Flexicom 30sx - boiler error?

When there is demand the Glowworm Flexicom 30sx cycles through burner on, then state codes 98 and then 97 before going back to burner on mode. There is no error code and this cycle continue when ever there is DHW or CH demand. How can I stop this cycle from happening? The pump has been replaced and has made no difference. The system is full and bled and up to pressure.