While you wait for answers, we may have found some information which could help you.
Success
Message
Horstmann channel plus. The water is on all the time?
Horstmann channelplus model H37 - ch won't come on?
setting clock of economy 7 horstmann boiler?
Standy by battery on Horstmann H37 XL Progammer?
Fix?
horstmann ChannelPlus H37XL?
Whats wrong with my Vokera Mynute EHE boiler?
horstmann channel plus h 37 xl?
Horstmann Economy 7 problem?
does the battery control my horstmann eco7 timer?
horstmann economy 7 heaters not coming on?
wiring horstmann centaurstat 7?