pressure settings have been factory set and do not require adjusting. If incorrect, check that the inlet gas pressure is 20 mbar. (page 16)
Alpha CB50
Covers: CB50
GC 47-532-18
Entering Service/Test Mode
- Set the selector switch to 0.
- Loosen the burner pressure test point screw on the gas valve and connect a pressure gauge.
- To test Hot Water mode: Set selector to DHW icon and DHW thermostat to max.
- To test Central Heating mode: Set selector to DHW+CH icon and CH thermostat to max.
From manual 1.017833, page 18.
Exiting Service Mode
- Set the selector switch to 0 to turn off the boiler.
- Disconnect the pressure gauge and tighten the test point screw.
- Test for gas soundness using suitable leak detection fluid.
From manual 1.017833, page 20.
The burner pressure settings have been factory set and do not require adjusting. If incorrect, check that the inlet gas pressure is 20 mbar. (page 18)
Alpha CD50S and 70S
Covers: Cd50s Cd70s
Entering Installer Parameters
- Press the MODE and STEP keys at the same time for 2 seconds; the display will show the wording CODE.
- Change the value by operating the + or - keys until reaching the correct code.
- Press the STORE key to confirm.
From manual 1.027175, page 21.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| LPG | 10.6% ± 0.2% | 10.1% ± 0.2% | 250 ppm |
CO₂ and CO from manual 1.027175, page 4. Check against the data badge.
Warning: Before servicing the boiler, isolate the electrical supply and close the boiler gas service cock. The factory-set valve/adjustment is at P1 and Off-set adjustment screw (Fig. 23) (page 19)
Alpha E-Tec 28 and 33 Wall Mounted, Fan Assisted, Room Sealed, Gas Fired, High Efficiency Condensing Combination Boiler
Covers: E-Tec 33
GC 47-532-70
Chimney Sweep Mode (Service / Test Mode)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80 - 90% (Max CH output), 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.042188 rev. ST.003781.001, page 29.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| LPG | 11.2% (+0.2 / -0.4) | 10.0% (+0.4 / -0.2) | – |
CO₂ and CO from manual 1.042188 rev. ST.003781.001, page 5. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 29)
Alpha E-Tec Plus 28, 33 and 38
Covers: E-Tec Plus 28, E-Tec Plus 33, E-Tec Plus 38
GC 47-532-77, 47-532-78, 47-532-79
Chimney Sweep Mode (Force Max / Min Rate)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80-90% (Max CH output), and 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual Part No. 1.043044 rev. ST.004614/001, page 31.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| LPG | 11.4% (+0.1 / -0.3) | 10.6% (+0.3 / -0.1) | – |
CO₂ and CO from manual Part No. 1.043044 rev. ST.004614/001, page 6. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 31)
Alpha E-Tec Plus 28NX, 33NX and 38NX
Covers: E-Tec Plus 28NX, E-Tec Plus 33NX, E-Tec Plus 38NX
GC 47-532-89, 47-532-90, 47-532-91
Chimney Sweep Mode (Combustion Check)
- Without any CH or DHW demand, press and hold the reset button for five seconds and the boiler will fire at a fixed output.
- Sc will be shown on the display (DHW digits) to indicate this mode.
- Once activated, select whether to make the check in CH status or DHW status by opening any hot water tap.
- If active in CH mode, the CH +/- buttons can be used to select the power from minimum power (0%) to maximum CH power (99%) in 1% intervals.
- If active in DHW mode the CH +/- buttons can be used to select the power from minimum power (0%) to maximum DHW power (99%) in 1% intervals.
- This mode will remain active for fifteen minutes or can be cancelled by pressing the RESET button.
From manual 1.048200, page 36.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| LPG | 10.2% (-10.4) | 9.7% (-9.9) | – |
CO₂ and CO from manual 1.048200, page 7. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. (page 36)
Alpha Evoke 28 and 33
Covers: Evoke
GC 37-532-76, 47-532-71, 47-532-72, 47-532-75
Entering Chimney Sweep Mode
- Ensure no CH or DHW demand.
- Press and hold the reset button for eight seconds.
- Boiler will fire at a fixed output (display flashes parasol and snowman).
- Use DHW up/down buttons to toggle between 0%, 80-90% (Max CH), and 99% (Max DHW) outputs.
From manual 1.042372 rev. ST.003782.000, page 29.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.7% (+0.5 / -0.2) | 8.8% (+0.2 / -0.3) | 450 ppm |
| LPG | 11.4% (+0.1 / -0.3) | 10.6% (+0.3 / -0.1) | – |
CO₂ and CO from manual 1.042372 rev. ST.003782.000, page 5. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 29)
Alpha Evoke 28NX and 33NX
Covers: Evoke 28NX, Evoke 33NX
GC 47-532-84, 47-532-85, 47-532-86, 47-532-87
Chimney Sweep Mode (Combustion Testing)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80 - 90% (Max CH output), and 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.046746, page 30.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.2% ± 0.3 | 8.5% ± 0.2 | 250 ppm |
| LPG | 10.2% ± 0.2 | 9.7% ± 0.2 | 250 ppm |
CO₂ and CO from manual 1.046746, page 5. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 30)
Alpha InTec 12S, 18S, 28S Range of Wall Mounted, Fan Assisted, Room Sealed, Gas Fired, High Efficiency Condensing System Boilers
Covers: Intec 12S, Intec 18S, Intec 28S
GC 41-532-22, 41-532-23, 41-532-24, 41-532-25, 41-532-26, 41-532-27
Force Maximum Rate (Burner Pressure & Combustion Check)
- Press and hold in the reset button for eight seconds and the boiler will fire at a fixed output depending on the position of the boiler central heating thermostat knob.
- Turn the boiler central heating thermostat to maximum to check the maximum central heating burner pressure.
- With the boiler central heating thermostat set to maximum fully open a hot tap to check the maximum domestic hot water burner pressure.
From manual 1.030769, page 26.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| Intec 12S | Natural gas | 9.4% ± 0.25% | 8.9% | 200 ppm |
| Intec 12S | LPG | 10.8% ± 0.5% | 10.4% | – |
| Intec 18S | Natural gas | 9.4% ± 0.25% | 8.6% ± 0.25% | 200 ppm |
| Intec 18S | LPG | 10.5% ± 0.5% | 9.7% ± 0.5% | – |
| Intec 28S | Natural gas | 9.5% ± 0.25% | 8.7% ± 0.25% | 200 ppm |
| Intec 28S | LPG | 10.5% ± 0.5% | 9.7% ± 0.5% | – |
CO₂ and CO from manual 1.030769, page 4, 5. Check against the data badge.
Note: The burner pressure settings have been factory set and should not require adjusting. (page 26)
Alpha InTec 30GS and 40GS
Covers: Intec 30GS, Intec 40GS
GC 47-532-50, 47-532-51, 47-532-57, 47-532-58
Force fixed output / test burner pressures and combustion
- Press and hold in the reset button for eight seconds and the boiler will fire at a fixed output depending on the position of the boiler central heating thermostat knob.
- Turn the boiler central heating thermostat to maximum to check the maximum central heating burner pressure.
- With the boiler central heating thermostat set to maximum fully open a hot tap to check the maximum domestic hot water burner pressure.
From manual 1.038435 ST.001940/000, page 27.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| Intec 30GS | Natural gas | 9.4% ± 0.25% | 8.6% | 200 ppm |
| Intec 30GS | LPG | 10.5% ± 0.5% | 9.7% | – |
| Intec 40GS | Natural gas | 9.5% | 8.7% | 200 ppm |
| Intec 40GS | LPG | 10.5% | 9.4% | – |
CO₂ and CO from manual 1.038435 ST.001940/000, page 4, 5. Check against the data badge.
The burner pressure settings have been factory set and should not require adjusting. (page 27)
Alpha InTec² 20SE and 30SE
Covers: Intec² 20SE, Intec² 30SE
GC 41-532-28, 41-532-29
Enter Chimney Sweep Mode (Combustion Check)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- The boiler output can then be manually controlled by turning the Central Heating control knob from the minimum CH output to the maximum CH output (display shows percentage from 00 minimum to 99 maximum).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.035664, page 28.
Enter CO2 Calibration Setup Menu
- Turn the DHW selector to 6 o'clock and the CH selector to 9 o'clock.
- Press the 'RESET' button for eight seconds until the parasol and snowman flash at the same time (chimney sweep mode).
- Press the 'Summer/Winter' button within three seconds to enter the setup menu.
From manual 1.035664, page 30.
Enter Fast Calibration Mode
- Turn the DHW selector to 6 o'clock and the CH selector to 9 o'clock.
- Press the 'RESET' button for eight seconds until the parasol and snowman flash at the same time (chimney sweep mode).
- Press the 'INFO' button within three seconds.
From manual 1.035664, page 31.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.2% ± 0.8% | 9.0% ± 0.8% | 200 ppm |
| LPG | 10.7% ± 1% | 10.0% ± 1% | – |
CO₂ and CO from manual 1.035664, page 4. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. (page )
Alpha InTec² 25XE and 28XE
Covers: Intec2 25 28XE
Enter Service / Chimney Sweep Mode
- Without any CH or DHW demand, press and hold the reset button for eight seconds.
- The parasol and (parasol/snowman) symbols will flash.
- Boiler output can be manually controlled by turning the Central Heating control knob (00 min to 99 max).
- Mode remains active for 15 minutes or cancel by turning the boiler off.
From manual 1.038088, page 28.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.1% | 9.0% | 200 ppm |
| LPG | 10.8% ± 1% | 10.0% ± 1% | – |
CO₂ and CO from manual 1.038088, page 4. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. (page 28)
Alpha Pro Tec Plus 50, 70, 90 and 115
Covers: Pro Tec 24, Pro Tec Plus
Chimney Sweep Function (Service Mode)
- Press and hold button 'A' to activate.
- Select minimum output (0%) by pressing the DHW - button.
- Select maximum output (100%) by pressing the DHW + button.
- Output values between 0% and 100% can be selected using the CH + and - buttons to change the value in 1% increments.
- This function can be disabled by pressing and holding in button 'A'.
From manual 1.038054, page 27.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.5% | 9.1% | 14 ppm |
| LPG | 10.6% | 10.1% | 184 ppm |
CO₂ and CO from manual 1.038054, page 5. Check against the data badge.
E-Tec 20NXS, 30NXS and 35NXS
Covers: E-Tec 20NXS, E-Tec 30NXS, E-Tec 35NXS
GC 41-532-53, 41-532-54, 41-532-55
Chimney Sweep Mode (Checking combustion)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80 - 90% (Max CH output), 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.046747, page 31.
Programming the PCB (Service/Parameter Menu)
- Press and hold the RESET and INFO buttons at the same time for 5 seconds until the display shows two flashing dashes (- -).
- Enter the password '69' using the DHW up/down buttons (first digit) and CH up/down buttons (second digit).
- Press the operating mode button to confirm the password and access the menu.
- Scroll through the four submenus (P, t, A, S) by pressing the DHW up and down buttons, and press the mode button to access the menu.
- Scroll through the parameters (P0-P5, t0-t9, A0-A6, S0-S2) using the DHW up and down buttons, then press the mode button to display the parameter.
- Press the mode button to display the parameter and adjust its value using the CH up and down buttons.
- Press the mode button for more than 1 second to store the parameter value (confirmation is given by '88' for 2 seconds).
From manual 1.046747, page 35.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| E-Tec 20NXS | Natural gas | 9.5% ± 0.4 | 9.1% ± 0.1 | 250 ppm |
| E-Tec 20NXS | LPG | 10.4% ± 0.2 | 10.0% ± 0.2 | 250 ppm |
| E-Tec 30NXS, E-Tec 35NXS | Natural gas | 9.2% ± 9.1 to 9.5 | 8.5% ± 8.3 to 8.7 | 250 ppm |
| E-Tec 30NXS, E-Tec 35NXS | LPG | 10.2% ± 10.0 to 10.4 | 9.7% ± 9.5 to 9.9 | 250 ppm |
CO₂ and CO from manual 1.046747, page 6. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 31)
E-Tec 20S, 30S and 35S
Covers: E-Tec 20S, E-Tec 35S
GC 41-532-47, 41-532-52
Chimney Sweep Mode (Combustion Check Mode)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80 - 90% (Max CH output), and 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.047103 rev. ST.006282/006, page 31.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| E-Tec 20S | LPG | 11.4% (+0.1 / -0.3) | 10.6% (+0.3 / -0.1) | – |
| E-Tec 35S | LPG | 10.9% (+0.4 / -0.2) | 9.9% (+0.4 / -0.2) | – |
CO₂ and CO from manual 1.047103 rev. ST.006282/006, page 6. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. (page )
E-Tec 28NX and 33NX
Covers: E-Tec 28NX, E-Tec 33NX
GC 47-532-80, 47-532-81, 47-532-82, 47-532-83
Chimney Sweep Mode (Combustion Checking)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Using the DHW up and down buttons you can change between three predefined output levels: 0% (low fire), 80 - 90% (Max CH output), and 99% (Max DHW output).
- This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.046745, page 30.
Programming the PCB (Service/Parameter Mode)
- Press and hold the RESET and INFO buttons at the same time for 5 seconds; the display will show two flashing dashes (- -).
- Enter the password '69': use the DHW up/down buttons to enter the first digit and the CH up/down buttons to enter the second digit.
- Press the operating mode button to confirm the password and access the menu.
- Scroll through the submenus (P, t, A, S) using the DHW up and down buttons, then press the mode button to access the menu.
- Press the mode button to display the parameter, then adjust its value using the CH up and down buttons.
- Press the mode button for more than 1 second to store the parameter value (confirmation given by the numbers 88 appearing for 2 seconds).
- Press the RESET button to exit a parameter without changing its value, or press RESET to exit the programming mode.
From manual 1.046745, page 33.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| E-Tec 28NX | Natural gas | 9.2% (-9.5) | 8.5% (-8.7) | 250 ppm |
| E-Tec 28NX | LPG | 10.2% (-10.4) | 9.7% (-9.9) | 250 ppm |
| E-Tec 33NX | Natural gas | 9.2% ± 0.2 | 8.5% ± 0.2 | 250 ppm |
| E-Tec 33NX | LPG | 10.3% ± 0.2 | 9.6% ± 0.2 | 250 ppm |
CO₂ and CO from manual 1.046745, page 5. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 30)
Eco
Covers: Eco, Eco 11 13
GC 47-532-59
Entering Service Mode
- Press and hold the reset button for eight seconds.
- The boiler will fire at a fixed output depending on the position of the boiler central heating thermostat knob.
- Turn the boiler central heating thermostat to maximum to check the maximum central heating burner pressure.
- With the boiler central heating thermostat set to maximum, fully open a hot tap to check the maximum domestic hot water burner pressure.
From manual 1.033694, page 22.
| Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|
| Natural gas | 9.55% | 8.9% | 200 ppm |
CO₂ and CO from manual 1.033694, page 4. Check against the data badge.
The burner pressure settings have been factory set and should not require adjusting. Replacement of a gas valve or PCB must be carried out by a Gas Safe registered engineer with the use of a flue analyser. (page 22)
InTec² 26CE, 30CE and 35CE
Covers: Intec² 26CE, Intec² 30CE, Intec² 35CE
GC 47-532-66, 47-532-67, 47-532-68
Chimney Sweep Mode (Combustion Check Mode)
- Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output depending on the position of the central heating thermostat knob.
- The parasol and snowman symbols will flash at the same time to indicate this mode.
- Manually control the boiler output by turning the Central Heating control knob from the minimum CH output to the maximum CH output (display shows percentage from 00 minimum to 99 maximum).
- This mode remains active for fifteen minutes or can be cancelled by turning the boiler off.
From manual 1.035665, page 28.
Entering Parameter and Service Setup Menu
- Set the DHW selector to 6 o’clock and the CH selector to 9 o’clock.
- Press the 'RESET' and 'Summer/Winter' buttons simultaneously for about 8 seconds to access the parameter menu.
From manual 1.035665, page 30.
Full Calibration / CO2 Set Up Procedure
- Turn the DHW selector to 6 o'clock and the CH selector to 9 o'clock.
- Press the 'RESET' button for eight seconds until the parasol and snowman flash at the same time (chimney sweep mode).
- Press the 'Summer/Winter' button within three seconds to enter the setup menu.
- Adjust flue gas CO2 levels at maximum DHW (99%), medium, and minimum (00%) output levels using the 'Standby' and 'INFO' buttons.
- Press the reset button to store the setting and the 'Summer/Winter' button to save and exit.
From manual 1.035665, page 30.
Fast Calibration Mode
- Turn the DHW selector to 6 o'clock and the CH selector to 9 o'clock.
- Press the 'RESET' button for eight seconds until the parasol and snowman flash at the same time (chimney sweep mode).
- Press the 'INFO' button within three seconds to activate fast calibration.
- The boiler will automatically calibrate across max, med, and min heat output values and exit automatically.
From manual 1.035665, page 31.
| Model | Gas | CO₂ max rate | CO₂ min rate | CO max |
|---|---|---|---|---|
| Intec² 26CE, Intec² 35CE | Natural gas | 9.2% ± 0.8% | 9.0% ± 0.8% | 200 ppm |
| Intec² 26CE, Intec² 35CE | LPG | 10.5% ± 1% | 10.0% ± 1% | – |
| Intec² 30CE | Natural gas | 9.2% ± 0.8% | 9.0% ± 0.8% | 200 ppm |
| Intec² 30CE | LPG | 10.8% ± 1% | 10.0% ± 1% | – |
CO₂ and CO from manual 1.035665, page 4. Check against the data badge.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is recommended or required the engineer must be competent to carry out this work. (page 28)
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Common questions
Is service mode the same as chimney sweep mode?
Yes, in practice. Makers use different names for the same function: service mode, chimney sweep mode, test mode, calibration mode, check programme. Each one holds the burner at a fixed rate, usually maximum then minimum, so you can take a stable combustion reading.
Can I adjust the gas valve while it's in service mode?
Only where the manual gives an adjustment procedure, and only with an analyser in the flue. Many current boilers are set at the factory and the manual says not to touch the gas valve. Where a manual says that, it is shown with the procedure above.
Other makers
AristonAtagBaxiBiasiChaffoteauxFerroliGlow-wormHalsteadHeatlineIdealIntergasJohnson StarleyKestonMainPottertonRemehaSimeVaillantViessmannVokeraWorcester Bosch
Service mode and combustion checks are work for a competent, Gas Safe registered engineer. These procedures are taken from the manufacturers' manuals and inform your judgement; they don't replace it. Always work to the manual for the exact appliance, its data badge and the current standards.