Dunkirk H2OI Stainless Steel Dual Coil Solar Water Heaters - Manual (Page 19)

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VI. Maintenance
The water heater is intended to provide many years of reliable service. Components, such as thermostats and relief
valves, may be subject to failures that require service. Depending on the quality of the water supply, sediment and/or
scale may coat the heating coil in the tank and reduce hot water recovery rate. Failure to use the correct procedures or
parts can result in unsafe operation.
The owner should arrange to have the following inspections and simple maintenance procedures done at the suggested
frequencies.
1. Boiler and Domestic Water Piping (Annual)
Check all piping for signs of leakage at the joints, unions and shut-off valves. Repair as required.
2. Temperature and Pressure Relief Valve (Annual)
3. Sediment (Annual except where harsh water quality may require more frequent service)
Depending on water conditions, a varying amount of sediment may collect in the tank. Levels requiring service
are indicated by a small temperature difference between the boiler supply and return lines, and a reduced
recovery rate. Repeated flushing usually clears such material. As a preventive measure, water should be drawn
from the drain valve until it runs clear and the installation of a water filter should be considered.
4. Scale (Annual)
Hard water may cause scale buildup on the outside of the heating coil inside the tank. A water softener will
prevent this problem. Symptoms are identical to sediment buildup. If repeated flushing does not resolve the
problem, chemical cleaning may be required. Contact a qualified contractor.
VII. Troubleshooting
PROBLEM CAUSE SOLUTION
No hot water at faucets
Boiler does not operate.
Press reset button
Check main cut-off switch
Check fuses or breakers.
Check power supply to boiler.
Circulator does not operate Check power supply to pump.
Improper thermostat setting Turn thermostat to a higher setting.
Zone valve does not open Check power supply and valve
Electrical problem Check fuses and replace.
Check circuit breaker and reset.
Check power supply
Clogged filter Clean or replace filter.
Insufficient or runs out of hot water
at the faucet
Thermostat setting too low. Turn the thermostat to a higher setting.
Undersized boiler with no priority to do-
mestic water heating.
Rewire for priority.
Peak draw of hot water is greater than
the tank storage.
Determine peak usage and compare to tank
volume.
Sediment and/or scale buildup Contact qualified contractor to clean coil.
Faulty water heater thermostat Replace thermostat
Water at faucet too hot
Thermostat set to high Lower thermostat setting.
Improper wiring or plumbing. Compare to installation guide.
Boiler cycles more than 5 times per
day in summer
Excessive demand Reduce demand or consider larger boiler
and/or water heater.
Faulty thermostat Replace thermostat
Boiler high limit set to low Increase boiler hi-limit setting
Sediment and or scale buildup Contact qualified contractor to clean coil.
Faulty water heating element Replace element