27
LP-200 REV. 1.6.15
performance of the solar water heater and cause overheating of the collector system. You must install a mixing valve on the hot water
outlet, as temperature within the storage tank can cause injury.
PART 9 – SERVICE/MAINTENANCE PROCEDURES
A properly maintained solar water heating system can provide years of dependable, trouble-free service. It is suggested that a routine
preventive maintenance program be established and followed by the end user with the solar contractor. Listed below is the
maintenance check list that outlines the primary components of the solar system that need to be inspected annually.
1. HTF Glycol (if used)
– It is very important that the quality of the glycol is maintained to avoid damage to the collector loop and related
components. See the manufacturer’s data sheet for further details.
2. Water quality can affect the operation of the solar heat exchanger over time. In very hard water areas, it is recommended to drain
(#14) a few gallons of water from the bottom of the tank to keep the water heater free of sediment.
3. Clean and inspect the solar collector (#1). Dirt or film may settle on the surface and affect performance. Check collector supplier for
cleaning procedures.
4. Check piping and component insulation for deterioration.
5. Check solar tank sensors and the boiler back up aquastat sensors (#’s 15 and 23). Assure these sensors are secure and have not
moved or loosened.
6. Inspect the T&P valve (#19) on the water heater. Lift the release handle lever. Make sure discharge is directed to an open drain.
Never open the pressure relief valve while the system is in operation or hot water is present. Allow to cool prior to opening.
7. The area near the water heater must be kept free of flammable liquids such as gasoline, paint thinners, adhesives, or other
combustible materials.
8. The electric element may need cleaning. A hissing sound while operating indicates the element has built up deposits. Cleaning
should only be done by a qualified plumbing or heating contractor.
If the heating element needs replacement, it is VERY important to use the same voltage, wattage, and construction. This element must
be stainless steel and the hex plug be made of brass. This replacement part is available from HTP and should not be purchased from
outside sources.
A. SHUTDOWN PROCEDURES
The solar system is designed to be easily isolated for emergency repairs or routine maintenance. To isolate the water heater, simply
shut down supply water shut off valve (#24) which isolates the water heater from the pressurized cold water supply.
The collector loop can be isolated from the solar storage tank by closing (#6 and #11). If the pressure in this loop drops, or you find a
glycol leak, shut these valves and contact your installation contractor. Turn the circulating pump off on your solar control.
B. VACATION SHUTDOWN
Solar water heaters can build up very high temperatures when there is no daily draw on the system. The best way to dissipate heat in
the system is set the control to run the circulator pump 24 hours a day to cool off the storage tank at night. The collector will radiate
heat back to the atmosphere at night, preventing the system from stagnating at very high temperatures.
C. ESTIMATED LIFE OF COMPONENTS
Proper care and maintenance will determine the life expectancy of the individual components of the solar system. Refer to
manufacturer’s warranty information to determine coverage of individual components. To obtain warranty service, call your local service
or installing contractor.
D. TEMPERATURE AND PRESSURE RELIEF VALVE
A temperature and pressure relief (T&P) valve is designed for emergency safety relief and shall not be used as an operating control. A
T&P valve functions by discharging water in an emergency. Therefore, it is essential that a discharge line be piped from the valve in
order to carry the overflow to a safe place of disposal. The discharge line must be the same size as the valve outlet, must pitch
downward from the valve, and terminate at least 6” above a drain where any discharge will be clearly visible.
