Troubleshooting Problems

Find practical, safe guidance for common issues with low-carbon home technologies.

Heat pumps

• Heat pump error code: High pressure

  Understanding and resolving common high-pressure faults in heat pump systems, often caused by poor water flow.

• Heat pump flow temperature too high

  Why a high flow temperature is reducing your heat pump's efficiency and how to lower it to save money on your electricity bills.

• Heat pump icing up

  Identifying when ice on your outdoor unit is a normal part of operation and when it indicates a technical fault that needs fixing.

• Heat pump noisy at night

  Understanding why your heat pump might seem louder at night and how to address unusual noises.

• Heat pump short cycling

  Why your heat pump is turning on and off too frequently and why this is a problem for efficiency.

• Hot water not hot enough from heat pump

  Why your hot water feels lukewarm and how to adjust your heat pump settings to ensure comfortable bath and shower temperatures.

• Radiators lukewarm with heat pump

  Why your radiators don't feel 'hot' like they did with a gas boiler, and whether it's actually a problem.

• Underfloor heating slow to warm

  Why your underfloor heating takes hours to reach the right temperature and how to optimize your heat pump settings for comfort.

Insulation

• Black mould around windows

  How to identify, treat, and prevent black mould growth specifically on or near window frames.

• Cavity wall insulation slumping

  Identifying and resolving the issue where cavity wall insulation settles or slumps, leaving cold spots and increasing the risk of condensation.

• Condensation worse after insulation

  Why your home feels 'damper' or shows more condensation after you've added insulation, and how to fix it.

• Draughty floorboards after insulation

  Why you are still feeling cold air through your floorboards after installing insulation and how to seal gaps effectively.

• Extract fan dripping water

  Why your bathroom or kitchen extract fan is dripping water and how to insulate the ductwork to prevent condensation buildup.

• Loft insulation touching roof felt

  Why you must prevent your loft insulation from touching the roof felt to avoid condensation, rot, and structural damage to your roof timbers.

• Solid wall insulation cracking

  Why cracks appear in your external wall insulation (EWI) render and how to tell if they are cosmetic or a sign of structural failure.

Solar PV

• Inverter tripping or fault

  What to do if your solar inverter displays an error code or keeps switching itself off.

• Micro-inverter failure symptoms

  How to identify if one or more of your solar micro-inverters have failed and what to do about individual panel underperformance.

• Pigeon nesting under solar panels

  How to prevent and resolve issues caused by pigeons nesting under your solar panels, including noise, mess, and fire risks.

• Solar generation lower than expected

  Why your solar panels might not be producing as much electricity as you anticipated and how to investigate.

• Solar inverter overheating

  Why your solar inverter is getting too hot and how to improve its cooling to prevent automatic power reductions and hardware damage.

• Solar monitoring app not syncing

  How to fix connection issues between your solar inverter and its monitoring app, ensuring you can track your energy generation and savings.

• Solar panels yellowing or delaminating

  How to spot the signs of material failure in your solar panels and what 'yellowing' or 'delamination' means for your system's efficiency and safety.

Home batteries

• Battery discharging to grid unexpectedly

  Why your home battery is sending its stored power back to the grid instead of saving it for your home, and how to fix your inverter settings.

• Battery losing capacity quickly

  Is your home battery degrading too fast? Learn how to distinguish between natural degradation and a fault in your battery management system (BMS).

• Battery making clicking noises

  Why your home battery or inverter is making clicking or clunking sounds and how to tell if it's a normal relay operation or a sign of a fault.

• Battery not charging from solar

  Troubleshooting why your home battery remains empty even when your solar panels are generating plenty of power.

• Battery stuck at certain percentage

  Why your home battery refuses to charge past a certain point or won't discharge below a specific level, and how to reset your State of Charge (SoC) calibration.

• Emergency power supply not working

  Why your battery backup (EPS) failed to turn on during a power cut and how to ensure your home's essential circuits are protected.

EV charging

• EV cable locked in charger

  How to safely release an electric vehicle charging cable that is stuck or locked in the charging unit or vehicle port.

• EV charger app connection lost

  How to restore the connection between your smartphone and your EV charger, often caused by home Wi-Fi or server issues.

• EV charger lights flashing red

  A red flashing light on your EV charger indicates a safety fault. Learn what the different patterns mean and how to reset your unit safely.

• EV charger tripping RCD

  What to do if your electric vehicle charger causes your home's power to trip.

• EV charging interrupted randomly

  Why your EV stops charging before it's full and how to identify if the issue is with your car, the cable, or the home charger.

• EV charging slower than expected

  Why your electric car is taking longer to charge than the '7kW' or '22kW' advertised speed.

• RFID card not working on charger

  Why your RFID card or key fob is failing to start your EV charging session and how to troubleshoot the reader and card authentication.

Smart controls

• Smart hub offline frequently

  How to fix a smart home hub that keeps losing its connection, ensuring your heating, lighting, and energy monitoring stay online.

• Smart thermostat not reaching setpoint

  Why your smart heating controls might be failing to get your room to the desired temperature.

• Smart TRV noisy at night

  Why your smart radiator valves are making whirring or grinding noises at night and how to adjust your settings for a quieter bedroom.

Tariffs

• Bills higher after heat pump install

  Analyzing why your energy costs might have increased after switching from a gas boiler to a heat pump.

• Economy 7 or smart meter confusion

  Navigating the complexities of multi-rate tariffs, old legacy meters, and modern smart meter upgrades.

Written by NetZeroNow | Last updated on 2026-03-23