Help · Installation
Fitting the sensors
Where the red and the white probe go, why thermal paste and the insulation sleeve are not optional, and how you check for each sensor that it is measuring.
Each hot water installation gets a sensor with two probes: the red probe for hot water and the white probe for cold water. The sticker on each sensor says which building it belongs to, with the same name as in the app. Stick to that layout and your logbook is right from the start.
Where the red probe goes
On the hot pipe coming out of the water heater, before the first branch, at least 2 metres from the water heater and not on a bend. All the hot water of the installation flows past there. When someone opens a hot tap anywhere in the building, the sensor sees it at that spot. That is how your flushing evidence per flushing round comes about. See Recording a flush with the tag.
If the installation has a circulation pipe, the red probe goes on the circulation. That pipe is always hot; the sensor then monitors whether the loop stays at temperature. See Circulation and the loop.
Where the white probe goes
On the cold supply, within 1.5 metres of the red probe, as far as possible from the water heater. A plant room is often warmer than 25 degrees. If that is not possible there, your installation card shows a different spot, or the cold measuring point was switched off when the site was set up.
How to fit a sensor
- Choose the spot shown on your installation card: red on the hot pipe out of the water heater before the first branch, white on the cold supply.
- Clean and dry the piece of pipe. Put a pea-sized amount of thermal paste on the head of the probe. Do not skip this: without paste and insulation every surface-mounted sensor reads consistently too low.
- Clamp the probe tightly onto the pipe. Firmly hand-tight is enough.
- Slide the insulation sleeve over the probe and the clamp and press it down. The sleeve makes sure the probe measures the pipe, not the room.
- Fix the sensor box to the wall with an adhesive strip or to the pipe with a cable tie, with the antenna clear of metal.
Checking that it is measuring
Open Readings in the app. The first reading usually appears within half an hour. You check whether the red probe is in the right place with the placement check on the activation page: open a hot tap in that building and press "Start the check". See Activation and the placement check.
Tricky situations
- Concrete or steel in the way: check that the sensor sends a reading before you fix everything in place, and place the antenna higher.
- Unsure about the spot: send a photo to support@legiolog.nl and we will take a look.
- Combi boiler, heat pump or district heating: there the spot looks different from the drawing. See Hot water source and heat pump.
If nothing comes in after half an hour, see A sensor sends nothing.