Sabre Boiler Repairs
Experienced Sabre Boiler Repairs specialists
Available 24 hours a day, 7 days a week
Insurance approved
All parts guaranteed for a year
Fully Gas Safe trained engineers
Sabre Boiler Repairs London
Gas Safe registered engineers • 24/7 call handling • London wide
Call Now: 0203 868 6251 | Request a Call Back
Tell us the LED light pattern and model. We will advise the safest next step.
Common models include Vokera Sabre HE 24, Sabre HE 25, Sabre 29, Sabre 35, and Sabre HE Plus. Common searches include Sabre red light flashing, Sabre boiler not firing, Sabre HE lockout, and Sabre green light fault.
We fix Sabre boiler faults and breakdowns across London, including red light lockouts, no heating, no hot water, low pressure, and ignition faults.
We also offer boiler servicing and boiler installation across London.
Quick Navigation
Safety First
Smell gas? Turn off the gas supply at the meter if it is safe to do so. Open windows. Leave the property. Call the National Gas Emergency Service on 0800 111 999. Do not use switches, and do not use naked flames.
CO alarm sounding? Open windows immediately. Leave the property. Call 999. Do not re-enter until cleared by emergency services.
Boiler leaking heavily? Turn off the boiler at the controls. If safe, turn off the water supply. Call an engineer.
Quick Checks Before You Call
Before calling an engineer, these safe checks may resolve simple issues with your Sabre boiler.
Check the gas supply
Is gas working at other appliances in your home? If not, check your meter and any prepayment credit.
Check the pressure gauge
Pressure is shown on a gauge (model dependent). It should read around 1.0 to 1.5 bar when cold. If it is low, you may need to top up using the filling loop (location varies by installation).
Check the thermostat
Is the room thermostat set above current room temperature? Are the batteries working?
Check the timer or programmer
Is the heating scheduled to be on? Check the clock is set correctly.
Try a single reset
Turn the mode selector to off, wait 10 seconds, then turn back to heating or hot water. If the fault returns, do not keep resetting. Call an engineer. If a red light returns after one reset, stop. Repeated resets can worsen underlying faults.
Check the condensate pipe
If your Sabre is a condensing model, the external condensate pipe can freeze in cold weather. Look for a white plastic pipe exiting through an outside wall. If frozen, pour warm water over it gently.
Sabre Symptoms and Fault Indicators
Sabre boilers use LED indicator lights rather than digital fault codes. LED patterns can vary by model and version. Tell us the exact light pattern you see, including whether lights are steady, flashing, or off.
If you smell gas, do not reset. Follow the Safety First steps above and call for help.
| LED pattern / symptom |
What it means |
What to do |
| Red light flashing |
Ignition lockout (model dependent). |
Check gas supply. Try one reset only. If it returns, call an engineer. |
| Red light steady |
Permanent lockout. Safety fault detected. |
Do not keep resetting. Call an engineer. |
| Low pressure on gauge |
Leak in system or expansion vessel issue. |
Top up to around 1.0–1.2 bar (cold) if confident. If it drops again, call an engineer. |
| Pattern not listed |
Sabre LED patterns vary by model. |
Call us with the exact LED pattern, model, and postcode and we will advise the safest next step. |
Need help now? Call 0203 868 6251 and tell us the LED pattern and model.
Most Searched Sabre Problems
If you are seeing a Sabre boiler lockout, red light flashing, or your boiler keeps cutting out, tell us the LED pattern and model and we will confirm the safest next step.
Red light flashing (ignition lockout)
A flashing red light on a Sabre boiler typically indicates ignition lockout. The boiler has tried to ignite but failed. Possible causes include gas supply issues, a worn ignition electrode, blocked venturi tube, or air pressure switch fault. Check gas is on elsewhere in the home. Try one reset by turning the selector to off for 10 seconds. If the red light returns, stop and call an engineer.
On older Sabre units, ignition issues can also relate to ignition leads, electrode condition, or gas valve faults (model dependent).
Low pressure
If the pressure gauge shows low pressure, the system may have dropped below the minimum threshold. If you are confident using the filling loop, top up to around 1.0–1.2 bar cold. If pressure drops again within days, there may be a leak, a pressure relief issue, or an expansion vessel fault. Do not keep topping up. Call an engineer to find the cause.
If pressure keeps dropping, check for radiator valve leaks, pressure relief discharge outside, or a failing expansion vessel.
No hot water but heating works (combi models)
On Sabre combi models, you may get heating but no hot water, or the reverse. This often points to a diverter valve issue. The diverter valve directs hot water between taps and radiators. When it wears or sticks, hot water delivery becomes unreliable. Call an engineer for diagnosis.
If hot water starts then goes cold, it can indicate a DHW flow sensor issue or plate heat exchanger scaling.
Why Sabre Boilers Develop Faults
Sabre boilers are part of the Vokera Sabre range, designed as combi boilers for domestic heating and hot water. Here is what we commonly see.
Blocked venturi tube
A blocked venturi tube is a common cause we see on Sabre HE boilers. The venturi tube is part of the air pressure switch system. When blocked, the boiler detects no airflow and locks out. Symptoms include the fan running but no ignition. This requires an engineer to clean or replace the venturi.
Air pressure switch faults
The air pressure switch confirms the fan is running and flue gases can escape safely. If the switch or its sensing tubes become blocked or faulty, the boiler will not fire. This is common on Sabre HE models after several years of use.
Thermistor and overheat issues
A fast flashing green light can indicate overheat protection has triggered. The primary thermistor or high limit thermistor may be faulty, or there may be circulation problems in the system. Sludge buildup or a failing pump can cause overheating.
Diverter valve wear
On Sabre combi boilers, the diverter valve directs hot water between heating and taps. After years of use, the valve can stick or fail. Symptoms include no hot water while heating works, or vice versa.
Sabre Models We Repair
We repair Vokera Sabre boilers in London, including Sabre HE 24, Sabre HE 25, Sabre 29, Sabre 35, and Sabre HE Plus models. Tell us the model from the data plate, usually found inside the front panel or on the casing.
Sabre boilers are part of the Vokera range. Parts availability is generally good. We check availability before attending and will advise honestly if a specific part is difficult to source.
Repair or Replace Your Sabre Boiler?
We help you decide based on age, reliability, and parts availability.
Repair makes sense when
- Boiler is under 10 years old
- This is the first major fault
- Parts are readily available
- Boiler has been regularly serviced
Replacement may be better when
- Boiler is 12 years old or more
- You have had multiple breakdowns recently
- Parts are obsolete or hard to source
- The boiler is undersized for the property
- Energy bills are higher than expected for the property size
Our engineers give honest assessments. If we cannot source parts or the repair is not cost effective, we will tell you.
Sabre Boiler Servicing
Annual servicing reduces breakdown risk and keeps your Sabre boiler running efficiently. See Boiler servicing London.
Landlords and Letting Agents
We provide boiler repairs and gas safety certification for landlords across London. See Landlord gas safety certificate (CP12).
Sabre Repairs Across London
London wide coverage for Sabre boiler repairs. Book an engineer or view our London areas we cover.
Have your postcode and model number ready and we’ll confirm the quickest appointment slot.
Other Boiler Brands We Repair
Worcester • Vaillant • Ideal • Baxi • Glow worm • Viessmann • Potterton • Vokera • Alpha • Ferroli
View all brands
Sabre Boiler Repair FAQs
Why is my Sabre boiler red light flashing?
A flashing red light indicates ignition lockout. The boiler tried to ignite but failed. Check gas supply is on. Try one reset by turning the selector to off for 10 seconds. If the red light returns, call an engineer.
What does a fast flashing green light mean on a Sabre boiler?
A fast flashing green light can indicate a temperature fault. This may mean the overheat thermistor has tripped. Allow the boiler to cool and try again. If it persists, call an engineer.
How quickly can you attend for a Sabre breakdown?
We offer same day attendance where slots are available. For no heating or hot water, we prioritise urgent breakdowns. Call our 24/7 line and we will advise availability.
Are Sabre boilers still made?
Sabre boilers are part of the Vokera range. Parts availability is generally good. We can source most Sabre parts and will advise before attending if any are difficult to obtain.
Related Services
Speak to Our Team
For safe next steps, call now or request a call back.
Call 0203 868 6251 | Book an Engineer
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