Extension lead red flags

Extension leads and temporary equipment

A plain-English checklist for extension leads, coiled reels and adaptor chains used with temporary heaters or drying kit.

Safety boundary: this guide is for early planning only. It does not inspect hidden wiring, sign off an installation or replace a competent electrician.

Quick answer

Extension leads are not a shortcut around a weak plan. Before running temporary heaters, dryers or portable AC, check the lead rating, whether the reel is fully unwound, the route, and what else is sharing the supply.

Typical example

A 2,000 W heater is about 8.7 A at 230 V. Add a dehumidifier or fan through the same lead and the current can approach the warning point for a 13 A setup, especially if the lead rating is unknown.

Red flags to remove first

Do not daisy-chain extension leads, do not run high sustained loads on a partly coiled reel, do not use a damaged lead, and do not route temporary cables through wet, crushed or high-traffic areas.

Read the label

Some cable reels show different ratings for coiled and fully unwound use. If you cannot read the rating, do not guess it is suitable for heater or drying loads.

Better planning options

Move the equipment closer to a suitable outlet, reduce what runs together, use a confirmed separate circuit, or arrange a proper temporary supply route rather than adding adaptors.

Handoff note

Send the lead rating, reel state, cable route, equipment watts and photos of visible plug/socket condition to the responsible person or supplier. The evidence capture page gives a simple checklist for this.

Equipment next step: if the load plan is realistic, compare ventilation and air movement options and keep the calculation trail with your site notes.

Run the load check