breaker plug should be used.
7. The flow reverser handle points
in the direction of flow of the
liquid. Operate the handle so
that initially it points towards
the hose connected to the lower
connection to the humidifier
bottle.. The hose from the top
of the bottle will then be the
return to the descaling pump
tank.
8. Add descaling chemical to
pump tank, switch on pump,
and commence circulation. If
water level drops, check that all
connections are tight.
9. Once descaling liquid is
returning into the descaling
pump tank from the humidifier
bottle, check if there is a build
up of foam on top of the liquid
in the pump. This may happen
when there is a large amount
of reactive limescale in the
bottle. If this is excessive, add
FOAMBREAKER carefully to the
tank to reduce the foaming. If
the bottle is heavily scaled, add
10cc of FOAMBREAKER before
adding the descaling chemical.
10. As circulation commences,
bubbles will be seen in the
return hose, indicating that
limescale is being dissolved.
11. Continue circulation through
the humidifier bottle and
descaling pump, briefly
reversing the direction of flow
periodically.
12. Check connections regularly
for tightness, and leaks, and if
foaming is excessive, carefully
remove descaling pump tank cap
and add more FOAMBREAKER to
the descaling pump tank.
13. Scale removal can be considered
complete when bubbles are no
longer seen in the return pipe,
and the descaling solution is still
sufficiently strong to remove
hard water deposits.
SCALEBREAKER descaling chemicals
contain a built-in colour change
to monitor strength. A simple
check may be made by dropping
a sample of limescale into the
solution, and observing if there
is any effervescence.
14. Alternatively a pH meter, or pH
indicator paper, may be used to
check the pH of the descaling
solution. Once the pH has risen
to 3.5 to 4, its ability to dissolve
limescale is effectively spent, and
more descaling chemical or a
fresh solution will be required.
15. If, after descaling has ceased,
the pH of the descaling
solution is still below 5, then
the remaining solution must be
neutralised to bring the pH level
above 5, and as close to 7 as
practicable.
Slowly add NEUTRALISING
CRYSTALS to the tank of the
descaling pump until there is
no more effervescence as the
crystals are added. If foaming is
a problem during this operation,
add a few ml. of FOAMBREAKER
antifoam.
16. After draining off the spent /
neutralised descaling chemical,
flush the humidifier bottle
with fresh water. Many natural
waters are slightly alkaline, and
water flushing may be all that is
required. Alternatively, circulate
a 1% solution of NEUTRALISING
CRYSTALS through the heater
for 15 minutes, drain, and then
flush with clean water once
more.
IMPORTANT: When working with
acidic descaling chemicals, always
wear suitable protective clothing
and goggles. Refer to instructions
on labels of descaling chemicals,
and refer to Material Safety Data
Sheets.
Caps should be kept securely on all
chemical containers whilst not in
use. To avoid splashes, operators
should avoid standing directly over
the open neck of either chemical
containers or the filling neck of the
descaling pump whilst pouring or
adding chemicals.
Legal disclaimer: It is stressed that
these are guidance notes only, and
the above information is based on
the present state of our knowledge
of humidifiers in general. It is
given in good faith, but due to the
diverse and varied nature of such
equipment, the user must satisfy
himself that the above procedure is
viable in the prevailing situation.
