Remote control displays an error
There is a fault within the unit and a service call is required.
Temperature cannot be changed on the remote controller
Priority button may not be set. Check if priority light is lit, if not turn off all hot taps and press the priority button. You should now be able to adjust the temperatures. 
Remote control has no display
The power to the gas continuous unit may be switched off or the connecting wires from remote to unit are not connected. 
Vapour or steam coming from the hot air outlet of the unit
This is normal and can happen on cold or wet days as the unit can generate steam or vapour when the unit is heating. 
No hot water or water is not hot enough /no power or gas to gas booster
Check power switch is on or gas supply is not turned off to the gas booster .
Water is cold or not hot enough when taps are turned on
Check the power switch is switched on and check the gas supply to the gas booster is not turned off. If remote is fitted check it is switched on. If there has been loss of power remote will need to be reset. 
Water temperature fluctuating
The cold water inlet filter maybe restricted. Remove filter and clear obstruction (refer to user manual).