Dimplex ML3TSTIE7 3kW Convector Heater review: running cost and verdict
The 3 kW version: electronic thermostat accurate to about 1 °C, frost protection and a 7-day timer with four schedules a day, for large or poorly insulated rooms.
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The good
- 3 kW for large rooms
- Electronic thermostat and 7-day timer
- Frost protection
The not so good
- 3 kW costs a lot per hour at full power
- Few reviews checked
How much does it cost to run?
One hour at full power (3,000 W)
at 26.32p/kWh
A month of typical use
5 hours a day on thermostat
Ofgem price cap, Direct Debit, national average (1 October to 31 December 2026). Watt for watt, every electric heater costs the same to run. What makes the Dimplex ML3TSTIE7 3kW Convector Heater cheaper or dearer is its size and its controls: digital thermostat, weekly schedule. More in which electric heater is cheapest to run.
Specifications
| Type | Convector heater |
|---|---|
| Power | 3,000 W |
| Room size | about 30 m² (323 sq ft) |
| Controls | Digital thermostat, weekly schedule |
| Oscillation | No |
| Tip-over protection | Not stated |
| Splash protection | No |
| Noise | Silent (no fan) |
| Amazon ASIN | B09WJFYXY7 |
| Source of specs | Amazon.co.uk listing (ML3TSTIE7, 7-day timer) |
Frequently asked questions
How much does the Dimplex ML3TSTIE7 3kW Convector Heater cost to run?
At full power it uses 3.00 kWh an hour: about 79.0p at the Ofgem price cap (26.32p/kWh). Typical use (5 hours a day on thermostat) comes to around £71.06 a month.
What size room will the Dimplex ML3TSTIE7 3kW Convector Heater heat?
About 30 m² (323 sq ft) in a reasonably insulated home. For a draughty room or an old house, go one size up.
Can I leave the Dimplex ML3TSTIE7 3kW Convector Heater on overnight?
It is designed for long periods: use the thermostat on a low setting, keep it away from curtains and bedding, and plug it straight into the wall.
Can I use the Dimplex ML3TSTIE7 3kW Convector Heater in a bathroom?
No: it has no splash protection. In a bathroom use only heaters rated IP24 or higher, fitted outside the wet zones.
Alternatives
Dreo Atom 316 Ceramic Heater 1500W
- Fan heater · 1,500 W
- One of the most-reviewed ceramic heaters on Amazon UK: quiet (34 dB), digital thermostat, 12-hour timer and remote. Warms a bedroom or home office in minutes.
- Costs 39.5p an hour at full power.
Dreo 2000W Oscillating Ceramic Heater
- Fan heater · 2,000 W
- 2 kW with 70° oscillation to spread the heat, a thermostat, 12-hour timer and remote. Enough to take the chill off a living room quickly.
- Costs 52.6p an hour at full power.
Dreo Solaris Slim H3S Smart Heater 2000W
- Fan heater · 2,000 W
- Slim 2 kW heater you can switch on from your phone before you get home, with thermostat, oscillation, timer and remote.
- Costs 52.6p an hour at full power.
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