Regular (Conventional) Boiler vs System Boiler
Compare these two popular boiler types to find which suits your home best
Regular (Conventional) Boiler
Traditional boiler requiring both a hot water cylinder and cold water storage tank.
System Boiler
Boiler that works with a separate hot water cylinder, ideal for homes with multiple bathrooms.
Key Statistics
Advantages Comparison
Regular (Conventional) Boiler Advantages
Works with low water pressure
Ideal for areas with poor mains water pressure as it uses gravity feed.
Simultaneous hot water to many taps
Can supply multiple bathrooms at once from the stored hot water.
Compatible with older systems
Works with existing pipework and radiators in older properties.
Immersion heater backup
Hot water cylinder can have an immersion heater as emergency backup.
High hot water volume
Large cylinder can store significant amounts of hot water for high demand.
System Boiler Advantages
Multiple taps simultaneously
Can supply hot water to multiple outlets at the same time without pressure drop.
Compatible with solar panels
Works well with solar thermal systems for added efficiency.
Constant hot water supply
Cylinder stores hot water, ensuring supply during high demand periods.
Good for larger homes
Ideal for properties with 3+ bedrooms and multiple bathrooms.
More space than Regular
Doesn't require a cold water tank in the loft, saving some space.
Reliable performance
Proven technology with consistent hot water delivery.
Disadvantages Comparison
Regular (Conventional) Boiler Disadvantages
Takes up most space
Requires both cylinder and cold water tank in loft.
Higher installation costs
Most complex system to install with most components.
Heat loss from cylinder and tank
More heat lost from stored water reduces efficiency.
Risk of freezing pipes
Cold water tank in loft vulnerable in very cold weather.
Longer heat-up time
Takes longer to heat water compared to modern systems.
More maintenance points
More components means more potential failure points.
System Boiler Disadvantages
Requires cylinder space
Need room for hot water cylinder, usually in airing cupboard.
Can run out of hot water
Once cylinder empties, need to wait for it to reheat.
Heat loss from cylinder
Stored hot water loses heat over time, slightly less efficient.
More complex installation
Costs more to install than combi boiler due to additional components.
Initial recovery time
Takes time to initially heat up full cylinder after installation.
Space Requirements Comparison
Regular (Conventional) Boiler
Boiler unit
Required800mm H x 600mm W x 400mm D
Hot water cylinder
Required1600mm H x 500mm diameter
Cold water tank
Required900mm H x 600mm W x 400mm D
System Boiler
Boiler unit
Required700mm H x 400mm W x 300mm D
Hot water cylinder
Required1500mm H x 450mm diameter
Annual Running Costs Comparison
| Property Size | Regular (Conventional) Boiler | System Boiler | Difference |
|---|---|---|---|
| Small (1-2 bed) | £1120 | £1030 | £90(System Boiler cheaper) |
| Medium (3-4 bed) | £1645 | £1505 | £140(System Boiler cheaper) |
| Large (4+ bed) | £2170 | £1980 | £190(System Boiler cheaper) |
Which Should You Choose?
Choose Regular (Conventional) Boiler If...
✓ Best suited for:
Older properties with existing conventional systems, large homes with very high hot water demand, properties with multiple bathrooms, areas with poor or unreliable mains water pressure, homes with traditional pipework
✗ Not suitable for:
Modern homes, properties with limited loft space, flats, homes where space is limited, properties with good mains water pressure where modern alternatives are more efficient
Choose System Boiler If...
✓ Best suited for:
Medium to large homes (3-5 bedrooms) with 2+ bathrooms, properties with multiple family members, homes requiring simultaneous hot water to several outlets, properties suitable for solar thermal panels
✗ Not suitable for:
Small flats or homes with limited space for a cylinder, properties with single bathroom and low hot water usage, homes where space is at an absolute premium
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