Alarm 3 Supply air temperature below 5 degrees, flashing 3 on the control panel.
Check that the reheating coil is not switched off, parameter 31 should be in the ON position.
Are airflows adjusted, measured by an adjustment expert?
The exhaust air flow should be slightly higher than the supply air flow. See brochure and parameter list, check parameters 11 to 18 which are fan settings. Are filters very dirty? Check special exhaust air filter and change if necessary.
At A70T, if basic flow in kitchen is taken via cooker hood, this leads to lower heat recovery and problems to keep the right supply air temperature at low outdoor temperature
Check the damper disc in the cooker hood by removing the filter, the damper disc should close tightly when the damper control closes the damper in the hood. There should be no opening in the damper disc, tape up the opening to urgently solve problems with low supply air temperature, basic flow in the kitchen should be taken via a separate exhaust air device and not via the cooker hood
Will alarm at high outside temperature ? Replace black relay on circuit board by loosening wire jumper.