Head to head
Glow-worm Energy Combi 25C 25kW vs Vaillant aroTHERM plus 5kW
The Glow-worm Energy Combi 25C 25kW is a gas combi boiler, 25.7 kw hot water output. The Vaillant aroTHERM plus 5kW is a r290 monobloc air source heat pump, 5 kw heat output.
Last reviewed 13 September 2026

Specifications side by side
| Glow-worm Energy Combi 25C 25kW | Vaillant aroTHERM plus 5kW | |
|---|---|---|
| Dimensions | 700 x 390 x 280 mm | 965 x 1100 x 450 mm (H x W x D) |
| Weight | 32 kg | 128 kg (operating) |
| Hot water output | 25.7 kW | - |
| Central heating output | 18 kW | - |
| ErP class | A | - |
| Seasonal efficiency | 94% | - |
| Warranty | 7 years | - |
| Hot water flow rate | 10.4 litres per minute | - |
| Heat output | - | 5 kW |
| SCOP | - | up to 5.03 |
| Refrigerant | - | R290 (propane), low GWP |
| Sound power | - | 53 dB(A) at A7/W35, 58 dB(A) at A7/W55 |
| Max flow temperature | - | 75C |
Sources: Glow-worm Energy Combi 25C 25kW, Vaillant aroTHERM plus 5kW. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the Energy Combi 25C 25kW if...
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 aroTHERM plus 5kW if...
The smallest aroTHERM plus, sized for a well-insulated flat or small house. It uses the natural refrigerant R290 rather than an F-gas, and reaches a 75C flow temperature, which helps it work with existing radiators on a retrofit job.
Full aroTHERM plus 5kW specifications →Common questions
What is the difference between the Glow-worm Energy Combi 25C 25kW and the Vaillant aroTHERM plus 5kW?
The Glow-worm Energy Combi 25C 25kW is a gas combi boiler, 25.7 kW hot water output; the Vaillant aroTHERM plus 5kW is a r290 monobloc air source heat pump, 5 kW heat output.
GetBrent is an independent directory and is not a dealer for, nor affiliated with, either manufacturer. Model and brand names are the trademarks of their owners.
