Dimplex Wfe 3Tns - Not Working

[robidoo99]

Hello

I have a Dimplex WFE 3TNS fan convector installed in my garden room.

A few months back I left the door open overnight by mistake, and since then it won't heat - it was just out of warranty when this happened.

Tested fuse, that is ok - the digital clock still works but I think that runs off a battery

When I switch main on/off rocker switch, the red light above it does not come on as it used to

Brother suggested replacing/resetting thermostat as cold temperature may have broken it

I can't post operating instructions on here as I'm new to the forum, but if you google "WFE 3TNS operating instructions" then the first result has a link to operating instructions

In the wiring diagram (fig 3) I have located the Cut out ©, which does look like a thermostat, has a little metal flap you can push across

The other part I may need to reset is Electronic Stat (D) but I'm not sure how to do that, if it is possible

Any help much appreciated, thanks

 

[ProDave]

Do you have any test equipment? multi meter etc?

 

[robidoo99]

I have got a multimeter, not used it a lot but have a rough working knowledge

 

[ProDave]

With the supply turned OFF set the meter to ohms range, and check for continuity across each thermostat.

If the over heat trip is open circuit, then try and reset it. the mechanism to do so is not always obvious, so post a picture if you can't work it out.

 

[robidoo99]

Thanks. Checked continuity across most components are couldn't find anything blown (multimeter is cheap/erratic though)

There is a chip on the circuit board which I wondered if it might have been damaged by cold weather. But there were a couple of PCs in same room which showed no ill effects

I can't see anything on the circuit board that looks resettable

The cutout looks like a standard thermostat to my untrained eye, little metal flap in the middle that I would expect moves across when too hot, breaks circuit - it is situated directly above the heat element

Pictures here:

ht tp:/ /s1330 .photobucket.c om/user/robidoo99/library/
(delete spaces in above address, forum wouldn't let me post link)

Does the cutout bit look like it could be reset somehow?

I am only doing stuff with fuseboard trip switch off at the moment

 

[robidoo99]

There is definitely power to the unit when I switch trip back on at fuseboard - little LED on the clock display marked "power" comes on

But the rocker switch to turn heating on has another LED which does not light up. I would expect that to come on whether the thermostat had cut out or not - so maybe there is a problem with the circuit board, as there is not much going on to stop that LED coming on

 

[ProDave]

Looking at the wiring diagram, virtually nothing will work if the cut out © has tripped.

That's the thing in the third picture.

It should measure pretty well 0 hms across it's two terminals. Have you checked that?

 

[robidoo99]

Yes, negligible reading there as v low resistance, so cutout not tripped by the looks (meter reads "1" when the contacts are not applied to anything)

There must be something else causing the lack of power to either LED:

1 LED is for rocker switch, should light up as long as switch is on regardless of whether heating element is engaged

1 LED is only on when room temp falls low enough to trigger the heating to start working

At the moment, they are both doing nothing. So I need to figure out where the fault lies in the circuit maybe