20jun dont buy this heater hero
Research report
25 June 2020

Don't buy this Kmart electric heater

Oil-column heaters are found in many Kiwi homes, but they aren’t all created equal – some are downright rubbish.

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R K S.
01 Jul 2020
Power drawn

Perhaps that particular heater was faulty? Although, the member review by Gavin S. says "was this heater actually rated at a lower power output than specified on the data label?", so the problem may be more widespread.
Measurement of the instantaneous load over the course of the 120 min test would indicate just how often it's drawing 2.4 kW, then we'd know what's really going on.

N & M B.
27 Jun 2020
Power drawn?

Is sounds like the heater was not drawing the rated 2400W, as all power consumed by resistance heaters is converted into heat and then transferred to the air. Was the power consumption measured?

Consumer staff
29 Jun 2020
Power drawn

Hi N & M B.

You are correct in assuming that. We do measure power consumption and this heater was way below the expected 4.8kWh after 120 minutes. It's a pattern we see in most oil-columns but this one was particularly low.

A simple resistance element will consume electricity at this rate, but a heater can slow down consumption with the thermostat or the built-in safety devices.

We believe that the overall diminished performance of oil-columns comes down to the fact that the upper limits for the temperature of the device itself are much lower than other heater types (probably to lessen the risk of too much pressure building inside the fins). You've probably found you can touch an oil-column when it's on its highest setting but wouldn't dream of it with another heater. Stopping the unit from getting too hot impacts the speed of heating up a room, but the room should eventually reach your set temperature.

Kind regards
James le Page - Technical writer