SM80/5W Installation Manual

Table Of Contents
9
Maintenance
SM80/5, SM100/5 – 6 720 800 156 (2013/06)16
9.1 Preparing the DHW tank for cleaning
Disconnect electrical power from the heating system.
Drain the DHW tank. To do so, close the shut-off valve for cold water
inlet and the open drain valve. To vent the system, open the air vent
valve or the highest faucet.
Remove the cleanout cover [6] shroud over the inspection port [1] in
the DHW tank.
Loosen the hex bolts [5] in the cleanout cover [4].
Remove the cleanout cover [4], magnesium anode [3] and cleanout
cover gasket [2].
Fig. 19 Removing the cleanout cover
[1] Inspection port
[2] Cleanout cover gasket
[3] Magnesium anode
[4] Cleanout cover
[5] Hex bolts
[6] Cleanout cover shroud
9.2 Descaling/cleaning the DHW tank
Check the DHW tank interior for scale deposits (calcium).
Should scale deposits be discovered inside the DHW tank, proceed as
follows:
Hose down the inside of the DHW tank with a "high pressure"
(approx. 58 – 72,5 psi (4 – 5 bar) gauge pressure) stream of cold
water ( Fig. 20, page 16).
You can increase the cleaning effect by heating up the coils in the
drained DHW tank before cleaning. The thermal shock effect releases
scale deposits more easily from the coil-type heat exchanger.
Use a wet & dry vacuum cleaner with plastic suction hose to remove
the residues.
Extremely tough scale deposits inside the DHW tank can be removed by
chemical means. We recommend that you have a qualified contractor
carry out the chemical cleaning operation.
Fig. 20 Hosing down the inside of the DHW tank
9.3 Checking the magnesium anodes
The purpose of the anode rod is to protect the tank against corrosion.
It is critical that the anode rod be inspection once a year to determine
whether it requires replacing.
Upon inspection, the anode rod surface should appear smooth.
If the rod surface appears pitted, bumpy, rusty, scale has built up on the
surface, or if the rod is less than 5/8" (15 mm) in diameter, then it must
be replaced.
Certain installations may require more frequent replacement of the
anode rod:
Recirculation connection
Poor water quality
Galvanic/electrolytic corrosion
High flow applications.
In the event of poor water quality it is recommended that a water
treatment professional be consulted for water treatment options.
Damage resulting from failure to replace the anode rod is not covered
under tank warranty.
Checking the upper magnesium anode
Remove PS top cover if not already removed.
Unscrew the magnesium anodes.
DANGER: Risk of scalding
Hot water can cause scalding.
Prior to cleaning, allow the DHW tank to cool down
sufficiently.
CAUTION: Risk of tank damage due to damaged enamel.
Never use hard objects or tools with sharp edges to
clean the interior of the tank.
6720 800 155-02.1ITL
Failure to service the magnesium anode properly voids
the warranty. Annual service records must be kept in a
safe location and submitted together with the original
purchase receipt in the event of a warranty claim.
Never bring the magnesium anode surface into contact
with oil or grease.
Keep everything clean.