Alpha Boilers Troubleshooting



Boilers have become an integral technique in almost every home. The breakdown of this technique can make difficulties to its owner. Below there are 8 tables that will be the must-have manual for the owner of Alpha Boilers. They include different error codes that can give the boiler and the ways in which the owner easily repairs the boiler yourself.

Alpha SY9-24 Boilers Troubleshooting

Error codeMeaningSolution
Code 71Collector sensor faultTemperature of the collector is below -40*C or above 250°C.
Check the collector sensor does it operate
Sensor cable damaged or short circuited.
Sensor is faulty.
Code 72Upper cylinder sensor faultTemperature of the cylinder is below 0°C or above 100*C.
Check the upper cylinder sensor: does it operate
Sensor cable damaged or short circuited.
Sensor is faulty.
Code 74No circulation in the collectorCheck water level in drain back unit.
Check the difference in height between the drain back unit pump and the upper most side of the collector. This can be a maximum of 3 metres.
Check the collector sensor and the lower cylinder sensor, do they operate
Check the collector tubes, are they blocked with dirt? Is the decline of the pipes within the 40 mm per metre requirement.
Check the electrical connection and operation of the drain back unit pump and the cylinder pump.
Code 75Collector temperature too highAfter 5 minutes the collector temperature is still too high (above 130°C) with the drain back unit pump operating.
Check the level of water in the drain back unit.
Check the difference in height between the drain back unit pump and the upper most side of the collector. This can be a maximum of 3 metres.
Check the collector sensor and the lower cylinder sensor, do they operate
Check the collector tubes, are they blocked with dirt? Is the decline of the pipes within the 40 mm per metre requirement.
Check the electrical connection and operation of the drain back unit pump and the cylinder pump.
Code 77The system is not turned onThe control has not been operating for 30 days.
Check the collector sensor and the lower cylinder sensor, do they operate
Code 80Lower cylinder sensor faultTemperature of the cylinder is below 0°C or above 100*C.
Check the lower cylinder sensor: does it operate
Sensor cable damaged or short circuited.
Sensor is faulty.

Alpha AL357I-B Boilers Troubleshooting

ProblemCauseSolution
Chimney fireIf your stove has been installed correctly and you have also operated it correctly and regularly carried out the recommended routine checks then it is unlikely that you will ever experience a chimney fire, which can be highly dangerous.Chimney fires can be detected by an unusual roaring sound and / or unusual vibrations coming from the chimney breast or the stove itself. The sound is not to be confused with the gentle ‘rushing’ sound you may normally hear when a stove has a well performing up-draught. During a chimney fire you may also see sparks or flames exiting from the chimney terminal outside
Prevention If you suspect a chimney fire then immediately close the Primary and Secondary Air controls, as well as the Thermostat Control, evacuate the building and call the Fire Service. Never open the stove door as this will make the chimney fire worse by providing additional combustion air. Do not re-enter the building until you have been advised by the Fire Service that it is safe. Do not re-light the stove until the flue system has been thoroughly inspected by an approved installer or chimney sweep and any necessary repairs have been carried out
Inadequate cleaningChimney fires occur when soot and creosote have built up to such a level that they ignite. It is important therefore that your flue system has as many cleaning access points as practicable to enable comprehensive removal of soot, creosote and other debris. This will also minimise the amount of time it takes for a qualified sweep to clean the system making the system safer and its cleaning more cost-effective in the long run
Continuous low burningTo discourage the potential for such soot and creosote build-ups, long periods of consistent ‘slumber’ or overnight burning should be avoided or that these should at least be compensated for by regular burning on full output for short periods (eg 30 minutes per day) to help burn off any likely deposits before they become problematic
Poor fuel choiceAs previously mentioned unseasoned or damp wood or fuel should always be avoided as these produce excessive soot and creosote. This is particularly problematic for boiler stoves where the fire chamber temperatures are much lower than in a non-boiler stove and therefore the potential to promote the conditions for dangerous deposits from damp fuel is much greater
Stove, flue or other components glowing redThe Primary and Secondary Air controls, as well as the Thermostat Control, should be immediately closed to let the fire die down to an acceptable level and to reduce the heat output which will in turn eliminate the glow from the over-heated components. At the same time ensure that water within the system is not ‘boiling’. Your central heating system should have the requisite safety valves to prevent this, but if in doubt run off excess hot water and ensure the central heating pump is working to dissipate the excess heat and hot water. Over-firing is dangerous and could permanently damage or warp your boiler stove and its components. The effects of over-firing are fairly obvious to anyone in the stove industry and will invalidate your Alpha Warranty. Check the stove, the flue system and the central heating for any signs of damage or system failure before you re-use the stove
Over-FiringThis is caused by using the stove at a higher output than recommended for prolonged periods of time and / or over-filling the firebox with fuel. The excessive heat in the flue system produced by over-firing could potentially also lead to a chimney fire
Smoke and fumes escaping into the roomWhen properly installed and operated your stove should not normally emit fumes or smoke into the room. When first using the stove it is normal to experience paint fumes or see light smoke rising from some of the stove’s painted surfaces, but these should eventually pass as the paint cures. Occasional minor smoke escape may also occur during the refuelling process. However, persistent smoke or fumes could be dangerous and in this situation you should take immediate avoiding action.
Prevention: Open doors and windows to ventilate the room and let the fire go out to allow the stove to cool. Never pour water onto the fire as this could cause the cast iron components to break.
Most importantly, never re-light the stove until the problem has been identified and solved. If in doubt, in the first instance always seek the expert advice of your approved installer, or authorised Alpha dealer.
There are a number of factors, either alone or combined, which could cause such problems
A blockageWhen safe to do so, examine the flue-way above the baffle plate as well as the chimney system via any inspection hatches and clear any soot blockages. Excessive deposits could also indicate that the chimney or flue itself also needs cleaning
Inadequate supply of combustion airCheck that any permanent air vent fitted to supply the extra combustion air required for the stove has not been accidentally blocked. Remember there should never be an extractor fan in the same room as a stove. A simple way of checking whether or not the stove is receiving enough combustion air is to open a window in the same room as the stove whilst the stove is operating. If this improves the problem then this would certainly indicate that the stove is being starved of combustion air and the advice of the original installer should be sought
Extreme weather conditionsHigh winds or extremes of temperature can also temporarily affect the performance of the chimney draught and consequently its effectiveness in removing smoke and fumes from the stove’s fire chamber. In the case of freezing temperatures it is important to build a larger pre-fire than normal to quickly provide the additional heat needed to warm the flue system and to counteract the much lower temperatures at the exit point of the chimney. This is particularly important for boiler stoves which have the disadvantage of the fire chamber being surrounded by very cold water. Unusually hot sunny days in the Autumn can sometimes produce negative pressure which will affect the up-draught and in these instances you should open a window or door to the outside to help re-balance the interior and exterior pressures which create the up-draught mechanism. Once you are con- fident that the up-draught has re-started you can then close any doors or windows
High windsIf the problem is associated with high winds and it becomes a regular occurrence, then you will need to fit a specialist chimney cowl. These are designed to provide a stable draught and prevent specific types of problems. Specifying the right cowl should always be left to an approved installer
Flue ExitCheck, especially at the beginning of the heating season, that summer tree growth has not interfered with the free passage of smoke and flue gases from the chimney top
Overheating and excessive fuel consumptionExcessive Chimney DraughtThis limits the effectiveness of the air controls so that the fire burns with very strong bright yellow flames and with very little difference when the air controls are operated. In such circumstances, and where possible, an adjustable draught stabiliser in the flue system may need to be fitted to ensure that the stove will always operate under a stable draught to allow the stove’s controls to function correctly. In the interests of safety, because draught stabilisers limit the exit of flue gases from the stove, they should only ever be specified, fitted and subsequently tested by an approved installer
FuelThe fuel itself may be of poor quality. For example pine and other softwoods used in the building trade will burn much quicker than a good hard wood log, such as Oak
Faulty Door SealsThe rope seals around the fire chamber door could have become worn and may not create the air-tight seal needed for the Primary and Secondary Air controls to function correctly. When the stove is cold, you can easily check this seal by placing strips of paper at various points between the door and chamber and checking that when the door is closed it grips this paper. Any paper which can be removed easily would indicate a weakness of the door seal in that particular spot, in which case a complete new rope seal should be fitted
Stove not providing enough heatThis problem is also usually indicated by dull orange lifeless flames and wood that remains black when burning instead of light grey
Poor fuelPoor heat output is more than likely caused by poor fuel, such as ‘green’ or unseasoned wood or even wet wood. We cannot over-estimate how critical it is to use fully seasoned dry wood in a boiler stove. The easiest way to check whether your wood is fully seasoned is to invest in a moisture meter specifically designed for testing wood fuel. These are relatively inexpensive and can be purchased from your stove dealer. When you bear in mind that seasoned wood with a moisture content of less than 20% will give you approximately 50% more heat than unseasoned wood, a moisture meter is a modest investment which will more than pay for itself
BlockagesWhen safe to do so, examine the flue-way above the baffle plate as well as the flue liner or chimney system, either through the stove or via any inspection hatches. Clear any soot blockages. Excessive deposits could also indicate a poor choice of fuel or that the chimney or flue itself also needs cleaning more often than previously thought
Circulation PumpThis may need re-adjusting to slow down the system’s flow because it does not provide the water with a slow enough passage through the stove’s boiler to heat up the water sufficiently. This in turn prevents the fire chamber from ever reaching a good operating temperature. It could also be that the central heating system may need to re-balanced at the same time.
Glass staining or blackeningGlass can be cleaned easily if it is undertaken regularly and the deposits are not allowed to build up. A proprietary stove glass spray or gel is strongly recommended
Air ControlsEnsure that you fully understand how the Airwash system works and that you have determined, through some trial and error that you have the correct balance between the Primary, Secondary and Thermostat Controls that your stove needs. Generally, try to use more Secondary Air when burning wood as this air flows down and over the glass to help burn and wash away any particulates that have accumulated there
Poor fuelBurning damp or unseasoned wood will cause the glass to stain as the moisture from the fuel considerably reduces the fire chamber temperature reducing the effectiveness of the Airwash system. ‘Green’ wood will also encourage sticky deposits on the glass which will prove difficult for the impaired Airwash system to remove
Condensation in the fire chamberYou may see moisture droplets on parts of the boiler or experience damp ash when the stove is cold or after the stove has been used
Atmospheric conditions It is not unusual for condensation to form on a cooling boiler or pipework under certain atmospheric conditionsSuch condensation should not be confused with a boiler leak. In the unlikely event of a boiler leak a profuse amount of water, which is usually hard to stem, will occur. This is significantly different from condensation which can be easily dried out with a sponge or tissue or by re-lighting the stove. After the fire has gone out, open all the air controls and leave the stove door slightly open, as this can sometimes help.
Central heating system not providing enough heat or hot waterIf you have ensured that the stove is functioning properly ie that it has vibrant yellow flames and is providing heat to the room, but still not delivering sufficient heat through the central heating radiators or hot water then it is more than likely to be a problem with the system. The simplest way to determine this is, if possible, to check that the top water pipe from the stove is hot and that the lower pipe is cooler. If this is the case then this indicates that there is a problem with the system and not the stove
Circulation pump or thermostatic valve failureA fault in one of the system’s key components could restrict the system flow thus limiting heat to the radiators and / or hot water cylinder. For example, a thermostatic valve may have been activated due to a potential temperature anomaly or have stuck in the wrong position. Identifying the precise problem is a job best left to the original installer or heating engineer

Alpha CD50S Boilers Troubleshooting

CodeDescriptionSolution
0Flame sensor fault detectedCheck flame sensing electrode and wiring Check PCB
2Ignition failureCheck gas supply
Check electrode position
Check flame sensing signal is greater than 6^A
3Gas valve supply errorCheck gas supply
05 06 11 13 14 15 16 17 44 60Internal fault (electronics)Check electrical connections Check PCB
4Burner lock-out (electrical fault)Check electrical connections
7Gas valve relay fault
12Overheat safety thermostat operatedCheck PCB fuses
Check primary flow thermostat
Check flue thermostat
18Primary flow temperature too highCheck water circulation Check for air in the system
19Primary return temperature too high
24Return temp, higher than flow temp, by more than 10*C after 180 sec
25Rapid primary flow temperature increase
26Insufficient water pressureCheck for system leaks Repressurise the system 0.75 – 1.25 bar
28Fan fault (no Hall signal)Check fan Check fuse F3
29Fan faultCheck fan Check fuse F3 Check electrical connections Check PCB
30Temperature difference between system flow and return too highCheck water circulation Check for air in the system

Alpha Solarsmart 90 Boilers Troubleshooting

DisplayItem being diagnosed
SOSoftware version
DOFrost protection
D1Mode
D2Collector temperature
D3Upper cylinder temperature
D4Not allocated
D5Lower cylinder temperature
D6Not allocated
D7Drain back unit pump speed
D8Cylinder pump speed
D9Not allocated
E0- E9

Alpha 26C Boilers Troubleshooting

Error codeFaultFault descriptionPossible causes
E01Ignition failureFlame not detected during ignition sequenceGas supply Check pressure tubes Ignition electrode gap Flame sensor electrode gap Ignition generator or lead Flame sensor electrode lead Gas valve setting Gas valve PCB
E02Overheat boiler lock outOverheat thermostat or thermal fuse has operatedPump or flow problem
Blocked heat exchanger
Air in heat exchanger
Overheat thermostat
Thermal fuse (if open circuit then replace primary heat exchanger)
E03High flue thermostat temperatureRue thermostat intervention (flue temperature over 113°C)Blocked or restricted primary flow Heat exchanger air flow blocked Flue restriction Flue sensor fault
E04Gas valve electrical connection faultGas wiring circuit fault detectedGas valve lead connection fault Faulty gas valve Faulty PCB
E05Heating flow sensor faultIncorrect flow sensor resistance valueFlow sensor wire connections Flow sensor faulty
E06DHW sensor fault (InTec C, X. GS only)DHW sensor resistance value is incorrectDHW sensor wiring connection DHW sensor faulty
E08Maximum number of resetsMaximum number of resets reached
E10Primary system pressure lowPrimary pressure switch has operatedCheck expansion vessel pressure (1 bar) Leak in system
Expansion relief valve operated Primary pressure switch
E12Cylinder sensor fault (InTec S and FlowSmart only)Incorrect cylinder sensor resistanceCylinder sensor wiring connections Cylinder sensor faulty
E15Internal wiring errorIncorrect wiring configuration detectedCheck internal wiring connections to PCB Combination boiler DHW sensor X4 System boiler link X14
E16Fan faultFan wiring fault or fan faultyCheck fan wiring connections Fan fault PCB fault
E20Flame sensing faultFalse flame detection Flame detected but gas valve is not openCheck flame sensing electrode and lead PCB fault
E24Control panel button faultControl panel button stuck in the on positionCheck for jammed control panel buttons Check for jammed PCB buttons
E25Overheat lock outRapid temperature rise of flue sensorAir in heat exchanger
Blocked or restricted primary flow
Heat exchanger air flow blocked
Rue restriction
Rue sensor fault
Pump fault
Boiler or heating circuit valve closed
E27Insufficient primary flowRapid temperature rise of primary sensorBlocked or restricted primary flow Air in heat exchanger Boiler or heating circuit valve closed Pump fault
Primary flow sensor fault
E29Flue sensor faultFlue sensor resistance out of rangeCheck sensor wiring connection Rue sensor faulty
E31Loss of communication with external control (Alpha Climatic)Loss of connection between the boiler and Alpha Climatic control unitRemote control or receiver connection wiring Remote control or receiver
E37Low supply voltageInsufficient supply voltage to operate boilerCheck mains power suppty
E38Loss of flame rectificationFlame detected but signal is lost. Ignition reattempts after fan purgeCheck flame sensing electrode and lead Check for flue gas recirculation Check/adjust the gas valve settings Check/adjust the fan speed settings
E43Loss of flame rectificationRepeated loss of flame signal during operation (shown as E38 in the fault code history in the INFO menu)Check gas supply/working pressure Check flame sensing electrode and lead Check for flue gas recirculation Check/adjust the gas settings Check/adjust the fan speed settings
E44Safety lock outThe boiler has attempted to fire repeatedly for the maximum time limitCheck external control (room thermostat) requests
Rapid on/off hot tap requests
E46External sensor interventionNo continuity of external sensor circuitCheck external sensor and cable are not damaged or wet
Check continuity of external sensor and circuit Check connection at XI9 on PCB and sensor connecting block
E47Reduced burner outputFlue thermostat has sensed high flue gas temperature (110°C) and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lock out and E03 will be displayedAir in heat exchanger Restricted primary flow Heat exchanger air flow blocked Rue restriction Rue sensor fault Pump fault

Alpha InTec 12S (NG) Boilers Troubleshooting

Fault codeFault descriptionPossible solutions
FE90PCB compatability faultCheck PCB is connected correctly. Check for water ingress in connections.
FE94Display PCB fault.Check electrical connections to display board. Check for water ingress in connections.
Check for damage to buttons or LCD screen.
FE95Flow sensor out of range or short circuit.Check flow sensor connections and damaged wires. Check flow sensor resistance values
Flow sensor measures a temperature outside normal working range
FE96External sensor fault.Check external sensor connections and wires. Check for water ingress in connections.
Check boiler parameter settings are correct.
FE97Boiler PCB configuration error.Check all electrical connections
Check for correct parameter settings on PCB
FE99PCB communication error.Check all electrical connections
Fault detected in the link between the main PCB and the displayCheck for correct parameter settings on PCB

Alpha Pro Tec 50 Boilers Troubleshooting

Fault code OEFault descriptionPossible solutions
01Flame sensing fault.Check flame sensing electrode connections. Check for a short circuit to the electrode or wire.
02Flame circuit fault.Check for correct gas supply (purged and valves open). Check ignition electrode position and spark.
Check flame sensing electrode gap and connections.
03Main PCB fault.Check all electrical connections.
Check for water ingress in connections.
04Main PCB fault.Check all electrical connections.
Check for water ingress in connections.
05DHW sensor short circuit.Check DHW sensor connections and wires. Check for water ingress in connections.
06DHW sensor out of range. DHW sensor measures a temperature outside normal working range.Check DHW sensor connections and damaged cables. Check DHW sensor resistance values.
07Low powers supply voltage.Check electrical socket connections. Check external power supply.
08Insufficient system flow – (Pro Tec 50 model only). Insufficient system pressure – (Pro Tec 70, 90, 115 models).Check the system for circulation and restrictions. Check system pressure and gauge.
Check boiler flow meter and connections (Pro Tec 50).
09Flue sensor short circuit.Check flue sensor connections and wires. Check for water ingress in connections.
10Flue sensor out of range.Check flue sensor connections and wires. Check flue sensor resistance values.
Flue sensor measures a temperature outside normal working range.
12Flow and return sensor anomily detected.Check for poor or incorrect circulation.
The sensor shows an incorrect temperature value.Check for external circuit influences.
Check resistances of flow and return sensors.

Alpha Pro tec 70 Boilers Troubleshooting

Fault code OAFault descriptionPossible solutions
OA1Ignition failure.Check for correct gas supply (purged and valves open). Check ignition electrode position and spark.
Check flame sensing electrode connections.
Check gas valve operation.
OA2Overheat thermostat or thermal fuse has operated.Check flame sensing electrode connections.
Check for a short circuit to the electrode or wires.
Reset overheat thermostat if required.
OA3Overheat thermostat lock-out.Check for water circulation.
Check for air in the heat exchanger.
Check for system restrictions and blockages.
Check overheat thermostat and connections.
Reset overheat thermostat if required
OA5Fan speed fault.Check flue and ventilation.
Check air inlet manifold and pipe.
Check for fan damage/fault.
Check fan wire connections.
OA7High flue temperature fault.Check for air in the primary heat exchanger.
Check for system restrictions causing overheating.
Check the flue run for restrictions or blockages.
OA9Gas valve electrical error.Check gas valve connections. Check main PCB.
Check gas valve operation. Check for gas contamination.
OA13Maximum number of resets reached. More than five reset attempts have been reached within 15 minutes.Investigate initial fault code displayed.
Switch the power supply Off/On to clear this code.
OA15Flow and return sensor anomily detected. The sensor shows an incorrect temperature value.Check for poor or incorrect circulation.
Check for external circuit influences.
Check resistances of flow and return sensors.
OA16Flow sensor temperature rise incorrect. The time taken for the flow temperature to rise is too great.Check system circulation.
System volume or flow is too high.
The boiler output is insufficient for the system.
OA17Return sensor temperature rise incorrect. The time taken for the return temperature to rise is too great.Check system circulation.
System volume or flow is too high.
The boiler output is insufficient for the system.
OA18Flow and return sensor anomily detected. Sudden temperature change detected on the flow or return sensor.Check system circulation.
Check operation of zone valves.
Check resistances and function of flow and return sensors.
OA30Flow sensor short circuit.Check flow sensor connections and wires.
Check for water ingress in connections.
OA31Flow sensor out of range. Sensor measures a temperature outside normal working range.Check flow sensor connections and damaged wires.
Check sensor resistance values.
OA37Insufficient system flowCheck the system for circulation and restrictions.
Check the boiler flow meter connections.
OA43Return sensor short circuit.Check return sensor connections and wires.
Check for water ingress in connections.
OA44Return sensor out of range. Sensor measures a temperature outside normal working range.Check return sensor connections and damaged wires.
Check return sensor resistance values.
OA80Flow and return sensor connection fault. Fault may occur after several minutes of boiler operation.Check the wires are connected to the correct sensors.