Grant Combi Boiler Error Codes
Grant Combi Boiler Error Codes

Grant Combi Boiler Error Codes

Grant Combi Boiler Error Codes When there are problems with your boiler, it can be a frustrating time. So, in this guide, we provide the information you need to work out what the problem may be. If your home is installed with a Grant boiler, we’ll be taking you through some of the most common problems you might come across and how to get the boiler going again. Should you be in any doubt at all about what’s wrong with your boiler, use our free service to get quotes from reliable engineers near you.

Grant Boiler Error Code Solutions

Grant Boiler Error Codes
Fault CodeCause of Problem
No display12V transformer failure
PP1Inlet (return) water temperature sensor failure
PP1Inlet (return) water temperature sensor failure
PP2Discharge gas sensor failure
PP3Coil temperature sensor failure
PP4Return gas sensor failure
PP5Ambient temperature sensor failure
PP6Discharge gas overheat protection
PP7Winter anti-freeze protection in operation
EE1High pressure – circulating pump failure or circuit air locked
EE2Low pressure
EE3Open circuit between PCB terminals 23-24
EE4Supply L and N are reversed
EE8Communication failure
Flashing on and offDefrosting
E01Internal control fault
sHrHP flow sensor short / HP return sensor short
OPnHP flow sensor open / HP return sensor open
SUPSupply sensor short / Supply sensor open
OUTDROutdoor sensor short / Outdoor sensor open
C2849Fault C; Chassis Code
Problem is controller area network wiring bus and modules.
fault two; MFG – Manufacturer Specific
Fault eight; Ignition System Or Misfire
fault four; BBV Sensor Circuit Low Voltage
fault nine; Kick-Down Switch Failed Short
U2453Fault U: Network Code
Problem is climate control system, lighting, airbags, etc..
fault two; MFG – Manufacturer Specific
fault four; Transmission
fault five; TP Sensor Learn Not Complete
fault three; Transmission Control Module Reprogrammable Memory

Grant Boiler Error Description

Grant FaultFault Description
Boiler Will Not StartLow pressure cut-out activated No electrical supply to burner Check
controls are switched on and calling for heat Boiler thermostat and/or
overheat thermostat faulty
Burner lights but goes to lock-outFault with burner No fuel supply Oil tank empty Fire valve closed Fire valve
closed. Fuel line filter is blocked Oil supply line is air locked Excessive
combustion air Fault with burner
Burner fires but smoke visible from flue or high
smoke number
Insufficient combustion air supply to burner Incorrect or faulty nozzle fitted
Fuel pressure too high
Burner pulsatesInsufficient combustion air supply to burner
Burner cycles On and OffContaminated combustion air (balanced flue) Insufficient oil flow to burner
due to restriction in supply line Excessive combustion air
Fumes and puffing on startingFlue is blocked Insufficient flue draught Flue pipe or liner is too large or
existing stack is unlined Insufficient combustion air supply to burner
Flame slow to stabilise on startingInsufficient combustion air supply to burner Fuel pressure too low
Oil smellsOil leak in supply line or burner
Combustion fume smellsLeak around boiler cleaning door Burner not correctly fitted on mounting
flange Burner seal ‘O’ ring damaged or missing. Leakage around flue
Overheat thermostat operatingFaulty boiler thermostat Thermostat sensor not connected to printed circuit
board (PCB) – Vortex Combi only Faulty overheat thermostat
No water flowing from hot tapMains water supply is not connected to cold water inlet of boiler One or
more isolating valves, stop cocks, etc. in the pipework are closed The cold
water isolating valve in the boiler is closed There is a blockage
(or blockages) in the pipework
No hot water operationHot tap is not connected to hot water outlet of boiler Insufficient flow of
water through boiler Boiler cold water and hot water connections reversed
Thermostatic mixing valve incorrectly fitted Pump is not operating in hot
water mode Diverter valve microswitch(es) faulty Diverter valve
microswitches not operated Diverter valve seized Diverter valve diaphragm
Low water temperature at tapFlow of water through boiler too high Boiler thermostat incorrectly set
Thermostatic mixing valve incorrectly set Faulty boiler thermostat Pump
speed setting too low Pump is incorrectly fitted
Hot water for short period onlyBurner not firing for hot water (after a short time) Burner oil pressure set
too low at oil pump Incorrect oil nozzle fitted to burner
No operation on heatingTimeswitch either not set, or not in an ‘ON’ period Timeswitch not operating
Faulty timeswitch Faulty timeswitch switch contacts Timeswitch OK but not
switching boiler on Heating switch set to ‘HOT WATER ONLY’ Room
thermostat not calling for heat Faulty room thermostat No room thermostat
or external timeswitch connected to boiler
Flow temperature lowBoiler thermostat is set too low Boiler thermostat faulty Boiler is underfired
Combustion setting of burner incorrect Boiler heat exchanger is sooted up
Grant Vortex / Eco / Pro Boiler Error Codes
Fault CodeCause of Problem
No fuel supplyInsure that an adequate supply of fuel is available and that the fuel supply
valve is open – check the condition of the fuel filter and clean if necessary,
ensure fuel supply is reaching burner and vent pump
No Electricity SupplyEnsure electricity supply to the boiler is switched on and that all controls
are calling for heat – ensure that the overheat thermostat has not tripped,
reset if necessary and check the mains supply
Burner not starting – fuel and electricity supplies
Reset boiler on the burner control box – if it is lit refer to burner fault finding
Burner lights but goes to lock outIf the flame is unstable check the combustion setting
Visible smoke from flue or high smoke numberInsufficient air supply. Check the air damper setting and the condition of
the fan check room ventilation, check the nozzle size and type, fuel pressure
may be too high, check and adjust
Burner pulsesInsufficient air supply – check the air damper setting and the condition of
the fan, check room ventilation
Flame slow to stabilise during start upInsufficient air supply – Check the nozzle size and type as fuel pressure may
be too low, check and adjust insufficient draught clean boiler heat
exchanger and check condition of flue
Water temperature lowUndersize nozzle and or low fuel pressure check condition of boiler heat
exchanger and clean if necessary. Check the boiler thermostat, check the
combustion setting, check the condition of the fuel filter
Boiler operating an overheat thermostatFaulty boiler thermostat – no circulation, check circulating pump, check for
air lock
Fumes and puffing during startingCheck the condition of the chimney to ensure it is not blocked and is high
enough to produce the required draught – check that there is an adequate
air supply near the burner fan is not drawing products out of the burner
Oil odoursCheck all fuel line connections and remake as necessary
Combustion fumes smellCheck boiler cleaning cover and seal are correctly fitted, check burner is
correctly fitted onto flange, check flue is correctly sealed into flue outlet of
boiler, check the condensate pipe and trap are operating correctly

Grant Vortex Blue Error Codes

Fault CodeCause of Problem
Red blinking lightPresence of a false flame signal before heat request
Red blinking lightPresence of false flame signal during pre-purging
Red blinking lightPresence of false flame signal during post-purging or pre-heating
Red steady onUV sensor defective or dirty oil valve defective fault – ignition transformer
badly regulated burner, oil fuel not present
Red blinking lightBadly adjusted burner, oil valve defective or dirty UV sensor defective or dirty
Red and orange blinking invertedError with oil valve internal control circuit that drives the oil valve error
Red green blinking invertedInternal memory error
Orange green blinking invertedCheck presence of voltage, check the condition of the fuses, check that safety
thermostat is not in lockout
OffEliminate the extraneous light
OffCheck that plugs and sockets are connected properly
Red blinking lightEliminate the extraneous light
Red steady onClear it / replace it / check the pressure and output of the fuel / check air
output change nozzle check the coil od solenoid valve
Green blinking lightSet the air according to the instructions of the manual or replace

Grant Vortex Eco Error Codes

Fault CodeCause of Problem
Motor fails to runNo electrical supply to boiler check on/off switch is on – it should be neon lit
Lock-out light not litFuse has blown – check reason for failure
Motor fails to runNo power to burner motor
Burner lock outBurner motor capacitor fault check and replace if necessary

Grant Vortex Pro Combi Error Codes

Fault CodeCause of Problem
Power supplyCheck that fused spur for heating system and boiler is switched on – check
that the electricity supply has not failed
Heating system controlsCheck that the timer or programmer is working and set to an on period
Boiler controlsCheck boiler on/off switch is set to on – check that power indicator on and
control panel is lit
BurnerCheck the burner lockout reset button is lit, if yes press the reset button to
start the burner if burner fails call an engineer
Heating systemCheck the heating system water pressure
powerIf the boiler is not lit it could be a problem with power supply to the boiler
switched off or possibly blown a fuse
DHW pumpIf flashing this indicates either a store thermistor or PCB fault
FlowIf the boiler is not lit when a hot tap is opened this could mean there is a
lack of water flow or possible flow switch problem
DemandIf not lit this indicates either timer or programmer is not calling for hot water /
switch is not set to constant
BurnerIf flashing this indicates a PCB fault

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