Economy 7 - dead heater?

[Jaiyan]

Hi all,

First post and domestically limited, so go easy I have a problem for which I'm not sure how to best resolve, and I've not found anything searching the forum.

I live in a 'one-up-one-down' flat, with heating supplied through three Economy 7 wall-mounted heaters. All has been fine for the 5 years that I've lived here; however last Saturday morning I woke up to find my living room heater had not heated overnight.

Hoping (vainly) that it was just a one off, I adjusted the settings to a different temperature for the next night's heating; however, sure enough, the next morning the heater was still stone cold. At this point, I switched it off at the wall, and started to find any information I could

The other two heaters (in the bedroom and hallway) are heating happily as normal - so I'm pretty sure it's not a central problem. Also, there was no sign of degradation from the living room heater leading up to it failing (i.e. it didn't pump out less and less heat over the previous week).

Does anyone have any experience of this? Barring having the ability to wire a 3-pin plug and change fuses, I'm not knowledgeable with electrical problem-solving.

Could it be a fuse in the wall-mounted switch that's died? Or will I likely have to buy a whole new heater and get it fitted? I'm keen to get it sorted asap, what with more snow being forecast next week

Here's a picture of the switch and heater for what it's worth - in case there are numerous types of switch
http://www.jaiyan.com/heater.jpg

Thanks for any help,

Lloyd

 

[Lectrician]

First thing I would do is check the thermal cut out.

Take the cover off - and look for a small disc about an inch across. It will have a small button in the centre, and two terminals either side. Press the button. If you feel a 'click', the cut out had 'tripped'.

These cut out due to excess heat. This can be caused by clothing laid on the heater etc, or can be caused due to the thermostat inside the heater not turning off when it should. Click it in, and try it for a couple nights. If it trips again, you need to look at the thermostat.




It could also be a supply problem on that one circuit. The fuse would be in the consumer unit, not in the switch face plate. Could be the fuse, damaged cable, faulty switch etc etc.

 

[Jaiyan]

Thanks very much for your help! Very informative!

I can't see how to remove the cover on the heater after having a quick look. The only cover I can see that's easy to access is the heater dials on top of the heater. Would it be a metal panel that I could physically have to lever off with a tool? Or should the cover be obvious and easily accessible?
I'll have a more detailed look and get back to you with my results.

Hopefully it's just tripped, but I never overheat it or cover it, so we'll see. Thanks!

 

[BJS_Spark]

I agree 100% with Lectrician but have found several of these heaters in the past with lead thermal fuses. They are constructed as a barrel of lead with copper wires out of each end and are fitted under the cover of the heater as suggested. When the heater over-temps usually due to being covered the lead melts and the go open circuit.

 

[BJS_Spark]

There shoud be three small screws on the front at the bottom and one either side at the top which hold the cover on. You have to pull the knobs off the controls and with the screws removed the cover comes forward at the bottom and can be lifted up and clear. Isolate the supply before removing the cover and check the fuse at the consumer unit first.

 

[Jaiyan]

Thanks for joining in BJS_Spark

I believe I've found the three screws under the heater and the two at the top-back, so that's a good start to access the guts of this heater

It's also a relief that the fuse is in the consumer unit, not the wall face plate (I didn't fancy taking off wall plates ).
It looks like a 16amp fuse for the heater, so at least I know what I need.

Thanks very much though guys - you're lifesavers. I'll give it a crack on saturday morning and let you know if I'm still stuck after doing these tests

All the best.

Lloyd

 

[JohnD]

Just to check - have you examined the fuse in the consumer unit? It'll probably have a 16 or 15Amp blue fuse carrier for each heater, and with luck they'll be labelled to say which fuse is which room. Best of all, you'll have an MCB that you can reset with a button or switch, whose position wil show if it's tripped.

Some will contain a cartridge fuse that you'll have to test, or swap for the immersion heater to see if it's good. Some old ones contain fusewire that we don't much like.

You must switch off the MCB, or take the fuse out of the consumer unit and put it in your pocket* before you do anything to the switch, connection or heater. Best not to trust switches, especially on an appliance that has unexpectedly stopped working.





*so that no-one else can put it back in.

edited to say, sorry, already covered

 

[Jaiyan]

Hi guys,

Thanks for all your tips. I had a look around today and this is how I got on:

I started by taking a look at my consumer unit to change the fuse. I found the individual switch for the heater and switched it off; however when it came to removing the fuse I got a little stuck (I'm in danger of looking very silly here I think ) as I realised I'd never had to do it before from a consumer unit.

Here's a picture of my heating consumer unit. The switched that's set to 'OFF' - which I turned off myself (it hadn't tripped) - is the heater in question. http://www.jaiyan.com/fuse.jpg

I presumed that the fuse was located in the segment behind the switch for that heater, and that I'd simply have to remove the switch segment to get to the fuse once I'd turned off the main switch; however it seemed stuck fast when I tried to remove it. I tried to pull the others, but they didn't move either.

Rather than continue, I thought I'd better check here first. Am I doing this right? Or am I barking up the wrong tree as to getting at the fuse? I was planning to swap the fuse with one of the other heaters tonight; but accessing the fuse is proving troublesome



Anyway, next I moved on to the heater itself to look for the trip switch. I removed the cover as suggested; however I couldn't locate the described trip switch.

Here are some pictures of the electrics on the top and bottom of the heater:

http://www.jaiyan.com/top.jpg
http://www.jaiyan.com/bottom.jpg

The little red dot on the top picture looked to be an LED, while the yellow spot is a sticker. Sorry for the poor quality photos - I'll try to get better ones if no-one else can find the trip-switch from them either.

I much appreciate all help given.

Thanks all.

 

[Steve]

they are mcbs - not fuses - turn it on to reset.

MCBs are unusual on storage heater installs - these installs are usually of the older sort with fuses. Yours seems quite a modern one.

dont pull on the MCBs, because they are fixed under the surrounding cover. They dont just plug in.

Yes, you do look rather silly! but never mind! mistakes are how we learn!!

 

[Jaiyan]

Ahh, I follow what you're saying about MCBs and fuses

Regarding resetting the switch, my only concern is that it didn't trip to 'OFF' itself when the heater stopped working - I set it to 'OFF' myself.
So when you say I should reset it back to 'ON', might that fix the problem, even though it didn't trip in the first place?
I hope that's what you meant, I'll give it a try


As another slant on the issue, could it be a faulty MCB? Or is it more likely to be an issue with the heater now that we've established that fuses aren't an issue?

In any case, I appreciate the help. And I'm certainly learning! I'm in my first home/flat since moving out (hence the lack of knowledge), and this is the sort of thing my Dad used to help me with before he died. Luckily there are great people and sites like this one to help me out nowadays!

Thanks.

Lloyd

 

[Lectrician]

I see the theral link has melted on your first pic.

You can see the blob of lead on the paper label where it has dripped from where it was.

You need a new one, they are available on line, or from wholesalers. They come in three colours which corresponds to 3 temperatures. You can see the two screws where the links was.

 

[Lectrician]

Excuse the crap arrows - I hate latop mouse pads!

 

[Steve]

Would the thermal link indicate another fault? Faulty thermostat? The heater must have gotten too hot at one point and melted it - this is the real problem here, surely?

 

[Jaiyan]

Lectrician: That's excellent! Thankyou. At least we know why it has died now. I did notice that the blob didn't seem to be doing anything, and wondered whether that might be a problem; but thanks for pointing it out and confirming it.

A few questions relating to it then:

i) Just to confirm my understanding, that blob of lead should have been linking the two screws, yes?

ii)And if I buy the thermal link, is it just the lead link itself that I buy, and then attach it to the screws? Or do I buy it with the screws pre-attached?

iii) Is it expensive, and would I need an electrician to fit it? Or could I just remove the screws, attach the link, and screw it back on again myself?

iv) Regarding the three coloured types, I presume that's dependent on the Kw level of my heater itself?

v) Would I have to remove the existing lead first for safety?

vi) Do you know of any websites that I could visit to order one, when I know the right colour to buy?

Sorry to bombard you with all those questions. It'd be great if it was easy enough for me to do, so I'm trying to find out as much as possible

Thank you

 

[Jaiyan]

Crafty: Thanks for pointing out that there could be an underlying reason. The heater never gets set over level 4 on either dial, so I don't ever overheat it. However, I *think* I might know why it might have melted.

I went away over Christmas, and my partner went to stay with her family a day later. Unfortunately, after telling her about these posts, she just told me that she forgot to turn the heater off from its level 4 before she left. That wouldn't be too bad in itself; however we need to have the living room door closed when we're away from the flat for the burglar alarm to work - therefore, the heat would have been trapped for a week.

On her return she said the room was very hot, but not scorching - by the sounds of it, certainly higher than level 6 anyway. I'm wondering whether that may have sufficiently melted the lead to a weak level, and the remainder has melted under a level 4 heat over the last few weeks.

I may be clutching at straws, but it's certainly sounds like the heater could have been overly hot (not to mention a potential fire risk!).