OK heres my idiot guide to 'binding' the 2 units together. Forward:
Don’t panic it’s easy to reset but follow the steps carefully and I’ve also wrote a quickie version at the bottom.
This thermostat comes in 2 parts
1: The receiver unit which is hardwired/connected to the boiler itself and this will be mounted close to the boiler (normally just under or to one side).
2: The remote thermostat/programmer which is usually mounted on the living room wall.
The receiver unit has 2 led lights on it. The top one should always be green. The lower one will turn amber when the thermostat talks to the receiver to turn the boiler on. When the amber light is on the boiler should be working.
If the top light is red there is a problem, normally for some reason the thermostat has lost its connection to the receiver.
1: Fit new batteries to the thermostat 2 x AA (located at the bottom of the thermostat unit). Does it now work and is the TOP light on the receiver unit green? If yes ok, job done, if not continue down the list.
2: Remove the thermostat unit from the wall by first partly removing the bottom small pozi screw (no need to fully remove). Pull the unit away from the wall bracket from the BOTTOM, if it does not come remove the screw some more. When it comes away at the bottom lift it off the top bracket hinges no need to use any force at all.
3: Take the unit to the boiler and make sure the front switches on the thermostat unit are set to AUTO & RUN
4: Turn the boiler off at the BOILER switch located on the BOILER and NOT the main power switch or you will turn the power off to the receiver also and you will fail.
5: You will see 2 buttons on the receiver unit.
1: the top one is called the Override button
2: the very small bottom one is called the learn button.
6: Press and HOLD the top ‘override’ button and at the SAME time press and HOLD the bottom ‘Learn’ button. You may need a pen to push the small ‘Learn’ button in. KEEP BOTH HELD IN FOR 4 SECONDS and you will see the top led light flash, release both buttons.
7: Next press & hold just the ‘learn’ button on the receiver for 2 seconds.
8: Next, on the rear of the thermostat unit there are 2 buttons.
1: =Test
2: = Learn
Press & HOLD the ‘learn’ button for 2 seconds (a pen maybe required once more). The 2 units should now be synchronizing; this will take 10-30 seconds. Give it time and do not press anything.
9: The led light on the receiver should now be GREEN. You’ve done it. Turn the boiler back on and all should be ok. Refit the thermostat unit by hooking the top of the unit back onto the top wall brackets and lowering the unit back onto the lower securing lug. Carefully tighten the bottom screw.
Quickie Guide
1 Ensure the thermostat unit is set to Auto and Run
2 Turn boiler off on the boiler switch not the main fused spur point.
3 Press both receiver buttons at the same time and hold for 4 seconds
4 Press just the learn button on the receiver and hold for 2 seconds
5 Press and hold the learn button on the thermostat for 2 seconds
6 wait between 10-30 seconds
7 Turn boiler back on.
Dave, December 2018