Deliming Solvents; Tank Cleanout Procedures - A.O. Smith BTI 120 Installation & Operation Manual

FIGURE 15

DELIMING SOLVENTS

A. O. Smith recommends the use of UN•LIME for deliming.
UN•LIME is a patented food grade acid which is safe to handle
and does not create the harmful fumes which are associated
with other products.
UN•LIME may be obtained from your dealer, distributor or the
A. O. Smith Product Service Division. Order Part Number 4763,
1 gallon, packed 4 gallons per case or Part Number 4813,
5 gallon container.
NOTE: Un•Lime is not available for use in Canada
Hydrochloric base acids are not recommended for use on glass
lined tanks.
Observe handling instructions on label of product being used.
TANK CLEANOUT PROCEDURE
The following practices will ensure longer life and enable the
unit to operate at its designed efficiency:
1. Once a month the heater should be flushed. Open the drain
valve and allow two gallons of water to drain from the heater.
Inlet water valve should remain open to maintain pressure in
tank.
2. A cleanout opening is provided for periodic cleaning of the
tank. Gas must be shut off and heater drained before opening
cleanout.
To clean heater through cleanout opening, proceed as follows:
1. Drain heater.
2. Remove outer cover plate from lower side of heater jacket.
3. Remove six (6) hex head screws securing tank cleanout plate
and remove plate.
CAUTION
4. Remove lime, scale, or sediment using care not to damage
the glass lining.
5. Inspect cleanout plate gasket, if new gasket is required,
replace with A. O. Smith part no. 99038.
6. Install cleanout plate. Be sure to draw plate up tight by
tightening screws securely.
7. Replace outer jacket cover plate.
In some water areas the sediment might not be removed by this
method and may result in the water heater making rumbling or
boiling noises. To dissolve and remove these more stubborn
mineral deposits, A. O. Smith UN•LIME Professional Delimer
should be used.
DELIMING USING FLO-JUG METHOD
UN•LIME in the 5 gallon size is recommended for deliming of
the BT-80 100 models. UN•LIME with the necessary hoses and
fittings to delime your heater is also available as a kit:
Up-N-Down Transfer Kit. Contact your local A.O. Smith dealer,
distributor or, A.O. Smith Water Products Company:
Telephone: (800) 433-2545
Fax: (800) 433-2515
Website: www.hotwater.com/parts
Prepare the Water Heater
To delime the water heater using the Flo-Jug method, first
prepare the heater for deliming as described in the "Why? When?
and How?" booklet, Form No. 4800. Then install the long plastic
male adapter fitting into the drain valve opening of the water
heater. Use teflon tape and hand tighten only. Do not overtighten.
Prepare the Up-N-Down Transfer Kit
The next step is the preparation on the Up-N-Down Transfer Kit,
if you have not already done so:
1. With the 5 gallon Up-N-Down container in the vertical position,
unscrew the plastic vent cap in the handle and pierce the
plastic membrane over the vent boss under the cap to allow
the container to vent.
Note: If your container does not have the vent cap and vent
boss, drill a 3/16" hole in the handle. When you have finished
deliming you will be able to plug this drilled vent with the
stainless steel screw that is supplied with the kit.
2. Remove the container's cap and cut the plastic membrane
located in the 3/4" IPT opening in the cap. Take care to not
damage the threads.
3. Find the 3/4" male adapter, apply teflon tape to the threaded
end and screw it into the 3/4" IPT opening in the cap.
4. Put cap with male adapter back on the container and slide
3/4" hose over end of male adapter and fasten in place using
hose clamp provided.
Delime using Flo-Jug Method
5. Slide the hose clamp over end of hose and slide hose over
the male adapter in the water heater drain opening and
secure in place using hose clamp.
6. Lift container to the "Pour" Position, see Figure 16, being
careful to keep the vent in the handle above the liquid level
and pour the UN•LIME into the heater.
28