Caleffi solar NAS200 Series, Installation, Commissioning And Servicing Instructions

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SECTION VII: TROUBLESHOOTING
Undersized solar collectors Calculate proper collector surface area, orientation, and
available sunlight.
Check power supply
PROBLEM CAUSE SOLUTION
ECO on thermostat tripped Determine cause of ECO trip (solar heat or electric
element). Correct or replace as necessary. Reset
thermostat (depress red button).
Determine peak usage, compare to tank capacity, and
add additional storage (storage tank) if necessary
Improper thermostat setting Turn thermostat to safe temperature setting
Electrical problem (relay, wiring, etc.) Check fuse and replace
Check circuit breaker and reset (if applicable)
Check power supply
Thermostat set too low Raise thermostat setting to safe level. See Section V
No hot water at faucet
Water at faucet too hot Thermostat set too high Lower thermostat setting to safe level
Tempering valve not properly set or defective Check manufacturers instructions
Scale build-up If boiler, circulator, and tank are operating satisfactorily,
coil may have scale coating. See Section VI for tank
flushing procedure.
Circulator does not operate
Check solar controller
Replace as necessary
Faulty tank thermostat Replace thermostat
Insufficient hot water
Rust staining; bad taste and odor in
water Iron/minerals in water supply Filtration
Scale, hard white particles from
faucets, popping sound from tank Lime, water hardness above 7 grains-120ppm Water treatment; softener; etc.
Undersized boiler with no priority to domestic
hot water Rewire for priority
Peak use of hot water is greater than tank
storage capacity
Rotten egg odor Hydrogen Sulfide Flush tank with chlorine solution and install aluminum
anode rod(s)
Air from hot water fixture Electrolysis or air introduced by water supply Properly ground heater & replace anode rod(s). Check
well pump system.
Reduction in recovery Dip tube broken or compromised by high
chlorine in water Replace dip tube
Inlet/Outlet fitting corrosion Galvanic corrosion of dissimilar metals Install dielectric unions
T&P gushing water Excessive water temp. (above 210 °F) Adjust or replace thermostat and T&P valve
T&P Valve dripping water Excessive water pressure (above 150 psi) Check incoming water supply pressure; closed loop
system requires expansion tank