storage heater problems

[wheneverican]

we have a Dimplex XT18 series G and its suddenly stopped working - it goes direct to a non fused spur so there is no fuse to consider (unless there is one internal to the heater?) other heaters in the house and on the same ring main are all ok.
What should i check - i'm guessing its the thermostat but any advice greatly appeciated.
Thanks
Simon

 

[Steve]

Storage heaters are high wattage devices, it is unlikely they are all on the same "ring" or circuit. You would normally have a seperate fuse box for your heaters, with each heater on a different fuse.

 

[wheneverican]

ok, thanks, i have located the fuses- as you say one for each heater. They all looked ok nad i have checked them with a meter, tripping them in and out a few times.
However i check the voltage at the heater and being economy 7 there is no power, how do i check it is actually getting a voltage without waiting until the economy 7 hours.
Hopefully not too stupid a question!! I am a little in the dark as to how eco 7 works, there is only one power feed coming in the house, is all power bewteeen midnight and 7am charged at a reduced rate?

 

[Steve]

The power will split somewhere near your meter, and there may be a radio teleswitch or a timer that you cannot change, this activates your eco7 circuits, and switches the normal circuits to cheap rate too. Take a photo and we can show you how it works if you wish. There are different setups so its hard to explain without a photo.

Inside the heater, there may well be a thermal cutout. Basically if the heater gets too hot, there is a lead link that melts and stops the power. The link can fail without reason, but common cause of overheating is putting towels out to dry. It may also be resettable, rather than a lead link. Look for a red button (with the cover off)

I am unfamiliar with storage heaters, but it shouldn't be too hard to find. Look on the top of the unit with the cover off.

 

[Spark123]

Think they are a resettable thermal switch inside, the last dimplex one I looked at it was a roundish brown bakelite device with a white button on it mounted behind the thermostat.
If it has tripped it is a case of pressing the white button till you hear the click.
Don't forget to switch off at the wall before removing the cover!

 

[wheneverican]

Thanks for help, sorry for delay.
I have taken the back off the heater and there is a connector block direct from the live input that goes through a white ceramic type block (7mm square by 50mm long) - with a wire passing through it i guess. I have metered the wire and it measures 7.5kohms and is not a short as i expected it to be. Is this the fuse?
There is nothing on it by way of markings. I could take another heater apart to compare but its a not easy to get to and i think this is it - there are not reset switches or anything else that i can see by the control area of the heater.
Thanks
Simon

 

[Steve]

Can you take a photo and upload it?

When you post a reply, under the text input box is a link to upload pictures.

 

[wheneverican]

"fuse"

• wheneverican
• 1 Jan 2009
• 1

 

[flameport]

a white ceramic type block (7mm square by 50mm long)

That is not likely to be a fuse - more likely to be a wire wound resistor used as a thermostat accelerator.

On some heaters, the cutout is part of the main thermostat/control knob assembly.
Ultimately, there is not much else in these heaters - try tracing the wires from the input, checking for continuity at each stage. Check for continuity across the thermostat (turned to max) and also across the element(s).

 

[Spark123]

That looks like a wire wound resistor - sometimes used as an anticipator to make the thermostat operate more efficiently. Does it have any markings on the side?
7k5 ohms seems reasonable to me.

 

[wheneverican]

Nope no markings, ok will have a look a bit deeper, struggling to get the whole cover off but as you say 7.5k ohms seems like a standard resistance.

 

[Spark123]

The thermal cutout should look something like this:
http://www.storageheater.co.uk/Parts/SS5301.asp

 

[wheneverican]

That is exactly what it looks like! I pressed the white part and it clicked back into place - continuity restored

I have reassembled it all and turned it all back on - will see what its like tomorrow morning... hopefully hot.

Thank you all so much for your help with this.
Simon