The water in your radiators might not be hot enough.
The water in your radiator needs to be over 40 °C to activate the thermostat in the radiator, there are a number of reasons why this might not be happening:
Your radiator needs bleeding, excess air build up in a radiator will stop it reaching full operating temperature. Follow our radiator bleed guide to learn more about this issue and how to solve it.
Your radiator valve might be set too low, if your radiator valve is always set to 2 or 3 then this may be stopping radiator reaching full temperature. Consider turning the valve controller up to 4 or 5, read our "How to set your radiators" guide.
The temperature that your boiler heats the water to might be too low, the best solution to this is to turn the water temperature up at your boiler.
If none of these solve the problem or you don't want to increase the temperature of your system then the Radfan might not be for you. If you've had it for less than 30 days then you will be able to return it to where you bought it for a full refund. Sadly, we can only refund units purchased through radfan.com ourselves, if you purchased from Lakeland, Amazon, Lake Renewable etc then you will need ask them for a refund as they are the only ones able to refund your payment.
Has your Radfan been on the radiator for more than 30 minutes?
It can take up to 30 minutes for the Radfan to turn on the first time as it has just spent the night in a cold delivery van and a few days or weeks in a cold warehouse. Once it is up to temperature it should start turning on within 10 minutes of the heating coming on.
Does the Radfan turn on when heated with a hair dryer?
Aim a hairdryer into the cap where the cable enters the unit, if it takes more than 30 seconds for the fans to turn on then the Radfan fails this test.
Sadly it sounds like the Radfan isn't suitable for your radiator or heating system, if you purchased it less than 30 days ago then you will be able to return it for a refund to where ever your purchased it from.
Is this the green light showing on the power supply?