Manual 01 - Section 11







Residential Solar Information Manual
Section 11 - Fault Finding and Service

COMMON COMPLAINTS

GENERAL

This section should be used as a guide to assist in quick location and correction of system faults and customer complaints to ensure Solahart systems retain their position of high performance, quality and service.

The following items represent the most common trouble shooting requirements:

INSUFFICIENT HOT WATER (SOLAR)

This can often be the result of the owner's reluctance to turn on the booster during periods of low solar radiation or high hot water usage. It is essential to establish the facts regarding usage patterns before any investigative work are conducted. Customers may not be aware of issues that can lead to perceived system inefficiency under solar only input conditions.

The situations for consideration are:

Having determined that these conditions are not responsible for the poor performance the following check list may be used to identify the cause.

TROUBLE SHOOTING CHECK LIST

Inspection common to L, J & K Systems

L Systems Only

J & K Systems Only

More Detailed Investigation

DRAW OFF TEST PROCEDURE ( SOLAR BOOSTING)

Before 9 AM draw off all the hot water from the storage tank, turn off cold water and booster supplies to solar hot water system. If the day has been clear return to the system after 4 PM and turn the cold water supply on noting the supply water meter reading before drawing off the entire tank contents into the laundry trough. The water should be drawn one trough at a time with a record made of the temperature and water meter reading after each trough load. The first temperature measured should be approximately twice the daily maximum temperature and at least 75% of the tank volume is drawn before the temperature falls by 12°C from the starting temperature.

INSUFFICIENT HOT WATER (AUXILIARY BOOSTING)

DRAW OFF TEST PROCEDURE ( AUXILIARY BOOSTING)

Turn off cold water supply, allow tank to boost for a minimum of 5 hours on electric or gas(ie. one thermostat cycle). Turn off the booster supply. Note the supply water meter reading before drawing off the entire tank contents into the laundry trough. The water should be drawn one trough at a time with a record made of the temperature and water meter reading after each trough load. The first temperature measured should be approximately 60oC and at least 60% of the tank volume is drawn before the temperature falls by 12°C from the starting temperature.

AUXILIARY BOOSTER WATER VOLUME

The standard electric or gas booster elements heat the top 2/3 of the storage tank so that there is sufficient boosted hot water to meet the customers' demands without seriously affecting the solar energy collection ability. Consequently the night stabilisation effect will be more pronounced when the only source of input energy is the electric or gas booster element because the tank bottom 1/3 is filled with cold water that can only be heated by solar energy.

OFF-PEAK ELECTRICITY SUPPLY

Most off-peak supplies are available only during the night (no daytime boost) therefore the tank can be without any boost energy input from 7 am to 9 PM (ie. 14 hours). During periods of low solar radiation a significant run-down will occur after the early morning hot water usage. Consequently it is strongly recommended that a day rate switch be provided to enable the customer to switch to day rate power for a short period to boost the tank temperature if necessary. It is also advisable to install the electric element sickle down to increase the boosted volume in off-peak installations.

OVER-NIGHT TEMPERATURE STABILISATION

Over-night there is a reduction in the tank hot water outlet temperature caused by heat dissipation into the cooler water stored lower in the tank near the inlet position. The magnitude of this effect is proportional to the amount of water drawn over night (the more hot water used the greater the temperature drop). The outlet heat energy is not lost from the system but is stored in the cooler water lower in the tank. On some occasions it may be necessary to use the electric / gas booster to heat the water in the top of the tank to a useable morning temperature.

If hot water is not used from a 300 litre storage tank the night the heat loss (temperature drop) under average conditions is approximately 5oC (ie. the tank storage temperature 70oC).

As an example if 60 litres of hot water is used during the night the morning tank temperature will be 61.5oC or a reduction of 8.5oC (5oC heat loss and 3.5oC of temperature stabilisation). If 160 litres of hot water were used during the night the morning tank temperature will be 50oC or a reduction of 20oC (5oC heat loss plus 15oC temperature stabilisation)

DIRECT HEAT LOSS

Close coupled thermosiphon solar water heaters similar to Solahart systems have the tank positioned above the collectors and therefore do NOT circulate water between the collectors and tank at night.

Since water in the storage cylinder is warmer than that in the collectors, and as hot water always rises the hot water will remain in the storage tank. As a result there is no night recirculation of hot water from tank to collectors.

The Solahart systems have been independently tested for heat loss with collectors connected. The heat loss tests show that the Solahart systems are significantly better than the minimum value required by the Australian Standard (AS1056). This result has been achieved by the use of specialised insulation injection methods and tank positioning technology.

WATER HAMMER

This fault is not uncommon and should be observed and corrected by the installer at the time of installation. The Installation Report requires that the installer check the installation prior to handing the system over to the customer.

If water hammer does exist the following points should be checked:

WATER DISCHARGE FROM THE PRESSURE & TEMPERATURE RELIEF VALVE

Water should not be released automatically from the Pressure & Temperature Relief valve unless the hot water temperature is at 99C or the pressure is greater than 700 kPa. If water is being discharged from the valve the following checks should be made:

WATER DISCHARGE FROM THE COLD RELIEF VALVE OF THE COMBINATION INLET VALVE

The Cold Relief Valve is designed to release water from the system should the pressure rise above 600 kPa. Water discharge from the cold relief valve is normal when the potable water is being heated. A volume between 5 and 30 litres a day is quite common. If the discharge is greater than this volume the valve operation should be checked as follows:

INSUFFICIENT PRESSURE

The Pressure Control Valve of the Combination Inlet Valve is designed to limit the maximum supply water pressure to 450 kPa at a flow rate of up 30 litres per minute. If the pressure at the solar hot water system is less than 450 kPa and the flow rate is less than 30 litres per minute the following checks should be made:

HYDROGEN GAS IN STORAGE TANK

The production of small quantities of hydrogen gas is common in anode protected, enamel lined, steel hot water storage cylinders. This occurs mainly when the stored water is not used for an extended period of time. Occasionally larger than normal amounts of gas can be present, this is usually the result of a combination of hard water quality and an anode slightly out of specification. Installations where the potable water TDS level is greater than 1,000 ppm should be accessed for conversion to an aluminium anode. If the TDS level is lower than 1,000 ppm the existing anode should be replaced as a preventative measure to future gas discharge.

ELECTRICAL BOOSTER SWITCHED "ON" WITH AN EMPTY TANK

The electrical elements are designed to use the water to maintain the sheath temperature at below 130C, if the element is turned on without the cylinder being full of water the element sheath temperature will continue to rise until severe distortion causes electrical failure. If this has occurred replace the electric element even though it may not seem to be electrically damaged. The copper sheath will have been weakened and the element distorted. It is also important to check the hot water scoop inside the tank to ensure it has not been distorted from the excessive heat generated by the element. If damaged or distorted it must be replaced ensuring that it is installed with the open end facing the top of the cylinder. Similarly check the cold water stratifier for damage and replace if necessary.

THERMOSTAT SAFETY CUT-OUT ACTIVATED

The thermostat safety cut out is designed to disconnect the booster device from the supply if the temperature of the potable water rises above 87C when the booster is operating. The potable water temperature can, however, regularly reach in excess of 87C from solar collection when low usage rates are experienced, under these conditions the safety device will automatically reset when the temperature falls to below 72C. If the high temperature is the result of booster operation the safety device will trip and can not be reset. When this occurs the thermostat is not repairable and must be replaced with the Robertshaw SA203 thermostat.

GENERAL CONDITION REPORT

Whenever a system is visited for service a general condition inspection should be conducted covering such items as:


CLOSED CIRCUIT SERVICE PRECAUTIONS

IMPORTANT


FIVE YEARLY SERVICE PLAN

CLOSED CIRCUIT INSPECTION

a) Conduct a visual inspection of all joints and seals for signs of closed circuit leakage at each of the following locations:

If there are no visual signs of leakage proceed to step (b) below.

If visual signs of leakage are present at any of these points, all seals should be removed. The tank and collectors must separated and pressure tested in accordance with the procedure detailed in (c) below, before fitting new seals and recharging the system as detailed in (d) below.

b) Test the fluid level in the closed circuit as follows:

c) If the fluid level is below this 60 mm band the closed circuit has a leakage which must be located and corrected prior to continuing the service.

Location of the leakage should be found using the Commissioning and Service Kit described in Section 10

TESTING THE TANK

TESTING THE COLLECTORS

d) Having located and replaced the leaking component all seals should be replaced and the system should be reassembled and commissioned as detailed in Technical Bulletin 97.

During this procedure the reclaimed closed circuit fluid may be returned to the closed circuit and supplemented with a solution of 20% Hartgard and water to completely fill the closed circuit.

REPLACE THE SACRIFICIAL ANODE

The anode should be replaced using the following procedure:

REPLACE THE PRESSURE AND TEMPERATURE RELIEF VALVE

The hot water relief valve should be replaced using the following procedure:

CHECK THE ELEMENT AND THERMOSTAT OPERATION

The element and thermostat should be checked using the following procedure:

INSPECT AND FLUSH THE COLD WATER COMBINATION VALVE ASSEMBLY

CLEAN THE COLLECTOR GLASS AND TANK BODY

HARD WATER AREAS


FAULT FINDING FD15-12 GAS BOOSTER

The FD15-12 Gas booster supersedes the FD15. The major differences are:

The operation is fully automatic as it progresses through the start cycle following the sequence :

If any of these functions are not performed correctly the unit will switch to either a primary or secondary lockout dependant on the number of times it has tried to restart. When a primary lock-out occurs the unit will reset itself and perform the start up cycle for a second time. If at the second attempt the unit fails to establish the flame, the unit will shut down in secondary lockout and remain in this mode until the power to the unit is turned off.

The indicator light on the thermostat will flashing when a primary lock out has occurred, and stay on at full brilliance when a secondary lock out has occurred.

The controller will go straight to secondary lock-out if the controller itself is faulty, the fan is outside the specification or when an over temperature occurs in the tank due to thermostat failure.

The following section will give you a step by step guide to determine the cause of the incorrect functions of the gas booster.

Detach the flue terminal from the base plate to expose the electronic control box.

To test the system operation insert a temporary barrier (cut from cardboard or thin metal) in the burner cone between the burner cone baffle plate and the fan mounting plate. This will ensure that exhaust gasses are not drawn into the burner by the fan. When exhaust gasses are mixed with the fresh air intake the flame sensing device will be disturbed and the unit will lock out.

Switch the unit "on" allowing it to move through the start up cycle, be aware that it will take about 25 seconds before the fan starts to run. The burner tube is purged for a further 25 seconds before the solenoid valve opens and the 5 second sparking period ignites the burner. Watch every step closely to determine at which step the controller locks out.

If the unit has been converted to LPG check the burner nozzle for the correct size and that the spring in the gas regulator has been replaced by the spacer pin.

If the unit has been converted to TLP check the burner nozzle for the correct size and that the copper connection tube between solenoid and burner has been replaced with the larger ( 8 mm) diameter tube.

FAILURE STEP 1

If the unit does not start at all conduct the following checks:

FAILURE STEP 2

Fan starts up but then immediately locks out. - Replace the fan and retest. Should the new fan fail replacement of the electronic control box will be necessary.

FAILURE STEP 3

Sparker does not operate conduct the following checks:

FAILURE STEP 4

If the sparker fires for 5 seconds but burner does not operate conduct the following checks:

FAILURE STEP 5

Should the burner ignite but fail in a short period of time conduct the following checks:

SOOT BUILD UP IN THE FIRE TUBE

Soot built up is generally caused by incomplete combustion burning due to low oxygen levels or high supply pressures.

The following items should be checked to identify the cause:

A new style baffle plate is available with a V-shape stiffening rib formed along the centre of the baffle plate, these baffle plates locate more securely into position.


FAULT FINDING FD15 GAS BOOSTER (DISCONTINUED)

The following section will give you a step by step guide to determine the cause of the incorrect functions of the gas booster.

LOCK OUT

Should the electronic controller that monitors the function of the gas unit detect an error in the operation it will shut down all functions until the fault has been addressed, this is commonly known as a LOCK OUT. Lock-out will occur should any one off the following faults occur :

To reset the controller when a lock out has occurred the power supply should be switched off for 10 seconds. If the Gas Booster continues to lock out, the following procedure can be used to determine the cause.

WARNING: CAUTION SHOULD BE TAKEN WHEN WORKING ON THE GAS BOOSTER. THERE IS A 240 VOLT ELECTRICAL SUPPLY CONNECTED TO THE THERMOSTAT. THE HOUSEHOLD POWER SUPPLY MUST BE ISOLATED BEFORE INTERNAL SERVICE WORK, OTHER THAN FLUE TERMINAL REMOVAL, IS PERFORMED.

Detach the flue terminal from the base plate to expose the electronic control box.

To test the system operation insert a temporary barrier (cut from cardboard or thin metal) in the burner cone between the burner cone baffle plate and the fan mounting plate. This will ensure that exhaust gasses are not drawn into the burner by the fan. When exhaust gasses are mixed with the fresh air intake the flame sensing device will be disturbed and the unit will lock out.

The blue control box is equipped with 5 indicator lights (Right Hand side bottom corner) which represent the following conditions :

  1. Fan running
  2. Ignition/ timer fail
  3. Flame fail
  4. Ignition fail
  5. Fan fail

LIGHT 1 "ON"

Fan is running, purging the fire tube of any un-burned gasses.

LIGHT 2 "ON"

The built-in timing device for the 5 second sparking duration has failed. - Replace blue control box.

LIGHT 3 "ON"

The burner failed to stay "on" after it has being ignited.

LIGHT 4 "ON"

Burner failed to ignite check the following :

Re-wiring early model units so the 240 V supply is connected to the thermostat rather than having a 24 volt connection to the thermostat reduces voltage spikes to the controller. Voltage spikes in the 24 volt supply can cause false lock out conditions. The preferred method is to pass the 240 volt supply through the thermostat to a three pin outlet located within the roof space. The 24 volt transformer should be plugged into this outlet and the 24 volt supply wires connected directly to terminals 2 & 4 on the blue box controller.

Ensure that all the connections have been made before the power to the transformer is turned on. Short circuiting the transformer's supply wires will damage the transformer.

LIGHT 5 "ON"

Indicates fan failure or incorrect running speed check the following details:

SOOT BUILD UP IN THE FIRE TUBE

Soot build up is generally caused by incomplete combustion due to low oxygen levels or high supply pressures. The following items should be checked to identify the cause.

A new style baffle plate is available with a V-shape stiffening rib formed along the centre of the baffle plate, these baffle plates locate more securely into position.