Broken switch on night storage heater - fixable?!

[The General]

Well, firstly I ought to say that I think it's a broken switch!

I've checked that power is getting to the switch, but when you turn the dial and it 'clicks' there is still no power output in the returning line down to the elements.
I can't see what else it could be? Open to offers though...

So,
Customer has asked me to fix it if possible.

Is it possible?
I must make it clear that I'm not an electronics engineer and I'm pretty new to the whole domestic installation game, so soldering/intricate fiddly wiring is not for me. However, if you can buy a straight drop-in replacement then I ought to be able to cope!

It's a Dimplex model XL12N if that helps.

If it's not possible the customer has got a couple of old heaters that are gathering rust in the shed, so they want me to replace it, but I'd hate to go through all that work if I can just drop a new switch into the existing one (particularly as I don't even know if the other ones work!!)

any suggestions?
thanks in advance!

 

[malcolmsanford]

And dimplex said ..................................

 

[telectrix]

probably....... it's an obsolete model, sir. no spares available, but we can supply you with a nice shiny new model for £££££££££

 

[The General]

And dimplex said ..................................

Fair point.....I'll get onto that then....

 

[UNG]

So you assume that the switch is faulty but it sounds like you didn't test it and you didn't check the full circuit out and check the over temperature device hasn't operated then.

I sense that phrase is going to be used soon

 

[The General]

So you assume that the switch is faulty but it sounds like you didn't test it and you didn't check the full circuit out and check the over temperature device hasn't operated then.

I sense that phrase is going to be used soon

hence why I'm seeking advice from more experienced people on a forum like this!

over temperature device? - pray tell me more......

I checked that power was coming in up to the incoming terminal of switch, but once operated there was no output on the return terminal back to the element - so perhaps naively I have assumed that the switch is dodgy?

Dimplex were actually very helpful in providing part number etc, so a new Thermostat & Cut-out assembly can be on it's way to me easily enough if that is the problem.

So, enlighten me:
How to actually 'test' the switch itself? I can see the mechanical operation is working and the contacts are being made, so what else do I need to look for? genuinely, I'm all ears! :bigear:

 

[ringer]

Continuity - isolate the supply, then check continuity through the switch. I take it you have test equipment?

 

[The General]

Continuity - isolate the supply, then check continuity through the switch. I take it you have test equipment?

yup.

But surely if there was continuity through the switch then there'd be a voltage at the outgoing terminal?!?

unless you mean measuring continuity across two other points - I'd assumed you meant across the incoming/outgoings terminals...

 

[ringer]

I am suggesting that you do a dead test on the switch to check the resistance between the incoming terminal and the outgoing terminal on the switch. So far you have only done a live test for voltage. Check for resistance and operate the switch to confirm the switch is actually switching the circuit on/off.

This is pretty rudimentary stuff. Are you sure that you are competent enough to be working as an electrician?

 

[The General]

I am suggesting that you do a dead test on the switch to check the resistance between the incoming terminal and the outgoing terminal on the switch. So far you have only done a live test for voltage. Check for resistance and operate the switch to confirm the switch is actually switching the circuit on/off.

This is pretty rudimentary stuff. Are you sure that you are competent enough to be working as an electrician?

Perhaps not, but at least I'm smart enough to know when to ask for help rather than just bodging a job and hoping for the best!
The only way to learn is to ask questions, and it is becoming clearer every day that the course I did had quite a lot of gaps in it.....
I'm doing my best to plug those gaps as quickly as possible, but learning on the job is part of that process!


anyway, back to the matter in hand..

I'm still not sure that I understand why measuring the resistance across the switch will tell me anything different to what I already know?!
Surely if there was even a hint of continuity then when a voltage is applied there would be some sort of output?
Feel free to tell me to go back to school, but my understanding is that even if there is a high resistance there'd be some sort of current?

I just don't see what measuring the continuity across the switch is going to tell me that I don't already know? The circuit is not being completed within the switch, because if it was then there'd be an outgoing voltage....

unless of course I've got completely the wrong end of the stick, which is entirely possible.

 

[UNG]

You need to do something really basic and not make assumptions

Why work live when most of the problems can be located with the appropriate test equipment when the equipment is dead

You need to understand that most heating appliances have over temperature devices fitted these can be fusible thermal links or resettable bi-metal switches that disconnect the power to the elements until they are manually reset

 

[The General]

You need to do something really basic and not make assumptions

Why work live when most of the problems can be located with the appropriate test equipment when the equipment is dead

You need to understand that most heating appliances have over temperature devices fitted these can be fusible thermal links or resettable bi-metal switches that disconnect the power to the elements until they are manually reset

Thank you.

The Dimplex website mentions a thermal cut-out, but simply says to contact Customer Service (read 'sales'!) line...

Do you know how to check if that is the problem, and if so, how to reset them?
Or do I have to go through Dimplex?

 

[malcolmsanford]

The overload is pretty straight forward it's an in line switch. They can either be manual reset or replaced.

The manual rest ones would normally have a small push button which you simply push down to reset.

You can test them again the same as nay switch with a continuity tester

 

[UNG]

Not sure from memory the heater model you have but I think the over temp cut out is located close to the charge control it's a bit awkward to get at but is easily recognised if you know what you are looking for

 

[nickblake]

its item no 4 thermal cut out

 

[The General]

its item no 4 thermal cut out

THANK YOU!
You had more luck with finding schematics than I did on the Dimplex website!
thanks again.

 

[bradder]

Element resistance of these heaters is around 20 ohms.thermal cut-out for the xl12n is slightly different to the picture but in roughly the same place .(still a manual reset)
cover screws are under the heater using 8mm spanner to remove screws
This heater should not contain asbestos

 

[mogga]

FIRST THINGS FIRST check the list in forum for heaters containing asbestos in the "old heaters rusting in the garage"

 

[The General]

FIRST THINGS FIRST check the list in forum for heaters containing asbestos in the "old heaters rusting in the garage"

already done my friend!
but thanks - I was only aware of the asbestos issue from browsing previous threads on storage heaters, so it's worth mentioning again for anyone else who happens to be browsing this one!
thanks.

 

[oldtimer]

The heater in the picture is the old model ie the high limit is detched from the control module you cannot get a spare as you need to buy a conversion unit that has the control module and high limit combined (i will ad the part No later) Also when I work on these the No1 fault is a worn or old age high limit stat No2 is a faulty 20 amp DP isolation switch due to a cheap as chips unit being used or a slack connection No3 user misuse
ie putting the washing on it overnight to dry ie big bath towel that causes the unit to trip on high temp cut out.

When I go to a job I switch off the the faulty heater at the 20 amp dp swich and measure the resistance this proves the circuit is ok right through the controls and high limit to the element plus if it is a dodgy DP switch then you have not stripped down the heater. Now if this is the case then replace the switch put it on go back to the off peak DB swiitch it off and then measure the resistance again through the MCB circuit cable dp switch and heater.

Dimplex part number XL 09045 also here is the instruction and how to do it plus a link

View attachment 9509009.pdf

Dimplex XL12N/18N/24N

 

[The General]

Wow - thanks!
That's why I ask questions on here.....
great work!

 

[Horsepig]

Actually, I've had a similar problem this week, an XLS24N model with terminals that have detached from the thermal cut out rendering the heater useless. On this model there are two cut outs side by side and having read this thread I assume that a similar solution of the repair kit will be needed. Good post

 

[oldtimer]

Happy to help all contributions welcome:yes::yes::yes:

Forgot to add remember to check the switched side of the control/high limit stat to ensure the element is ok ie 18-24 ohms