There are 2 common reasons as to why this may happen:
● Power - the power source to the display is causing the blank screen
● Physical damage or poor install - damaged hardware or loose connections
This can also be caused by other influences - if you have not managed to diagnose the issue as one of the two above reasons, please phone Switchee Installer Support on 0800 133 7957 for further troubleshooting, and to report the device faulty.
Solution
The first thing you want to check is the power for the whole Switchee equipment. Starting with the Boiler Receiver Unit, check there is a green light above the power symbol to show that the device is powered.
If this green light is present, we know the Switchee equipment has power. If not, please check the connection at the BRU terminals. The image underneath pictures the BRU terminal which draws power from the fused spur.
Please ensure that the terminal block is connected, and not damaged. If you believe that the terminal here is damaged, you can use a multimeter to observe the output of the common terminal when the power is activated. This should be a non-zero voltage. You should also check the quality of wiring, if there are loose wires/connections please replace these with a more secure connection. The next thing to check is the power to the bracket of the thermostat display.
The small green light in the bottom right corner of the bracket indicates whether the bracket is powered or not.
If no green light is found here, it implies that the bracket is not receiving power from the BRU.
To find the source of the fault, the bracket terminals and BRU terminal blocks should be checked. The BRU terminal block for the smaller, 12V output to the thermostat bracket can be found next page.
Check that the terminal block isn’t damaged, and that it is securely connected to the PCB. You can check the terminal block using a multimeter to see if it has been damaged. If you test the 12V terminal, you should expect 12V. You should also check the quality of wiring, if there are loose wires/connections please replace these with a more secure connection.
If the connections on the BRU are okay, then proceed to checking the wiring of the bracket.
The blue terminals in the above image are the terminals on the bracket which connect back to the BRU.
If there appears to be no power to the bracket, please check the 0V and 12V terminals for the quality of the wiring and whether it has been properly secured. If this is looking okay, then check the soldering of the terminals.
If you flip over the bracket, you can see a small black circle on the bracket terminals where these have been soldered on. If this seems loose or damaged, it's very likely that this is causing our issue.
This can be caused by damaging the bracket whilst installing, so if this has happened then be careful when you replace this bracket.
Another good area to check for damage is on the back of the display - where the pins are located. The pins provide a connection for the display into the bracket, and so if these were broken the display would be blank.
To check for damage, simply apply pressure to the pins found on the back of the display. If they move (even slightly) this implies that they have been damaged and will need replacing.
You can also shake the device to gauge whether a connection inside the display has come loose. A very small rattling sound can be heard if the grub screw is left in the display, but if something was loose you should be able to distinguish this as a loose connection or broken component.
For more support, contact installer support directly:
Tel: 0800 133 7957 | Email: install@switchee.com