Neff Warming drawer failures

philip collins

Novice Member
Here is the snubber fitted on the back of the 4 way connector. The resistor on the right is not part of the snubber but replaces a 220 ohm resistor that I damaged when I previously connected the snubber to wrong relay. (oops) Nevertheless all working OK now. See my sketches of the power supply and the Tray switching and sensing. The presence of the tray (sensed when the relay connects to the N/O 5V reference) reduces the voltage to the Op-amp input and tells the uC that the tray is present and this voltage is also dependent on the resistance of the tray. Calibration should be required on a new PCB module to match the software power control to the tray. - Thanks to Ian Scot seen elsewhere in this thread for pointing this out.
Calibration is not required if you are only changing the relay on the PCB and fitting the snubber.

Any comments welcome as usual
 

Attachments

philip collins

Novice Member
On reflection, the capacitor in the snubber should be rated at >2Kv to make sure that it survives the back emf from the heater tray. I have not measured it so I am guessing. maybe I will get a 'scope on it next time I take it out.
 

altom2310

Novice Member
Can some one help. I have a Neff Warming drawer N21H40N3GB With the good old flashing light. I have already taken the whole module out and located the one half of the kettle plug no problem! However I now need to get to the back of the drawer unit Therefore I need to get the actual drawer unit off the sliders. I have done this on other equipment previously but hands up I have no idea on this unit! I have tried to take the four Screws retaining the whole slider unit off but cannot get it out of the front orifice. Is there something I have missed?

any help please. Many thanks
 

Boiler10

Standard Member
It's just the two torx screws inside the draw unit on the top at the front. It is held by clips at the back so remove screws and pull it forward. Take care clips are ingaged when you put it back. Hope that helps.
 

altom2310

Novice Member
It's just the two torx screws inside the draw unit on the top at the front. It is held by clips at the back so remove screws and pull it forward. Take care clips are ingaged when you put it back. Hope that helps.
Yes of course!! What is wrong with me today. Too much lockdown!! Right in front of my eyes!! Thank you so much for a super reply Boiler10 and such a quick reply. As in Saying it in Welsh Diolch yn Fawr
 

philip collins

Novice Member
Hi Altom,
My drawer has failed twice now and it has been the relay that has failed on both occasions. Although it may well be the kettle connector that has failed, dont assume that it is. It is not expensive and produces exactly the same fault behaviour as the relay so it makes sense to replace it anyway. You can test the relay contact resistance if you have an ohmmeter. Anything over 0.3/0.5 ohms is too high. See circuitry of the relay configuration in my earlier post.

Good luck! Let us know how you get on.
 

altom2310

Novice Member
Hi Altom,
My drawer has failed twice now and it has been the relay that has failed on both occasions. Although it may well be the kettle connector that has failed, dont assume that it is. It is not expensive and produces exactly the same fault behaviour as the relay so it makes sense to replace it anyway. You can test the relay contact resistance if you have an ohmmeter. Anything over 0.3/0.5 ohms is too high. See circuitry of the relay configuration in my earlier post.

Good luck! Let us know how you get on.
Good Morning Phillip and all
Thanks for your message Tested the coupling. That seems ok. However testing the resistance of the warm drawer it’s self Gave an open circuit result! Just to confirm I connected the warming drawer basin directly to a 240v supply and there was no heating on the element! So conclusion. I will now have to fork out £220 for a new Basin. I suppose better than a new one at £410 As has been highlighted on this forum drawer only 5 years old What Reliability!! Will keep you informed. Sorry should have asked this question earlier Is there a way of repairing the actual Basin drawer element? Access would be to remove the rivets. Could it be the wire connector to the element?? Anyone tried this. Thanks
 

philip collins

Novice Member
Hi Altom,
I never tried to repair one but its worth trying-nothing to lose. I would be interested to see some photos of your 'teardown' . As you probanly know, its often the connections and wiring that fail rather than the heating element itself. if its the element, I dont know what the construction is but if its a ceramic type it could be difficult. what about buying a non working tray on ebay ?
good luck . kerp in touch
Phil
 

expat pirate

Novice Member
Hi guys, I am not an electrician but can change a plug or rewire something by following the original. I have a 29cm deep NEFF warming drawer with the dreaded flashing red light problem.

I have received the NEFF 00612218 power coupling, have removed the sliding drawer and the 2 screws at the top of the shiny cover at the rear of the unit. However, I cannot take this cover off. There are 3 metal tabs along the bottom edge of the cover which I cannot release to remove the cover. They appear to enter the unit at 90 degrees but do not come out. I don’t want to bend the cover. How can I remove this cover? Thanks.
 

philip collins

Novice Member
Hi Ex Pat,

I have the smaller drawer and the rear cover come off with no need to bend anything. I am sure that it will come off. Can you see that you have removed all of the screws? If so , the tabs sometimes are 'joggled' and the cover may need to be gently moved through 90deg before they will slide out.

Happy to comment further if you post a picture. Good luck with the fix.
My WD is now performing perfectly for some weeks now.

b. regds Phil
 

Boiler10

Standard Member
Hi Ex Pat,

I have the smaller drawer and the rear cover come off with no need to bend anything. I am sure that it will come off. Can you see that you have removed all of the screws? If so , the tabs sometimes are 'joggled' and the cover may need to be gently moved through 90deg before they will slide out.

Happy to comment further if you post a picture. Good luck with the fix.
My WD is now performing perfectly for some weeks now.

b. regds Phil
Hi ex Pat,

I don't remember this being difficult or complicated so if the screws are out it is probably just a tight fit. I'd give it a gentle tap with a number 3 hammer! Having changed this part myself with no joy, I won't be surprised if it turns out to be the relay on the pcb at fault.
 

Nick0207

Standard Member
From memory I think the cover has to be slid down (or up) to release it from the clips. No need to bend anything. PLEASE NOTE though, I think my much earlier diagnosis about the kettle connector problem causing the flashing red light is not correct. It seems it is a relay in the power control module that is the problem but that giving it a mechanical shock (by removing the unit and changing the kettle connector) will make it work again albeit temporarily. My drawer is now failing again regularly but I hit the panel by the control knob with a wooden spoon (with it turned off) and it works. I have a replacement relay ready to fit but haven't yet worked up the motivation to do i as the spoon is easier....
 

ZHL

Novice Member
Hi, I just joined this forum because I am trying to fix my warming drawer. Admittedly, it says Bosch on the front, but earlier posts indicate that Neff, Bosch and Siemens are really all the same, so please excuse the intrusion.

The initial problem was that the level selector switch on the power module mechanically disintegrated. I ordered a new module that looks slightly different, but presumably just an update to the nine-year old one. (I was assured that it was compatible with my model - Bosch HSC140P51B/07). Now, I have had the opposite problem to the one many of you have reported - the heating element in the tray stays powered-on continuously and reaches temperatures more than 110C (the top of my RS heat sensitive strips).

So, I have sent the new one back for a refund since I got the last one the supplier had in stock. I am now stuck without a working power module.

I have two questions in the hope that you experts can help.

First, how equivalent are the various modules offered for sale under Neff and Siemens brandnames? I have seen photos of ones that look exactly the same, but are there any electronic differences?

Secondly, I goofed in that I took my unit apart too hastily, not taking photos before pulling the connectors and I have now lost track! I assume that the incoming mains wires have the same colour code as my oven - black for line and blue for neutral - I hope this is correct. The four-way connector at the bottom of the power module obviously can go on only one way, BUT there is a two-way at the top with one black wire in one pole and two blue in the other pole. Which way round should it go?

Looking forward to guidance and some reassurance!

Best regards.
 

Boiler10

Standard Member
Hi ZJL, my unit is 5 years old and is a Siemens model. Everything I have read here mainly regarding the NEF models seems to be the same as my unit. In this thread someone mentioned a calibration procedure for new boards but that was after my repair and as I'd only changed the relay I'd guess not necessary for me. Before I removed the connectors I'd noticed they didn't appear to be polarised so I wrote UP on them and took a picture, attached hope it is of use. Although I took the unit out to diagnose the problem I found, correctly, that you can get the board back in from the front. Hence the angle of the picture showing the connectors. EXTREME caution here as the board has mains voltage so I made sure the wall switch was off and pulled the circuit breaker as well. I'll also post the picture of the repaired board so you can compare. Good luck.
20190923_165744.jpg
20190923_165555.jpg
20190923_165530.jpg
 

ZHL

Novice Member
Boiler10,
Thanks for the prompt reply.

I too had to experiment to get the power module board out. My first attempt had me removing the fan heater panel, hence unplugging the main input. Not the way to get at the power module, as evidenced by a nasty gash in the side of my hand!

I then found that taking the drawer out and accessing from the front was the way to do it, as you say.

Your photo is reassuring but not quite definitive. I think your "up" on the two-way connector means that the single black wire goes nearer to the side of the relay. Is that correct?

If so, I did install my new module correctly and the failure is not my fault (phew!). The explanation now seems to be that the relays stuck from new with power always applied to the tray heater. However, I did hear clicking every twenty seconds or so.

The new module did have the complicated calibration procedure which I managed to follow, but setting it to the lowest offset made no difference to the overheating.

Best regards.
 

Boiler10

Standard Member
Hi ZHL, OK just pulled the cover off and took the picture attached. Looking at all the pictures you can probably work it out. But the two blue wires on the top connector on my unit are nearest the up arrow. Hope that helps..
20200724_195105.jpg
 

ZHL

Novice Member
Boiler10,
Wow! Thanks for putting in the extra effort to help me.
Yes, that's the answer: black wire nearer to the relay, blue wires towards the centre of the tray.

I now need to choose an alternative supplier to get a new power module. Your Siemens board looks like the Bosch-branded board I just sent back.

Is it safe to assume a Neff-branded board is also the same electronically if it looks the same?

Does anybody else out there have a view on this point?

Best regards.
 

Boiler10

Standard Member
Tricky question, my Siemens board has a blue LED so that is a difference to the NEF units but looking at other pictures on this thread they look very similar. The model number for my unit is in an early post #13 I think. Others on here have looked at the circuit more closely.
 

Urbanfox2

Novice Member
Hi all
Ihave the 290mm warming drawer and the drawer won't close. I took out the latch which seems to be working fine its like the drawer pin isn't going in far enough to catch and stays open...any suggestions this latch is 35pound
I have had the same problem. The small white plastic hex seems to be an adjuster. I turned this and got the drawer to latch again. didn't need to take it out as it can be reached from below when you pull the drawer case out some way.
Here are the instalation instructions showing the adjuster at 2.
 
Last edited:

philip collins

Novice Member
Hi, yes the adjustment is via the hex adjuster under the drawer that can be turned with an allen key. Make sure that it is adjusted so that the drawer latches as close to the main body as possible. If the drawer is too far out when it is closed, the power (kettle) connector at the back of the drawer will not be fully inserted and fail due to the poor connection between the two parts. BTW, the clicking of the relay every 20 seconds or so is the drawer control relay making and breaking the mains power to the tray. This is the way that the control pcb regulates the drawer temperature. If your drawer is getting very hot , it could be that the power from the control relay to the drawer is not cycling on and off.

Hope this helps.
Phil C
 

BobHelston

Novice Member
Neff sell a warming drawer to match their hide and slide oven range. They are surprisingly useful and work well (for a time). The model is Neff N17HH11NOB (140mm high) and the larger N17HH20NOB (290mm high).
Mine failed after 3 years and was going to cost probably around £150+ to repair by Neff (£99 labour/call out plus parts on top). There seem to be many owners who suffer from a similar failure, Neff's own website does not make good reading , have a look N17HH11N0B

The problem with mine was that the red light kept flashing when the drawer was closed and only a small area of the hot plate (rear right hand side) got at all warm (by the fan heater which is in the side of the unit). The fault turned out to be with the power connector at the rear of the pull out drawer which was failing. It's basically a kettle connector for cordless kettles. The control module will not connect power to the drawer unless it detects it's closed. When the connector begins to fail the hot plate will not get warm as the power controller thinks the drawer is open.

Replacements are available from here 00612218 or ebay Bosch Neff Siemens Coupling 612218 | eBay

Relatively easy to fit but do not attempt unless you are competent. The whole device has to be removed as both parts of the power connector need replacing. The drawer itself is easy to remove, just remove the two screws from inside the drawer (one each side) and the drawer can be lifted out.
On the main unit the connector is fitted inside the panel on the rear (two screws).
bl
Neff sell a warming drawer to match their hide and slide oven range. They are surprisingly useful and work well (for a time). The model is Neff N17HH11NOB (140mm high) and the larger N17HH20NOB (290mm high).
Mine failed after 3 years and was going to cost probably around £150+ to repair by Neff (£99 labour/call out plus parts on top). There seem to be many owners who suffer from a similar failure, Neff's own website does not make good reading , have a look N17HH11N0B

The problem with mine was that the red light kept flashing when the drawer was closed and only a small area of the hot plate (rear right hand side) got at all warm (by the fan heater which is in the side of the unit). The fault turned out to be with the power connector at the rear of the pull out drawer which was failing. It's basically a kettle connector for cordless kettles. The control module will not connect power to the drawer unless it detects it's closed. When the connector begins to fail the hot plate will not get warm as the power controller thinks the drawer is open.

Replacements are available from here 00612218 or ebay Bosch Neff Siemens Coupling 612218 | eBay

Relatively easy to fit but do not attempt unless you are competent. The whole device has to be removed as both parts of the power connector need replacing. The drawer itself is easy to remove, just remove the two screws from inside the drawer (one each side) and the drawer can be lifted out.
On the main unit the connector is fitted inside the panel on the rear (two screws).
 

BobHelston

Novice Member
I am having trouble knowing the best way removing the unit to get at the other part of the connector.
I know it is held by screws at the front but can't get the covers of.
 

philip collins

Novice Member
Hello Bob,
before you proceed, please understand that the connector may not be the cause of the failure. I am assuming that you have the dreaded flashing light and no heat to the tray. I had exactly the same problem but it was caused by a relay on the control board. See other posts in this thread.
If you are adept with a soldering iron, it is not a straightforward process to remove the old relay. See other posts for guidance. Note that the relay life is often less than 2 years unless you fit a suitable 'snubber' (see my earlier post in this thread.)

Kettle Connector
To access the other part of the connector, you will need to remove the drawer. Usually this means first removing the oven above as there is often no supporting plate for the oven. The upper oven uses the warming drawer as a support. You will need to remove screws holding the rear cover and this will expose the other connector part. The connector is housed in in a plastic holder that fits into a circular cut-out in the rear panel. The plastic connector holder must be rotated to release it from the circular slot. In order to release it, you will need to lift up the plastic lugs that lock the holder into place while you rotate the holder . Once the holder is out, you can remove and re-fit the new connector.

Hope this helps. Let us know how you get on.
 

lethbridge

Novice Member
Hi all, another one here - I have a 5 year old N21H40N3GB - mine is the element as it is open circuit. Can't find a replacement online or on eBay and suspect if I do it won't be far short of the price of a whole new unit (around £300 for N1AHA01NOB). All ears if anyone has sourced the tray/bowl/basin (however you refer to it!) online at a reasonable price? My concern with a new one is just how well it will match the other appliances (all matching 2015 models). I'm hoping I may be able to fit the existing front to the new one or even get away with swapping the tray out to save removing the old chassis and at least I'll have some spares for when the rest of it fails as it doesn't sound like much has changed over 5 years.

Before I do order one I will strip down the old tray just in case a wire has dropped off the element itself but I'm not hopeful...
 

philip collins

Novice Member
Hi all, another one here - I have a 5 year old N21H40N3GB - mine is the element as it is open circuit. Can't find a replacement online or on eBay and suspect if I do it won't be far short of the price of a whole new unit (around £300 for N1AHA01NOB). All ears if anyone has sourced the tray/bowl/basin (however you refer to it!) online at a reasonable price? My concern with a new one is just how well it will match the other appliances (all matching 2015 models). I'm hoping I may be able to fit the existing front to the new one or even get away with swapping the tray out to save removing the old chassis and at least I'll have some spares for when the rest of it fails as it doesn't sound like much has changed over 5 years.

Before I do order one I will strip down the old tray just in case a wire has dropped off the element itself but I'm not hopeful...
Hi Lethbridge,

Please let us know what you find in the tray. It would be good to understand what the failure is so that someone could possibly come up with a fix. Good luck,
Phil C
 

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