Evohome thermostat pack

[Rallye90]

Excuse my ignorance, Im a user, but i have fitted a control unit (ATC928) and a (BDR91) wired to a Worcester combi boiler and at the moment l have 3 Zones for my 3 bedrooms using HR92valve control units, ,and the main control unit as the temperature controller for the rooms downstairs at the moment,until l can purchase more HR92<s.
The HR92 seem to work perfectly as the temperature upstairs is fine, matching the set temp and the reading on the screen. The main unit is set at 21deg Cel. and very rarely hits that temp, it seems to want to turn off at about 19deg,s but only seems to reach that temp when on day off after a long period of time.
Initially l did use the main controller on its own before l had chance to fit and bind up the HR92's, in this mode the down stairs had no problem at all in reaching the required temp.
Does anybody have any ideas on what may be wrong?

[Richard]

The evohome system was not designed to be used in the way you have applied it and hence it isn't working... If you had purchased the system from us I would explain further, but sadly I cannot find your details on our system. Maybe contact Honeywell technical support and they can explain further - 0300 130 1299.