Alpha boiler repair across London
We repair current and older Alpha boilers. Ring us, day or night.
- Alpha E-Tec and InTec repaired and serviced
- All our engineers are Gas Safe registered
Makes we repair
How does booking an Alpha repair work, and what does it cost?
Booking: ring us any time, day or night, or send your details and we ring you back. We'll ask what the boiler is doing, and its model and any code on the display if you can see them. You don't need to know what's wrong. Finding the fault is the engineer's job. Then we tell you when an engineer can come, anywhere in Greater London.
What it costs: a repair's price depends on the part it needs, how long the job takes and when it's done. Our rates are higher in the evening, overnight and at weekends. Once the engineer has found the fault, the rate for the repair is agreed in writing before any work starts.
What happens on an Alpha repair visit?
A repair visit has three stages.
1. Before anything is touched
The engineer covers the floor around the boiler and asks what you have seen and heard since you rang.
2. Finding the fault
The engineer tells you which part has failed, whether they have it with them or must order it, and how long the work should take. No work is done until you say yes.
3. The repair
The engineer fits the part and checks the boiler runs as it should before leaving. The repair is guaranteed for 12 months, covering the parts we fit, the labour and any return visit.
What goes wrong on Alpha boilers most often?
Alpha's own help pages come back to the same problems:
- Losing pressure. The gauge should read 1 to 1.5 bar, and the user guide shows how to top it up. If the pressure keeps dropping, it may be a leak, and the boiler needs an engineer.
- A frozen condensate pipe. In a frost the pipe outside can freeze, and the boiler gurgles and stops. Warm water thaws it.
- No hot water. Alpha's list of causes starts with a power cut, a tripped fuse or a water supply problem. It also takes in a frozen condensate pipe, low pressure, a leak, or a code on the display.
- Cold radiators. Cold at the top means air, and bleeding the radiator lets it out. Cold at the bottom or in patches points to sludge, an engineer's job.
- Heating that comes on at night or in cold weather. Alpha's answer is that the frost or night-time setting on the controls is set too high, and it suggests 8 to 12°C.
- A new boiler, and heating that doesn't work. Alpha points to a system that wasn't cleaned, since sludge can damage a new boiler and void its guarantee.
Whichever it is, we'll ask what the boiler is doing when you ring.
Sources: Alpha's FAQs, and its pages on boiler pressure and frozen condensate pipes.
Alpha fault codes and what they mean
Alpha's manuals give each fault a number, written E01, E10 and so on. The E-Tec Plus NX has a longer list of its own, numbered up to 139. Even so, the six codes below mean the same on it as on every other E-Tec and Evoke.
Alpha's user guides say to press RESET once, and to ring an engineer if the code comes back. After five resets the boiler shows E08.
E10Alpha E10: the system pressure is too low
What it means: The pressure switch has found too little water pressure in the heating for the boiler to run safely.
Possible causes, as the manual lists them:
- the expansion vessel's charge
- a leak in the system
- the pressure relief valve letting water out
- the pressure switch itself
What you can do: with the system cool, top up as the user guide shows, to just above 1 bar, in the green, then reset. If the pressure keeps dropping, there is likely a leak or a fault on the vessel or the valve, which needs an engineer. An E-Tec R on an open vented system doesn't show E10.
E02Alpha E02: the overheat sensor has tripped
What it means: The water in the boiler got too hot, so the overheat sensor shut it down.
Possible causes, as the manual lists them:
- the pump or a poor flow of water
- a blocked heat exchanger
- air in the heat exchanger
- valves or pipework outside the boiler
With zone valves fitted, the system needs a bypass. On older models the overheat thermostat, or a thermal fuse, can be the cause.
What you can do: press RESET once. Every cause on the list is an engineer's job, so if E02 comes back, ring us.
E03Alpha E03: the flue gas is too hot
What it means: The flue sensor tripped because the gases leaving the boiler were too hot. E47 usually comes first, when the boiler turns itself down. If the flue keeps heating up, the boiler locks out on E03.
Possible causes, as the manual lists them:
- a blocked or poor flow of water
- a heat exchanger blocked on the gas side
- a restricted flue
- the flue sensor
- air in the heat exchanger
What you can do: press RESET once.
E16Alpha E16: a fan fault
What it means: The fan isn't running as it should, from an electrical or a mechanical fault.
Possible causes, as the manual lists them:
- the fan's wiring
- the fan
- the main board
What you can do: press RESET once. The fan sits inside the boiler's sealed case, so if E16 comes back, it needs an engineer.
E38/E43Alpha E38 and E43: the flame lit, then went out
What it means: E38 means the flame lit, then its signal was lost. The boiler clears the burner with the fan and tries again. If it relights, no reset is needed, and the boiler logs it.
E43 means the flame was lost again and again, and the boiler has locked out. Alpha links E43 to a flue exposed to strong wind, and the fault history records it as E38.
Possible causes, as the manual lists them:
- the sensing electrode and its lead
- flue gases drawn back into the boiler
- the gas valve
- the flue and its terminal
- the gas pressure
- the combustion settings
- the burner's earth
What you can do: at E43, press RESET once. The gas valve and the combustion are on the list, so don't keep resetting the boiler. If E43 comes back, ring us.
E01Alpha E01: the boiler tried to light and found no flame
What it means: The boiler tried to light and found no flame.
Every cause of E01, and what fixes it, is on the E01 fault code page.
MoreEvery other Alpha code, in one list
Every other code in Alpha's manual for the E-Tec Plus 28, 33 and 38, the list the E-Tec, Evoke and E-Tec S share.
E04A fault in the gas valve's electrical circuit
Possible causes
The gas valve's lead or plug, the gas valve, or the main board
E05The heating flow sensor's reading is out of range
Possible causes
The sensor or its wiring
E06The hot water sensor's reading is out of range
Possible causes
The sensor or its wiring
E08The reset limit, reached after five resets in a row
Possible causes
Whatever caused the lock-outs, which the engineer reads in the boiler's fault history
E12The optional cold water inlet sensor's reading is out of range
Possible causes
The sensor or its wiring
E15The boiler's settings don't match its parts
Possible causes
A setting, for the engineer to correct
E20A flame is sensed while the gas valve is shut
Possible causes
The sensing electrode or its lead, a short on its wires, or the main board
E22, E25A software fault on the main board
Possible causes
The main board
E23The return sensor's reading is out of range
Possible causes
The sensor or its wiring
E24A button on the control panel is stuck
Possible causes
A jammed button on the panel or the board
E27Overheating, from too little water moving through the boiler
Possible causes
Air in the heat exchanger, closed valves, or the pump's power, wiring or a seized pump
E29The flue sensor's reading is out of range
Possible causes
The sensor or its wiring
E31Contact with an Alpha Climatic control is lost
Possible causes
Its wiring, distance or radio interference, the control, or its batteries
E37The mains voltage is too low for the boiler to run
Possible causes
The electricity supply, or a loose connection
E45A sudden big gap between the flow and return temperatures
Possible causes
Poor water flow, the pump's setting or the return sensor. The boiler turns itself down and recovers.
E47The flue gas is too hot, so the boiler turns itself down
Possible causes
Air, poor water flow, a heat exchanger blocked on the gas side, the flue or its sensor, or the pump. E03 follows if the temperature keeps rising.
E51A wireless Climatic control has lost its radio link
Possible causes
The control's batteries
E60The pump is stuck, or has an electrical fault
Possible causes
A seized pump shaft, its wiring, or the pump
E61Air in the pump, or too little flow round the heating
Possible causes
Closed valves, low pressure, or air in the system
E70The return sensor reads hotter than the flow sensor
Possible causes
Wiring, sensors swapped or badly fitted, or a blocked system
E75, E76The flow or return sensor has failed
Possible causes
The wiring, or the sensor
A blank screenThe main board's fuse has blown
Possible causes
The wrong power supply, a seized pump, or a part drawing too much current
A red light on the pumpA pump fault
Possible causes
Low voltage, a seized pump, or a fault in the pump, its wiring or the board
The E-Tec NX and Evoke NX combis leave out E12, E22, E25 and E27, and add E49. E49 means the return water got too hot, and the boiler needs a reset. The E-Tec NXS leaves out E22, E25 and E27, and the E-Tec S leaves out E22, E27 and E70.
The E-Tec R adds four codes:
- E44, when the boiler tried to light again and again for the longest time allowed
- E46, when an optional thermostat's circuit is open
- E49, when the return water got too hot
- E71, when there is no rise in temperature after lighting, from air or closed valves
On the E-Tec R, E06 is an internal wiring fault and E12 the cylinder sensor.
The InTec2 and the Eco2 Plus. The codes up to E31 mean much as above. These are their own, many of them for the gas valve and the combustion.
E44It tried to light again and again for the longest time allowed
Possible causes
The heating switched on and off quickly at the room thermostat, or a hot tap turned on and off fast
E46An optional outside safety sensor's circuit is open
Possible causes
A damaged or wet sensor or cable, or a missing link on the terminals
E59The mains frequency is wrong
Possible causes
The electricity supply, or the board
E62A full calibration is needed
Possible causes
A new main board, or changed air and gas settings
E72A quick calibration is needed
Possible causes
An engineer's setting
E73The flow sensor and the safety sensor disagree
Possible causes
The sensors, poor circulation or a blockage
E74The safety flow sensor has failed
Possible causes
The sensor
E77, E78, E79A fault in the gas valve's control
Possible causes
The electrode, the gas pressure, or the gas valve
E80A board fault on the gas valve's control
Possible causes
The valve's wiring, the valve or the electrode
E84Low gas pressure, so the boiler turns itself down
Possible causes
A gas valve on the supply not fully open, the working pressure, or the gas valve. The boiler recovers once the pressure is right.
E87, E88A fault in a part of the gas valve's control
Possible causes
The board and valve connections, or the board
E89The flame is unstable
Possible causes
Flue gases drawn back in, the electrode, the burner, the calibration, then the gas valve or the board
E90, E93The flame signal is out of range, over a long or a short spell
Possible causes
As E89
E91The flame was lost again and again while lighting
Possible causes
The calibration, then the gas valve or the board
E92The fan speed correction has reached its limit
Possible causes
As E89
E94A combustion problem
Possible causes
The gas pressure and rate, the flue, the electrode, the burner or the calibration
E95The flame signal is breaking up
Possible causes
The electrode and its lead, the burner, the calibration or the board
E96The flue or the air intake is blocked or restricted
Possible causes
The flue and air paths, or the fan
E98Too many software errors
Possible causes
The main board
E99A general lock-out
Possible causes
The main board, where a reset won't clear it
- -A reading or a setting is out of range
Possible causes
A sensor, or a setting
A blank screenThe board has shut down to protect itself after an electrical fault
Possible causes
The fan, the diverter valve's motor, the gas valve or their wiring
The InTec C, X and GS, the InTec GS2 and the Eco use the E-Tec list up to E51. On them, E44 and E46 are as in the list above, and E25 means the flue temperature is rising fast.
The CD combis' lights.
- D steady: the power is on.
- C steady: the burner is lit.
- A flashing: a temperature sensor fault, which needs an engineer.
- B flashing: the overheat thermostat has tripped. Turn the selector to reset. If it happens again, ring us.
- B steady: the burner didn't light. Turn the selector to reset, and the boiler tries again after about 30 seconds.
- A and B flashing together: a blocked flue or a fan fault, which needs an engineer.
- A and B flashing in turn: the pressure is very low. The label inside the panel cover shows how to top it up.
- A flashing and B steady: a pump fault, or a poor flow of water. Either needs an engineer.
The current E-Tec Plus NX: every other code
From Alpha's manual for the E-Tec Plus 28NX, 33NX and 38NX, which lists each code by its number. A few of its codes aren't faults:
- 07, a test mode the engineer runs
- 83, the boiler switched off, shown on a remote control
- 138 and 139, a floor-drying or air-clearing cycle running
04The board sees a fault in the gas valve's supply, when there is a call for heat
Possible causes
The gas valve, or the board
05The flow sensor has a fault, and the safety thermostat has tripped
Possible causes
The sensor. The boiler won't start.
06The hot water sensor has a fault, though hot water still comes, below full strength
Possible causes
The sensor. Frost protection is off in the meantime.
08The reset limit, which blocks resetting for at least an hour after five resets in a row
Possible causes
Whatever caused the lock-outs
15The wiring or the settings don't match
Possible causes
The boiler's set-up. The boiler restarts by itself once it is right.
20A stray flame signal
Possible causes
A leak on the sensing circuit, or the flame control
23The return sensor has a fault, and the boiler won't start
Possible causes
The sensor
24A fault on the button panel
Possible causes
The panel. The boiler restarts by itself once it is right.
27Overheating from poor circulation
Possible causes
Closed valves, air, or a blocked pump
29The flue sensor has a fault, and the boiler won't start
Possible causes
The sensor
31Contact with the remote control is lost, or the control doesn't suit the boiler
Possible causes
The control, or its link to the boiler
36Communication on the boiler's data link is lost
Possible causes
The board, a zone unit or the link between them
37The supply voltage is too low
Possible causes
The electricity supply. The boiler restarts by itself once it is right.
44The gas valve stayed open longer than allowed without lighting
Possible causes
Lighting trouble. The boiler needs a reset.
45A sudden big gap between the flow and return temperatures
Possible causes
Poor circulation, the pump's setting or the return sensor. The boiler turns itself down and recovers.
46An outside safety thermostat, such as underfloor heating's, has tripped
Possible causes
Overheating on that circuit. That thermostat is reset once it cools.
47The flue is too hot, so the boiler turns itself down
Possible causes
The flue gas temperature. The boiler keeps running at lower power.
48The optional system flow sensor has a fault
Possible causes
The sensor. The boiler keeps running, with the temperature swinging.
49The return water got too hot, and needs a reset
Possible causes
Air, closed valves, or the pump
51No contact with a wireless Climatic control
Possible causes
The control, or its batteries
60The pump has stopped, from a blocked impeller or an electrical fault
Possible causes
The pump. The boiler restarts by itself once the pump is freed.
61Air in the pump
Possible causes
Air in the pump and the heating. The boiler restarts by itself once they are vented.
70The flow and return sensors are wired the wrong way round
Possible causes
The sensors' wiring. The boiler won't start.
75One or both temperature sensors have failed
Possible causes
The sensors. The boiler won't start.
76The temperature sensors' readings are drifting
Possible causes
The sensors. The boiler won't start.
98Too many software errors
Possible causes
The board's software. The boiler needs a reset.
- - - -A fault in the main board's hardware
Possible causes
The main board
The fault codes page explains how fault codes work on every make, and what each kind of code means.
Sources: Alpha's installation and servicing instructions and user guides for the E-Tec Plus NX, the E-Tec Plus, E-Tec, Evoke and E-Tec S and their NX models, the E-Tec R, the InTec, the InTec2, the Eco2 Plus and the CD combis.
Which Alpha boiler do you have, and how does it show a fault?
Alpha's boilers show a fault in one of three ways, depending on their age:
- a number on a screen
- an E flashing in turn with a number
- a pattern of lights
We'll ask for the model and the code when you ring.
Not every code is a fault:
- Sr means a service is due, and the boiler keeps running.
- A single dot means the boiler has been switched fully off. Holding the mode button for 2 seconds brings it back.
- On the E-Tec Plus NX, dl shows while the boiler clears air for about eight minutes after it is switched on.
- On an InTec, 96 counting down means the same thing.
How do you reset an Alpha boiler?
Each Alpha range resets its own way, as Alpha's user guides show:
- E-Tec Plus NX: the controls sit behind a flap. Press any button to wake the keypad, then RESET. If the keys don't respond, holding buttons 1 and 2 together for 5 seconds turns the keypad lock off.
- E-Tec Plus, E-Tec, Evoke, E-Tec S and the other NX models: press RESET.
- InTec and Eco2 Plus: with the gas and electricity on and the controls set, press reset.
- CD combis: turn the selector to the reset position, for no more than 2 or 3 seconds.
One reset is enough. If the code comes back, ring us. After five resets the boiler shows E08, and the E-Tec Plus NX then blocks resetting for at least an hour.
The pressure, with the system cold, should read:
- 1 bar, in the green on the gauge
- 1 to 1.5 bar on the E-Tec, Evoke and E-Tec S
- 1 to 1.2 bar on the E-Tec Plus NX
The E-Tec Plus and E-Tec Plus NX have a filling loop built in under the boiler, behind a cover. On the E-Tec, Evoke and E-Tec S, and their NX models, the installer fits one below the boiler. The user guide shows how to use each.
The pressure rises as the heating warms up, which is normal. If it goes too high, the user guide shows how to let a little water out at a radiator. An E-Tec R on an open vented system has no pressure to top up.
A frozen condensate pipe can be thawed where it is at ground level and easy to reach:
- Pour warm, never boiling, water slowly along the pipe, from its open end and its bends.
- Restart the boiler.
When a boiler won't fire up, and frozen condensate pipes.
After a power cut the boiler restarts by itself, though the timer may need setting again.
Sources: Alpha's user guides for each range, and its page on frozen condensate pipes.
Is your Alpha boiler still under guarantee?
Alpha's guarantee depends on the boiler:
- The E-Tec Plus NX has 10 years, and up to 13 with Alpha's PremierPack Pro, which includes its Cyclone Plus filter.
- The E-Tec NX, Evoke NX, E-Tec NXS and E-Tec R have 7 years, which Alpha's filter and protection packs can lengthen.
For the guarantee, the boiler must be:
- registered with Alpha within 30 days of fitting
- fitted by a Gas Safe registered engineer, with the Benchmark checklist filled in
- serviced every year by a Gas Safe registered engineer, with each service recorded in the Benchmark service record
Without the yearly service, Alpha's terms give no free repairs. While the guarantee runs, faulty parts are repaired or replaced free when Alpha or one of its appointed agents does the work. Alpha doesn't accept other engineers' invoices for attending or repairing the boiler.
The guarantee covers the boiler itself, not the radiators, pipes or valves, and not damage from sludge, scale or frozen pipework outside. Alpha asks for the boiler's serial number and the installer's details when you ring.
A boiler still under its maker's guarantee is usually repaired by the maker, at no charge, so ring Alpha first. Once the guarantee has ended, or for a fault it doesn't cover, ring us. We are an independent firm, with no connection with Alpha.
Sources: Alpha's warranty terms and conditions and its FAQs, its E-Tec Plus NX page and manual, its 2024 range brochure and the Evoke NX leaflet.
What does an Alpha boiler service cover?
Alpha asks for a service at least once a year, by a Gas Safe registered engineer, to keep the guarantee. The service in Alpha's manual starts with a flue gas reading, then covers:
- the flue and its terminal
- the controls
- leaks on the system
- the pressure and the expansion vessel
- the condensate trap and pipe
- gas tightness and electrical safety
All of it is recorded in the Benchmark service record, with a test of the inhibitor in the heating water. Sr on the display, or the maintenance symbol on the E-Tec Plus NX, means a service is due.
We service every Alpha model, and give you the rate on the call. What a boiler service includes, check by check.
Do you cover my part of London?
Yes: we travel all over Greater London, day and night, to repair Alpha boilers in every borough, north and south of the Thames. Pick your side of the river to see the areas.
North of the river
Every borough north of the Thames: Barnet and Enfield at the top, Hillingdon in the west, Havering in the east, and central London in between.
South of the river
Every borough south of the Thames: Richmond and Kingston in the west, Bexley in the east, and down through Croydon to Sutton and Bromley.
The other makes we repair
Every main make, combi, system and regular. Pick yours for its common faults, its codes and how we repair it.
Questions about Alpha boilers
Do I need to know what's wrong with my Alpha boiler before I ring?
No. Ring and say what the boiler is doing, or what you can see or hear, and we'll ask the rest. Finding the fault is the engineer's job.
Do you charge more in the evening or at weekends?
Yes. Our rates are higher in the evening, overnight and at weekends.
Can you repair an older Alpha boiler?
Usually, yes. It depends on the boiler's condition and whether its parts are still made. We'll ask for the model when you ring.
Is my Alpha boiler worth repairing?
Often, yes. Age alone doesn't decide it. What decides it is the rate for the repair against a new boiler, and how often the boiler has failed. The engineer gives you the rate for the repair, and the choice is yours. When a new boiler makes more sense.
Will a repair affect my Alpha guarantee?
While the guarantee runs, ring Alpha first. The maker usually repairs a boiler under guarantee itself, and its terms say who may work on it. Once it has ended, any Gas Safe registered engineer can repair it.
Do you fit Alpha's own parts?
Yes, the maker's own parts wherever they are available. Each repair is guaranteed for 12 months, covering the parts we fit, the labour and any return visit.
How much does an Alpha boiler repair cost?
The cost of a repair depends on the part, how long the job takes and when it's done. The rate is agreed in writing before the repair starts. How our rates work.
Why does my Alpha boiler keep losing pressure?
Alpha's manual names three causes of an Alpha boiler losing pressure, each for an engineer:
- the expansion vessel's charge
- a leak in the system
- the pressure relief valve letting water out
The user guide shows how to top up to 1 bar, in the green. If the pressure keeps dropping, ring us.
Why are the A and B lights flashing on my Alpha boiler?
On an Alpha CD combi, A and B flashing in turn means the system pressure is very low. The label inside the panel cover shows how to top it up. A and B flashing together means a blocked flue or a fan fault, so ring us.
What does Sr mean on an Alpha boiler?
Sr on an Alpha boiler means a service is due. It isn't a fault, and the boiler keeps running. Pressing RESET hides it for 24 hours, and the engineer clears it at the service.
How many times can I reset my Alpha boiler?
Once, then ring us if the code comes back, as Alpha's user guides say. After five resets the boiler shows E08, and the E-Tec Plus NX then blocks resetting for at least an hour.
Who makes Alpha boilers?
Alpha boilers are made by Alpha Therm, founded in 1966 and based in Kent. Since 2000 Alpha Therm has been part of Immergas, an Italian, family-owned heating maker founded in 1964.
Don't know what has failed? You don't have to.Ring and say what you can see or hear. Finding the fault is our job.
Calls answered 24 hours a day
A real person answers and gives you the rate on the call. No work starts until you say yes, and repairs are guaranteed for 12 months: parts, labour and any return visit.
