Help with replacing this discontinued Dimplex Programmer?

[Pcam86]

Hey everyone,

My flat has all electric panel heating and uses a Dimplex PW4 programmer that has died. It's also discontinued, i can see why as you need to be a rocket scientist to set it anyway.

As this is just a switched live switch am i right in assuming it could simply be replaced with any other range of programmer such as Nest, hive etc even though it's for electric panel heating and not gas?

 

[Avo Mk8]

Hi Karl
As I suggested in post #12, I believe the 'pilot wire' carries an encoded signal. I don't believe it's just zero or 230v depending on whether the heater should be on or not. But I have been unable to find any explanation of the pilot wire signalling protocol, so I can't back up this hunch!
Personally I don't think you can use a current programmer to activate the old Dimplex units as originally intended, but I'd be happy to be proved wrong.

 

[Moley]

Have any of you got pictures of the inside of the failed units? It's probably just a capacitor gone down. If anyone wants to send me a failed unit I'll take a look and see if they can be repaired.

 

[Avo Mk8]

The 'pilot wire' signalling protocol seems to have been a French development, specified in a GIFAM standard. I suspect finally dropped in the UK because the pilot signal seems to be referenced to the Economy 7 Neutral, giving a risk of 'borrowed neutral' problems.
After a bit of Googling I've convinced myself there's little point in trying to control a pilot wire heater from a typical on/off programmer or smart controller. At best all one can do is to switch the heater between 'comfort' and 'Eco' by applying mains to the pilot wire, unless one starts designing something with diodes!

I did find a Test House spec (in English) which has as an appendix describing the pilot wire protocol (but in French!), page 24, if anyone is interested!

https://www.lcie.fr/medias/cdc_103-13f_direct_acting_room_heaters_2018_05_english_version.pdf

So I fear anyone with Dimplex pilot wire heaters are stuck with keeping, mending or replacing the existing Dimplex 'programmer' (some models still available), or changing the heaters.

 

[Dartlec]

Have any of you got pictures of the inside of the failed units? It's probably just a capacitor gone down. If anyone wants to send me a failed unit I'll take a look and see if they can be repaired.

This is one I took at the most recent job with one - Not a great pic I'm afraid - hard to see but there is a bulge in the circled area - and it's been the same on every one I've seen (4 or 5 now) - The first one I ran into on a job last year was even clearer with a melted/burn mark in the same place.

I left the unit this pic is of on the job unfortunately and fairly sure I binned the one I did take from a job some months back, but I'll have a rummage. If I take one out again in the future I'll keep one for you.

 

[DPG]

Wonder if transformer has overheated and the internal thermal fuse gone?

 

[Karl sullivan]

Hi Karl
As I suggested in post #12, I believe the 'pilot wire' carries an encoded signal. I don't believe it's just zero or 230v depending on whether the heater should be on or not. But I have been unable to find any explanation of the pilot wire signalling protocol, so I can't back up this hunch!
Personally I don't think you can use a current programmer to activate the old Dimplex units as originally intended, but I'd be happy to be proved wrong.

Ok thanks for your help!

 

[Moley]

Doesn't look like RS or Farnell stock that Tx. There's a couple on Ebay. Cheapest is £11.99 & 99p P&P. No doubt there's an equivalent by a different make. I'll have a look. I was expecting a swollen or exploded cap.

 

[Avo Mk8]

Doesn't look like RS or Farnell stock that Tx. There's a couple on Ebay. Cheapest is £11.99 & 99p P&P. No doubt there's an equivalent by a different make. I'll have a look. I was expecting a swollen or exploded cap.

That transformer claims to be "short circuit proof"!

MYRRA Transformers Core: EI30 Short-Circuit Proof Output: 0,6VA, 1VA Input Voltage: 230V

Something else might be causing the problem?
Resistor bottom left of picture, half illuminated, looks like its been running warm, but again that may still be OK.
If the date code label means 2015, maybe slightly early for cap problems?

 

[Moley]

My wife claims to be attractive but.....?
I've seen caps younger than that die but usually when in a hot enclosure. That board doesn't look like it's been hot. It would be nice to get hold of one to have a probe about.

 

[freddo]

I'd definitely test the transformer before attempting to replace it, in case the defect is simply cosmetic. As mentioned the 2 electrolytics are also well worth testing. It's nice to see a real transformer instead of a tacky capacitive dropper.

 

[Mattsand]

Hi, what is best to replace the old dimplex programmer, to manage how water timings?The heaters in the rooms can be switched on/ off manually so dont need to program these.