[Mark Goddard]

The plug overheated and was totally destroyed, the RCD was also badly damaged. This is the second time in 2 years, anyone had the same experience?
I normally get the temperature up to 60 degrees and switch it off, but there are occasions when I forget.
At 240v you're  in the margins (3000 / 240v =12.5A) if the domestic supply is 230v then you pulling 13.04A

Cheers
Mark

[Dennis]

Theoretically the lowest voltage could be 216.2 volts (230v +10%/-6%) which means it could draw 13.9 amps and if the element is on its upper limit even more so run that for 2 or 3 hours and that plug will suffer.

[JandS]

I've had my Ninja  7 years now and heater still going strong...if you forget to switch it off it shouldn't matter it's on a thermostat.

[Paul Clapham]

I've had this happen on my Airflex , but it turned out to be a loose wire in the plug, very scary when it happens!

[CleanerCarpets]

as above post - why do you need to turn it off? shouldnt the thermostat be doing that?

[Mark Goddard]

J&S
Yes the thermostat shuts off when it reaches the required temperature, however if the machine is outside the heater is kicking in continually. If the 3KW element is on for a couple of hours or so, there is a potential for the plug to seriously overheat especially if it's drawing in excess of 13 Amps.
This could also impact on the socket & internal wiring.

[john martin]

J&S
Yes the thermostat shuts off when it reaches the required temperature, however if the machine is outside the heater is kicking in continually. If the 3KW element is on for a couple of hours or so, there is a potential for the plug to seriously overheat especially if it's drawing in excess of 13 Amps.
This could also impact on the socket & internal wiring.

I would almost be sure this caused by resistance heating .   Cause could be a fault in the heating system , wiring , or plug oxide issues  .
The fuse should be capable of handling the heaters current and more if resistance is normal . 
You said the RCD was damaged ?  i presume u mean an external device of your own that u plugged into ... not the house main RCD ?
I would start with a fresh plug ... try it again . See if it works ..

[JandS]

Even doing a full house that takes maybe 3.5 hours my heater will be on for no more than about  20 mins.
Hot water in,  heat up to max , say 10 minutes whilst still prepping, turn it off and use it to extract...it stays hot for ages in the tank.
Maybe half fill again and heat or re heat if plenty left in for 10 mins whilst prepping ground floor switch off and extract.
Why do you need to keep it on for 3 hours anyway.

[Mark Goddard]

JandS
The  answer to your question is in my initial post.

[dutchman]

I have had the exact same problem with an enforcer. I have bought a new heater cable as I have changed the plug but the new one did the same. It actually melted the plug into the socket.  Had to replace customers socket . I will get someone to sit the new cable and see if that fixes it.

[JandS]

Use same socket for power and heater that way you have to take one out to plug other in or if a double you will see you have heater still on and switch off.