Why Does Your Boiler Start Then Stop?
If your boiler in Curdridge is flickering on and off—commonly called short cycling—you’re not alone. Older homes in Curdridge and nearby areas like Bordon, Alton (GU34) and Liphook often face intermittent heating issues due to aging pipework, thermostat faults and low system pressure. Short cycling can waste energy, lead to uneven heating and increase the risk of a heating breakdown.
Common Causes of Short Cycling
- Thermostat faults or miscalibration
- Low water pressure in the boiler
- Air trapped in radiators causing cold spots
- Faulty pump or diverter valve
- Overheating triggering the safety cut-out
Thermostat Faults and Calibration
An inaccurate or failing thermostat may signal the boiler to turn off prematurely. Many homes in Curdridge still use older dial or mercury thermostats that drift over time. Upgrading to a digital programmable thermostat can improve temperature control and reduce rapid on/off cycles.
Water Pressure Problems
Boilers require a minimum water pressure—usually around 1.0-1.5 bar—to operate correctly. If the pressure drops below this level, the boiler will fire up then shut down as a safety precaution. Check your pressure gauge and top up via the filling loop if it falls under the recommended range.
Air Trapped in Radiators
Air pockets in your heating system lead to poor circulation and cause the boiler to overheat quickly. Bleed your radiators to release trapped air. If you live near Farnham or GU35 areas like Bordon, this simple step can restore even heat distribution and prevent the boiler from cycling off.
Pump and Valve Failures
A malfunctioning pump or diverter valve can interrupt water flow, making the boiler think there’s a fault. Listen for unusual noises or gurgling sounds. If the central heating pump struggles to circulate water, it’s time to call in boiler repair experts.
Overheating and Safety Cut-Outs
Modern boilers include a safety thermostat that trips if the heat exchanger gets too hot. Sludge build-up or limescale restricts water flow, causing rapid overheating. Powerflushing your system every few years can clear debris and keep your boiler running smoothly in Curdridge, Whitehill and surrounding GU32 homes.
Troubleshooting Steps for Homeowners
- Check thermostat settings and replace batteries if needed.
- Inspect the pressure gauge and re-pressurise to 1.2 bar.
- Bleed radiators starting with the lowest floor.
- Listen for unusual boiler or pump noises.
- Reset the boiler following the manufacturer’s guide.
When to Call a Professional Gas Safe Engineer
If your boiler still starts then stops after basic checks, it’s time to seek expert help. A qualified Gas Safe engineer can diagnose electrical faults, replace faulty components and carry out thorough boiler servicing to restore reliable performance.
Preventative Maintenance Tips
Regular upkeep prevents short cycling and extends boiler life. Follow these tips all year round:
- Book an annual service to check combustion efficiency, safety devices and controls.
- Bleed radiators and check pressure monthly.
- Keep pipework insulated—particularly in colder GU35, GU34 and GU32 areas.
- Install magnetic filters to catch sludge and debris.
Considering a New Boiler?
Older boilers in Curdridge’s vintage homes may be beyond economical repair. If repair costs keep rising or you face repeated heating breakdowns, a new boiler installation could be more efficient and reliable. Modern condensing boilers offer quieter operation, higher efficiency and reduced energy bills.
Boiler Cover and Peace of Mind
Unexpected boiler failures can be costly, especially during cold snaps. Consider a comprehensive boiler cover plan that includes annual servicing, unlimited call-outs and parts cover. It’s a small monthly fee for big savings if your boiler starts then stops unexpectedly.
Frequently Asked Questions
Q: Why does my boiler pressure keep dropping?
A: Leaks in the system, a faulty pressure relief valve or recent radiator bleeding can lower pressure. Check for damp patches and top up via the filling loop.
Q: Can I reset my boiler myself?
A: Most boilers have a reset button—however, repeated resets indicate a deeper fault. Contact a qualified engineer if problems persist.
Q: How often should I get my boiler serviced?
A: Annual boiler servicing by a Gas Safe engineer is recommended to keep your system safe, efficient and under warranty.
If you need help with your heating or boiler, our local engineers are here to help. Call us on (01420) 558993 or book online at embassygas.com/book.
Written by Embassy Gas — your local heating experts covering Curdridge, Bordon, Alton, Liphook and surrounding areas.