PVI Industries QUICKDRAW PV500-26 - Manual (Page 10)

QUICKDRAW

Boiler Water Heater
10
PV500-26 06/12
5. In all installations, there should be no pulsation or water hammer since this causes vibration and strain with
resulting leaks.
6. Retighten bolting on all gasketed joints after the heat exchanger has reached temperature to prevent leaks and
gasket failures. Retightening should be done uniformly and in a diametrically staggered pattern (see
“Maintenance”).
a. On high pressure and high temperature applications or any application where spiral wound gaskets are
required, it is recommended that the gasketed joints of the heat exchanger be retightened to the required
torque (see “Maintenance”) after 24 hours at operating pressures and temperatures to compensate for any
relaxation or creep that may have occurred.
b. In shutting down, remove all power from the system. Close all boiler water and cold water supply valves to
the unit.
c. If the unit is removed from service for an extended period of time, it must be drain completely to eliminate
the possibility of freezing and corrosion from stagnant water conditions.
7 MAINTENANCE
WARNING: Turn off all electrical service to the appliance when accessing the remote connections located
inside the control cabinet. These terminals are High Voltage. If the electrical service is not turned off and
these terminals are touched, a dangerous shock causing personal injury or loss of life could occur. Close
and fasten the control cabinet cover before restoring electrical service to the appliance.
7.1 Temperature and Pressure Relief Valve
Operate the temperature and pressure relief valve at least once a year by lifting the lever briefly. If the valve does
not open and close properly when testing, it must be replaced with a like relief valve.
7.2 Thermostats and Temperature Limiting Device
The temperature limiting device and thermostat temperature sensors extend into the water in the tank. Depending
on the water conditions in your area, scale may coat the sensors. This coating will affect accuracy of sensors and
can allow water temperature to exceed the desired limits. Remove and inspect these controls at necessary
intervals. Remove scale if present.
7.3 Control Valve Actuator
The boiler water control valve actuator is sealed and requires no maintenance. Durability of valve stems and
packing is dependent upon maintaining non-damaging water conditions. Inadequate water treatment or filtration can
result in corrosion, scale, and abrasive particle formation. Scale and particulates can result in stem and packing
scratches and can adversely affect packing life and other parts of the Hydronic system. Contact the manufacturer
for replacement packing and stem & plug assembly.
7.4 Tank
Scale will normally form in the tank during operation and will accumulate on the bottom of the tank. The natural
chemicals in the water forms scale which precipitate out during the heating cycles. Some water supplies contain
more of these chemicals than others do, and the scale buildup will occur more rapidly. Other factors affecting the
scale buildup are the amount of hot water used and the temperature of the water. The more hot water used the
more fresh water containing the scale-forming chemicals enter into the tank. As the temperature of the water
increases, the rate of scale deposited also increases. The frequency of inspections will be determined by the rate of
scale buildup. Until the appropriate inspection and cleaning frequency is established, initially inspect the tank every
six months or more frequently if higher scaling conditions are present.
Flush the tank at two or three-month intervals depending on water conditions in your location to help prevent the
accumulation of scale. To flush: turn off electrical disconnect switch to prevent the unit 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.
NOTICE: Since PVI cannot control the use of the water heater, water conditions, or maintenance, the warranty on
the water heater does not cover poor performance, structural failure, or leaking due to an excessive accumulation
of scale.