Drayton Wireless System RF1 / Worcester Boiler?

I have a Drayton Wireless System RF1. The thermostat is apparently working well: it indicates the temperature and has that sign of a flame on it. The receiver however displays NO lights at all -- it seems that it is off, with no power running through it.

Despite that, the water is heating. Can I somehow override the wireless system and control the temperature through the worcester device?

Does anyone know how to fix it? I am freezing.

Thank you!