Head to head
Glow-worm Energy Combi 25C 25kW vs Telford Tempest 300 Indirect
The Glow-worm Energy Combi 25C 25kW comes with 5 years more warranty.
Last reviewed 13 September 2026
Key differences
- Warranty: the Glow-worm Energy Combi 25C 25kW comes with 5 years more warranty.
Specifications side by side
| Glow-worm Energy Combi 25C 25kW | Telford Tempest 300 Indirect | |
|---|---|---|
| Dimensions | 700 x 390 x 280 mm | 1750 mm high x 580 mm diameter |
| Weight | 32 kg | 61 kg |
| Warranty | 7 years | Lifetime guarantee on the body with annual service, 2 year component guarantee |
| Hot water output | 25.7 kW | - |
| Central heating output | 18 kW | - |
| ErP class | A | - |
| Seasonal efficiency | 94% | - |
| Hot water flow rate | 10.4 litres per minute | - |
| Capacity | - | 300 litres |
| Material | - | 2304 duplex stainless steel |
| Relief valve setting | - | 7 bar / 90C |
| Immersion heater | - | 3kW, 240V single phase, included |
Sources: Glow-worm Energy Combi 25C 25kW, Telford Tempest 300 Indirect. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the Energy Combi 25C 25kW if...
- you want one that comes with 5 years more warranty
A gas combi boiler with 25.7 kW of hot water output, sized for a flat or small house with one bathroom. It delivers about 10.4 litres per minute of hot water, which decides how well a shower runs while a tap is on. Warranty: 7 years. Seasonal efficiency is 94%.
Full Energy Combi 25C 25kW specifications →Buy or hire the Tempest 300 Indirect if...
A 300 litre indirect cylinder for a larger household or a property with high simultaneous hot water demand, part of Telford's Tempest range. Like the smaller direct model it carries a lifetime body guarantee when serviced annually.
Full Tempest 300 Indirect specifications →Common questions
What is the difference between the Glow-worm Energy Combi 25C 25kW and the Telford Tempest 300 Indirect?
The Glow-worm Energy Combi 25C 25kW comes with 5 years more warranty. The Glow-worm Energy Combi 25C 25kW is a gas combi boiler, 25.7 kW hot water output; the Telford Tempest 300 Indirect is a indirect unvented hot water cylinder, 300 litres.
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