Hi caffeinated friends,

I picked up a second hand ECM Giotto premium pretty cheap. My machine turns on and the lever engages the pump which pumps water through the group head but no heat. I didn't do too much diagnostic work whilst it was all together as I always intended to completely strip it and clean it.

I was searching the internet for info on this machine which found this site and this thread in particular Rocket Giotto Premium Plus won't start - Diagnostic help appreciated

I was hoping to just ask a quick question in that thread, but unfortunately it is closed.

I have pulled all the piping components and the boiler apart and it is pretty badly scaled, so those have had a first pass with descaler, I rinsed everything and will have another go in the next few days. I have always suspected it is an electrical issue or a pressurestat. So whilst I had the boiler removed and full of descaler I started continuity testing the wiring and most seems to check out, however, continuity testing the PCB mounted transformer yields nothing (neither primary nor secondary winding), perhaps it isn't supposed to and I am confused but I think this tells me the transformer is FUBAR. So in a similar situation to the linked thread, i need a new transformer, however, mine does not have a nice clear part number on it to search for so I think i have located the correct part but would appreciate some confirmation from those in the know.

Here is the current transformer


this is the part i believe is a suitable replacement http://au.rs-online.com/web/p/pcb-transformers/7320342/

I will (when I get a minute) post up photos of the restoration process

Thanks, much appreciated

It's unusual that both windings would fail at the same time. If the pins are in the right locations and it's the same height or at least not to tall, that looks like a suitable replacement. I've also seen the diode bridge after the transformer fail so you might check that also before ordering parts.

Ira

I was looking at the measurements and figured it would be a good idea to run some callipers over the current one to make sure the new one will fit.

Does a circuit diagram for the PCB exist anywhere? I wouldn't mind checking it out.

This is the wiring diagram that matches my Giotto, which also shows the part number for the proelind control box.


Thanks

ira wrote:It's unusual that both windings would fail at the same time. If the pins are in the right locations and it's the same height or at least not to tall, that looks like a suitable replacement. I've also seen the diode bridge after the transformer fail so you might check that also before ordering parts.

Ira

It appears I was mistaken, the secondary winding does indeed have continuity. So it is only the primary that is cactus.

The Bridge rectifier has continuity.

It appears the new transformer is 0.8mm taller than the original, but I doubt that'll make too much difference.

So I need some help.

I got the new transformer and it doesn't have continuity on the primary winding either. I assume this is an error I have made. Both the new and old transformers show no continuity on primary winding, but both show a high resistance of multiple kΩ.

So assuming this is correct and the original transformer is working.

What is the likely failure issue I have and what should I test and how to try and determine it? How do i test the relay?

Thanks

Vovo, from what I can gather from OP, you mostly dove straight into the control box, whereas there are a number of basic components that could be checked first. Namely, does the element have continuity? Does the attached thermostat have continuity? I understand pstats, when they die, moslty die leaving a closed circuit, but this may be the opposite for you? Can you confirm the pstat still functions normally? I gather you could always bypass it for a few seconds to check if you can heat up the element (making sure the boiler is full).