PVI Industries MAXIM INTEGRATED WATER HEATING SYSTEM User Manual

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1.  Establish a preventive maintenance program to 

assure a longer water heater life. 

 

2.  The tank should be flushed at two- or three-

month intervals depending on water conditions 
in your location. To flush, turn off electrical 
disconnect switch to prevent the burner from 
operating. Open the drain valve and allow 
water to flow through the tank until it runs clear. 
Close the drain valve and turn the electrical 
switch back on. Draining two or three gallons 
from the bottom of the tank on a weekly basis 
will also help prevent the accumulation of 
sediment. Water impurities consist of fine 
particles of soil or sand which will settle out 
and form a layer of sediment on the bottom of 
the tank. 

 

3.  A scale of lime will normally form during 

operation and will accumulate on the bottom of 
the tank. Lime is formed from the natural 
chemicals in the water which precipitate out 
during heating cycles. Some water supplies 
contain more of these chemicals than others 
and scale buildup will occur more rapidly. 
Other factors affecting scale buildup are the 
amount of hot water used and temperature of 
the water. The more hot water used, the 

more  fresh water containing scale-forming 
chemicals is brought into the tank. As the 
temperature of water increases, the rate of 
scale deposition will be increased. 

 

4.  The tank will have a handhole for inspection 

and cleaning. (See Figure 17-1, page 1.)  To 
inspect tank for scale buildup, remove the 
handhole cover. If scale is present, it can be 
loosened with a high pressure stream of 
water. The smaller pieces can be flushed 
through the drain and the larger pieces 
removed by hand through the handhole. The 
frequency of inspections will be determined 
by the rate of scale buildup. Intervals of 30-
60 days is recommended. 

 

5.  If a firetube leaks for any reason, consult 

factory for instructions.  

 

 

6.  Regularly inspect the bottom tubesheet.  

Inspect the SCALEGUARD



 

tubesheet 

insulator for holes or areas that may have 
pulled away from tubesheet. Repair or 
replace as required. 

 
 

 

 

 

 

Periodic inspection and check-out of the burner ignition, control system, and fuel valve operation 
(for tight close-off) should be made. Refer to the burner installation instruction for 
recommendations. 

 

1.  Examine the venting system at least once each 

year for proper connections, alignment and 
corrosion. The  blower inlet will collect dust 
from the air during operation. Disconnect the 
power to the heater and clean the blower 
wheel when necessary.  

Inspect all parts and make replacements when 
necessary. Check wiring for loose connections 
and burned wires.