Many homeowners switch off their heating systems during the summer months and forget about their boiler entirely. While this might seem sensible, neglecting your system can lead to costly repairs, reduced efficiency, and even health risks such as Legionella bacteria.
As a gas engineer, I always advise customers that summer is actually the perfect time to maintain your boiler and heating system properly.
Why Summer Boiler Care Matters
During summer:
• Your boiler is used less frequently
• Water can sit stagnant in pipes and tanks
• Mechanical parts can seize due to inactivity
This creates the perfect conditions for:
• System inefficiency
• Pump or valve failure
• Bacterial growth, including Legionella
⸻
What is Legionella and Why is it Dangerous?
Legionella is a type of bacteria that thrives in stagnant water, especially between 20°C and 45°C.
It can cause Legionnaires’ disease, a serious form of pneumonia, when people inhale contaminated water droplets (e.g., from showers or taps).
Higher-risk situations include:
• Stored hot water systems (cylinders/tanks)
• Properties left unoccupied
• Low water usage over time
⸻
1. Run Your Boiler Regularly
Even in summer, you should:
• Turn your boiler on at least once a week
• Let it run for 10–15 minutes
This helps to:
• Keep internal components moving
• Prevent pumps and diverter valves from sticking
• Circulate fresh water through the system
⸻
2. Heat Your Water to Safe Temperatures
To prevent Legionella growth:
• Set your hot water temperature to at least 60°C (at the cylinder)
• Ensure water reaches 50°C+ at taps within 1 minute
This temperature kills harmful bacteria and keeps your system safe.
⚠️ Note: Combi boilers don’t store water, so the risk is much lower—but regular use is still recommended.
⸻
3. Avoid Letting Water Sit Stagnant
If parts of your home are not used regularly (e.g., spare bathrooms):
• Run all taps and showers once a week
• Flush toilets regularly
• Pay special attention after holidays or periods away
This prevents stagnant water buildup where bacteria can grow.
⸻
4. Check Your Timer and Settings
Many people leave heating schedules unchanged over summer.
Instead:
• Turn off central heating (radiators)
• Keep hot water active if you have a cylinder
• Adjust timers to short, regular cycles
⸻
5. Inspect for Leaks or Pressure Issues
Summer is a great time to do a quick visual check:
• Look for leaks around the boiler or pipework
• Check pressure (typically 1–1.5 bar when cold)
• Listen for unusual noises when running
Catching problems early avoids breakdowns in winter.
⸻
6. Book Your Annual Boiler Service
The best time to service your boiler is summer, not winter.
Benefits:
• Easier to get engineer availability
• Avoid peak-season costs
• Ensure your system is ready before cold weather
A professional service includes:
• Safety checks
• Cleaning components
• Efficiency testing
• Identifying early faults
⸻
7. If You’re Going Away
Before leaving your property for an extended period:
• Do not completely shut down the system if possible
• Use a timer to run the boiler occasionally
• Alternatively, run all water systems thoroughly when you return
⸻
Key Takeaways
To keep your boiler healthy and your home safe:
• Run your boiler weekly
• Maintain hot water above 60°C
• Prevent stagnant water in unused outlets
• Schedule your annual service in summer
⸻
Final Advice from a Gas Engineer
Your boiler is one of the most important systems in your home. A little attention during the summer months can prevent major breakdowns in winter and reduce health risks like Legionella.
If you’re unsure about your system setup—especially if you have a hot water cylinder—it’s always worth getting professional advice.
Gas Care Plus
Ph: 07704141410
