Vent Axia Repair in Ireland — Professional Maintenance and Diagnostics
If your Vent-Axia MVHR system is noisy, losing airflow, entering constant boost mode or showing error codes, fast repair is essential to protect indoor air quality and prevent long-term damage. Our technicians repair all Vent-Axia models, including Advance S, Advance SX, Sentinel Kinetic, Kinetic Plus and BH units. We diagnose faults, restore airflow and fix performance issues across Dublin and nationwide.
Common Vent-Axia Fault Symptoms
– Reduced airflow on supply or extract
– Loud noise, vibration or fan rumbling
– Frequent boost mode with no humidity present
– Fan not running (Left Fan Fault 01 / Right Fan Fault 02)
– Thermistor errors (04, 08, 16, 32)
– Humidity sensor faults (64, 128)
– “Check filter” message repeating
– Filter timer not resetting
– Bypass stuck open or closed
– Cold air supply in winter
– Condensate leaks or moisture around the unit
– Frost protection always active
– Controller not responding
– High humidity or window condensation
– Stale odours due to weak extract
Eco Vent provides rapid diagnostics, airflow testing and commissioning to restore your system to stable, efficient and silent operation.
Vent Axia Models We Repair
Eco Vent provides full diagnostics and repair for the entire Vent-Axia MVHR range installed across Ireland. Every repair follows TGD Part F (Ventilation 2019) and S.R. 54:2014+A2:2022, ensuring correct airflow, safe operation and fully compliant commissioning.
Below is an overview of the main Vent-Axia units we service most often, including typical faults, installation issues and what our repair process covers.
Sentinel Kinetic (All Variants)
Typical unit faults:
- Fan faults 01/02 caused by motor scroll wear
- Thermistor failures 04, 08, 16, 32
- Humidity sensor failures 64, 128
- Bypass actuator sticking (especially in older units)
- Frost protection stuck active
- “Check filter” message not clearing after reset
- Condensate leaks around the base of the unit
Common installation issues:
- Uninsulated ductwork to atmosphere causing thermal shock
- Incorrect condensate fall or dry traps
- Reversed supply/extract on first fix
- Undersized ductwork (100 mm where 125 mm is required)
- Valves adjusted randomly after renovation works
What we do:
- Full diagnostics of sensors T1–T4
- Correct airflow commissioning to design requirements
- Bypass motor repair and calibration
- Frost logic reset and preheater verification
Table of Contents
Sentinel Kinetic Plus
Typical unit faults:
- Bypass motor jamming in mid-position
- Noticeable fan noise at 40–60 l/s
- Overboost activation without RH demand
- Reduced airflow despite clean filters
Common installation issues:
- Overly long duct runs
- Valves installed too close to obstructions
- No acoustic ducting on supply
What we do:
- Bypass repair
- Noise and vibration analysis
- Full airflow balancing and commissioning
Kinetic B / BH (with internal humidistat)
Typical unit faults:
- Humidity oversensitivity → constant boost
- RH drift, especially during cold nights
- Fan noise on ramp-up
- Filter warnings appearing every few weeks
Common installation issues:
- Outdoor ducts not insulated → incorrect humidity readings
- High pressure drop on long extract branches
What we do:
- RH algorithm calibration
- Airflow resistance correction
- Summer bypass optimisation for damp homes
Kinetic High Flow
Typical unit faults:
- Strong vibrations at higher static pressures
- Rapid fan wear at 70–120 l/s
- Bypass flap sticking during winter
- Frost protection triggering at mild temperatures
Common installation issues:
- Undersized ductwork for high flow rates
- No acoustic attenuation in bedrooms
What we do:
- High-flow commissioning
- Bypass servo repair
- Extract/supply balancing for large houses
Advance S
Typical unit faults:
- Temperature/Humidity sensor drift (T1/T3)
- Motor assembly noise
- Boost triggering without input
- Fault codes 01–128 linked to sensor failures
Common installation issues:
- No pressure test after installation
- Incorrect condensate routing
What we do:
- Sensor diagnostics and replacement
- Full airflow balancing
- Condensate system correction
Advance SX
Typical unit faults:
- Constant Airflow Mode malfunction
- Flow sensors contaminated or failed
- Excessive boost from humidity algorithm
- Bypass flap stuck after summer operation
Common installation issues:
- Tight duct bends increasing resistance
What we do:
- Flow sensor cleaning and recalibration
- Constant Volume mode tuning
- Bypass servo repair
- Full commissioning after renovations
Vent Axia Not Working – Common MVHR Faults
Vent-Axia systems are highly reliable, but once airflow drops or sensors drift, the unit quickly loses efficiency.
Our troubleshooting process follows TGD Part F airflow requirements and S.R. 54:2014+A2:2022 commissioning standards to identify the exact fault and restore correct performance.
Below are the most frequent issues we diagnose in Irish homes, including units operating with error codes, noise, low airflow or incorrect humidity readings.
Low or Unbalanced Airflow
Low airflow is one of the most common MVHR complaints. It is typically caused by:
- Blocked or incorrect filters
- Motor wear or scroll contamination
- Flow sensors drifting out of calibration
- Undersized ductwork or high static pressure
- Valves fully closed after renovation or painting
- Extract branch resistance exceeding design limits
How we fix it:
We measure supply and extract using calibrated equipment, check pressure drops, verify duct dimensions and reset the commissioning profiles to meet design or TGD Part F requirements.
Excessive Noise or Vibration
Fan noise can indicate:
- Worn motor bearings
- Imbalanced impellers
- Loose internal mountings
- Bypass flap partially stuck
- High external static pressure
- Incorrect duct reducer sizing
How we fix it:
We stabilise the fans, clean motor scrolls, check bypass movement, confirm correct duct sizing and optimise fan curves for quiet operation.
Constant Boost Mode (False RH or LS Trigger)
Units often remain in boost due to:
- Faulty humidity sensors (64 / 128)
- Drift in internal RH algorithm
- Incorrect LS wiring
- High moisture load in cold weather
- Extract duct leaks pulling air from cold voids
How we fix it:
We recalibrate humidity triggers, correct LS inputs, reseal extract branches and adjust RH thresholds according to dwelling type.
Fault Codes & Sensor Errors
Vent-Axia units report faults using internal codes. The most common include:
- 01 / 02 — Left or Right Fan Fault
- 04 / 08 — Thermistor Fault (Left / Right)
- 16 / 32 — Centre Thermistor Faults
- 64 / 128 — Humidity Sensor Faults
Typical causes:
- Wiring failures
- Sensor drift
- Moisture ingress
- Motor load spikes
- Blocked airflow path
How we fix it:
We test each sensor, check PCB connections, verify motor load and replace faulty components using genuine Vent-Axia parts.
Summer Bypass Not Working
Symptoms include:
- Hot air entering bedrooms during summer
- Bypass stuck open or closed
- “Fresh mode” not activating
- Incorrect indoor/outdoor temperature readings
How we fix it:
We test actuator movement, recalibrate T1/T3 sensors and verify bypass thresholds according to the Vent-Axia specification.
Frost Protection Always Active
A system in permanent frost mode will have:
- Very low supply airflow
- High extract airflow
- Cold rooms
- No heat recovery
Probable causes:
- Failed thermistors
- Blocked outdoor duct
- Preheater malfunction
- Incorrect outdoor temperature readings
How we fix it:
We check ducts, verify temperature sensors, inspect the preheater module and restore normal frost logic.
Vent Axia Check Filters Message – Won’t Reset
This is usually caused by:
- Incorrect filter fitting
- Faulty filter timer
- Blocked airflow path
- Drifted pressure sensors (Advance SX)
How we fix it:
We confirm correct filter grade, clean or replace filters, reset the internal timer and test pressure sensors.
Condensate Leaks or Moisture in the Unit
Leaks typically happen when:
- The trap is dry or incorrectly installed
- The fall is less than recommended
- Freezing conditions block the pipe
- Condensate is connected to incorrect side (LH/RH handing issue)
How we fix it:
We correct the trap, re-route the condensate, insulate external sections and ensure proper fall as per S.R. 54 guidelines.
Vent Axia Not Working Controller
Common causes include:
- Damaged data cable
- PCB communication errors
- Power interruptions
- Software freeze
How We Fix it
We reset the controller, inspect the PCB, update configuration and restore the correct display and control functions.
Our Vent Axia Maintenance and Repair Process
A correct repair requires both technical diagnostics and proper MVHR commissioning. We follow a structured process to identify faults, restore airflow and ensure the system performs safely and efficiently across all Vent-Axia models.
Initial System Assessment
We begin by checking supply and extract airflow, fan noise, filter condition, controller behaviour, valve positions, duct insulation and external terminals. This tells us whether the fault is inside the unit or within the duct system.
Full Diagnostics and Sensor Testing
We read all internal fault codes, verify thermistors (T1–T4), test humidity sensors, check bypass movement, examine frost protection behaviour and confirm correct signal inputs. This helps pinpoint the exact failure instead of guessing.
Component Testing and Repair
We repair or replace fan motors, scroll assemblies, temperature sensors, humidity sensors, bypass actuators, PCB terminals and wiring faults. When required, we use genuine Vent-Axia parts for long-lasting reliability
Airflow Balancing and Commissioning
After repairing the system, we rebalance supply and extract flows and restore the correct performance profile. This includes valve adjustments and verifying that the system meets proper airflow requirements.
Final Testing and System Verification
We confirm frost logic, bypass operation, filter timers, LS inputs and user mode schedules. The system must operate quietly, consistently and within correct performance ranges before the repair is considered finished.
Homeowner Handover
We explain the cause of the fault, what was repaired, how to manage filters and how to prevent the issue from returning. This ensures long-term reliability and peace of mind.
Estimated Cost: 400 euro
Vent Axia Repair Costs in Ireland
Typical Vent-Axia Repair Pricing
Repair costs depend on the unit model, the type of fault and the condition of the installation. Most homes require standard diagnostics and minor component repairs, while older MVHR units or heavily restricted ductwork may need more extensive work.
– Standard diagnostic visit: €120–€150
– Fan motor replacement: €250–€350 per fan
– Sensor replacement (thermistor / humidity): €90–€160
– Bypass actuator repair or replacement: €250–€360
– Controller or wiring repair: €150–€220
– Condensate system correction: €80–€180
– Full airflow balancing & commissioning: €300
These ranges cover the most common faults seen in Vent-Axia Sentinel Kinetic, Advance S/SX, Kinetic Plus andHigh Flow.
What Affects the Final Cost?
Costs vary depending on the model, access to the unit, ducting resistance, airflow imbalance, sensor condition, age of the system and the severity of the problem. Homes with older ductwork or incorrectly installed units often require additional balancing or corrective work.
Repair vs Replacement
Most Vent-Axia units can be repaired cost-effectively, especially when issues are related to sensors, fans, filters or bypass actuators. Replacement is only recommended when the unit is very old, severely worn or unable to meet the required airflow performance.
Transparent Pricing
We always explain findings before starting repair work. No hidden fees — you approve everything before it happens.
Vent Axia Maintenance and Repair FAQ
Why is my Vent Axia not working?
Typical faults include fan motor errors (01/02), blocked filters, stuck bypass flaps, sensor failures, or wiring issues within the controller.
Installation problems—such as reversed ducts, incorrect condensate routing, or poor commissioning—can also cause the unit to stop operating correctly.
Why is my Vent-Axia making noise?
Excess noise usually comes from worn fan bearings, dirty impellers, high duct resistance, or a partially stuck actuator.
Long duct runs, uninsulated ductwork, or incorrect duct reducers can also increase sound levels throughout the system.
Why is my Vent-Axia stuck in boost mode?
This is commonly caused by humidity sensor drift, incorrect LS (live-switch) wiring, high moisture loads, or leaking extract ducts.
Recalibrating sensors, correcting LS inputs, and adjusting airflow settings typically resolves the issue.
What does “Check Filter” mean?
This alert indicates reduced airflow caused by dirty filters, blockages, or a pressure imbalance.
If the message appears frequently, the unit may also have a deeper airflow or sensor-related issue that requires inspection.
How do I reset the filter warning?
Navigate to Settings → Reset Filter → Confirm.
If the warning does not clear, the system may have a pressure fault, heavily blocked filters, or a failing sensor that needs attention.
Why is my unit stuck in frost protection?
Frost protection issues are typically caused by thermistor faults, freezing outdoor conditions, blocked external ducts, or problems with the preheater.
Testing the sensors and restoring correct frost logic usually resolves the problem.
How often should Vent-Axia be serviced?
Most Vent-Axia units require servicing every 12–18 months, including filter replacement, airflow testing, cleaning of key components, and sensor verification.
How much does Vent-Axia repair cost?
Standard repairs usually range from €150–€400, depending on the type of fault.
More complex issues—such as bypass actuator failures or full motor assembly replacements—may cost more.
Can older Vent-Axia units be repaired?
Yes.
Older models can often be restored with new bearings, controller repairs, filter upgrades, duct corrections, or full system rebalancing. Many units that appear “beyond repair” can be returned to reliable, efficient operation.
Vent Axia Not Working ?
Book Professional Repair in Ireland
A poorly performing Vent-Axia MVHR system can lead to high humidity, noise, low airflow, stale odours and rising heating costs. Whether your unit is showing error codes, stuck in boost mode, losing airflow or simply not running the way it should, a professional repair will restore efficiency and comfort.
Eco Vent provides Vent Axia maintenance and repair service for all models, including Sentinel Kinetic, Advance S, Advance SX, Kinetic Plus, High Flow, BH and older MVHR units. We offer fast response across Dublin and nationwide, complete diagnostics, genuine parts and commissioning after every repair.
Get your system running smoothly, quietly and efficiently again.