Specifications
Installation & Maintenance Manual__________ 
52
14.2 ALARM CODES 
controller  code for  cause  solution to the problem  result  reset  alarm 
H  remote Carel 
Humivisor 
  attempt these fixes once; if the problem 
persists contact Carel service personnel 
    relay 
E503 
the PTC sensor in the vent 
has measured an over-
temperature condition 
shut off the humidifier, check the 
water level, clean the steam 
generator and burner 
shut down  Power 
ON/OFF 
active 
E504 
low level of water in the steam 
generator or level control fault
check the water feed connections; 
clean the fill valve, the level control, 
and the steam generator 
shut down  Power 
ON/OFF 
active 
E505 
high conductivity of the feed 
water 
Shut off the unit and clean the 
conductivity probes; if the problem 
persists, change the source of the 
water or install a water treatment 
system (partial demineralization) - the 
problem will not be resolved by the 
addition of water softeners. 
shut down  Power 
ON/OFF 
active 
E511 
autotest failed; probably a 
problem with: filling, draining, 
or level control of the water 
check that the unit is able to fill with 
water; 
check that the unit is able to drain 
water; 
shut off the unit and clean the fill 
valve, the drain valve, and remove 
and replace the water filter. 
disable 
humidifier 
Power 
ON/OFF 
active 
E513 
power not available; unit is 
not attaining required steam 
production or water preheat 
check gas pressure; check fan 
operation 
disable 
humidifier 
Power 
ON/OFF 
active 
E514 
lack of feed water 
Check the feed water lines to the 
humidifier externally and internally to 
make sure they are not blocked or 
kinked; 
verify that the fill solenoid is working; 
make sure there is not excessive 
pressure in the steam distribution 
preventing the gravity fill into the 
steam generator; 
verifiy that there are not bends or 
other places condensate can build up 
in the steam distribution piping 
disable 
humidifier 
Power 
ON/OFF 
active 
E515 
Formation of foam in the 
steam generator during steam 
production. 
The formation of foam is usually 
cause by chemicals in the water 
(solvents, lubricants, detergents, 
water-treatments, water softeners) or 
heavy concentrations of dissolved 
salts. Bleed the water feed lines and 
clean the steam generator. 
warning automatic not active
E517 
Blower error; 
 exhaust or inlet pipe 
obstructed; manual gas valve 
closed; flame sensor 
electrode touching the burner 
grid; blower doesn’t follow the 
speed reference. 
switch off the machine: 
Check for obstructions in vent 
exhaust piping; check that gas valve 
is open; remove the blower and check 
operation. 
disable 
humidifier 
Power 
ON/OFF 
active 
E531 
pre-alarm for high conductivity 
feed water 
check the conductibility of the feed 
water; 
if necessary install water treatment; 
the problem will not be resolved by 
the addition of water softeners. 
warning automatic not active










