Button combinations: Boiler tips

Short, practical technician tips on button combinations for boiler. Check each one against the manual for your exact model before acting.

Lock or unlock the key pad

Bosch · Greenstar ZBR/ZWB 21-42-3A wall-hung boilers and ZWB 28-42-3A combis

The key pad lock blocks the high limit dial, the DHW thermostat and every button except ON/OFF, emissions test and reset. A lock symbol alternates with supply temperature when on.

1. Keep pressing the key pad lock button until the lock symbol alternates with the supply temperature
2. To unlock, keep pressing the same button until only the supply temperature shows

Front panel button functions for editing

Glow Brand · All C95 and C140 units

The four-button console is used the same way in the user, information and installer menus.

1. RESET/ENTER opens the main menu, selects a parameter, and saves a changed value.
2. DHW up and DHW down move through menus and change a flashing value.
3. CH up or CH down exits the menu or cancels an edit without saving.
4. Press CH up or CH down twice to exit the Information Menu.

Navigate the menus

Glow Brand · B85, B120, B160 (NG and LP)

Four arrow buttons plus RESET/ENTER drive the whole control.

1. RESET/ENTER once = main menu; DHW up/down moves between 0.000 (user), 1.000 (information) and CodE.
2. Select a parameter with RESET/ENTER; the value blinks; DHW up/down changes it; RESET/ENTER stores it.
3. CH up or CH down cancels an edit or goes back one level.

Navigating the control menus

Glow Brand · C95 & C140

Button use for moving through the menus and editing values.

1. From the main screen, press RESET/ENTER once to open the Main Menu.
2. Hold RESET/ENTER for at least 2 seconds from the status screen to reach the overview or reset a lockout.
3. Use DHW up/down to move through menu items; press RESET/ENTER to select.
4. Use CH up/down or the exit function to go back one level.
5. Press RESET/ENTER on a parameter to make it blink, change it with DHW up/down, then press RESET/ENTER to store.

Test mode and test function buttons

NTI · TRX150 and related TRX models

Test Mode is used for gas inlet pressure checks. The Test Function is used to set the burner at max or min power.

1. Hold RESET for 10 seconds to enable Test Mode. The display shows a test icon.
2. Hold RESET for 10 seconds again to activate the Test Function. Max and min power are selected with the buttons shown in the combustion procedure.
3. To exit, press RESET. The Test Function also times out after 30 minutes.

View the last nine error codes (DHW + Up)

Rinnai · I-Series Plus Solo (heat-only) boilers IP060S, IP090S, IP120S, IP150S, IP175S, IP199S

Shows the stored error history on the I-Series Plus controller.

1. Hold the DHW button for 2 s, then press Up as well (both together).
2. Repeat the same press to exit.