Smarter Heating & Hot Water

How to adjust the flow temperature on a Vaillant ecoTEC new type

The current ecoTEC plus, with the black display and the silver panel. This covers the flow temperature you set on the screen, and the maximum heating output a Gas Safe engineer sets in the installer menu.

Vaillant ecoTEC plus with a black display and a silver panel underneath.
ecoTEC plus new type. The steps below are for the 610, 615, 620, 625, 630 and 635 system boilers, and the 826, 832, 836, 840 and 940 combis.

Vaillant’s operating instructions (0020308119) are the homeowner manual. The heating output is in the installation and maintenance instructions (0020308118).

Flow temperature

The flow temperature is the temperature of the heating water as it leaves the boiler. On this range it can be set from 30°C to 80°C. The factory setting is 75°C.

Controls that are lit in colour can be pressed. Change a number by tapping the top or the bottom of the scrollbar. A new number is saved only after you press the flashing control to confirm. The menu dims after 60 seconds, and the status display comes back after another 60 seconds.

If a system control or a sensoROOM pure (VRT 50/2) is connected, set the heating temperature on that control. The boiler will not take the heating temperature on its own screen. If the panel asks for a code, a competent person has locked it.

With no system control:

  1. If the status display is showing, press the control that opens the basic display.
  2. From the basic display, press the heating control. That is the control for the flow temperature. The temperature already set is shown.
  3. Set the flow temperature with the scrollbar.
  4. Press the flashing control to confirm.

Holding the heating control for at least three seconds switches heating off (summer mode), unless a sensoROOM pure is fitted. In that case, heating is switched off by setting the room control to its lowest target, 15°C.

If this boiler heats a cylinder, do not set stored hot water below 60°C without asking a competent person. The operating instructions say the same about water temperatures below 60°C.

Heating output

The maximum heating output is diagnostics code D.000, “Maximum load in heating mode”. The factory setting is Auto, which lets the boiler match its maximum heat input to what the system is asking for. A fixed number in kilowatts is used when the heating output should be capped to the heat loss of the house.

Vaillant puts this in the installer level, and says that level is for a competent person. The code is 17.

  1. Open MENU, then SETTINGS, then Installer level. Enter 17 and confirm.
  2. Open Diagnostics codes.
  3. Select D.000 with the scrollbar and confirm.
  4. Set the kilowatts, or leave Auto, and confirm.

D.071 is the highest heating flow temperature the boiler is allowed to target. It will not go above that limit in heating mode.