Do you mean a Revenheat CS80 Combi Boiler? One of these:
https://ravenheat.co.uk/products/cs80-combination-boiler/
Note there are two manuals available for download from that page.
If there are (is?) no lights at all and nothing on the display, that suggests there is no power getting to the boiler. check the thing isn't switched off at the supply!
How old is the boiler? These have a 2 year warranty.
asfcdsaf, September 2017
