hortsmann serviceplus s21 lockout problem

[rob downie]

hi new to this forum, have a client whose serviceplus s21 has locked out from his system due to a service which he had already done over 3 months ago but engineer never reset his programmer (probably didnt know how to), is there anyway a code or sequence that can reset the programmer? ive tried the set and ch buttons held together and release still keeps saying "call eng 0 days", hes also tried getting the code of the local housing association who he purchased the house off over a year ago but they wont release any information, any help please. thanks.