I owe the forum an update on my lack of steam boiler heating reported several weeks ago.
The symptom and Investigation: The heating stream graphic was on but the white LED did not illuminate. Paolo initially suspected the limit switch on the top of the boiler but later I checked with a multi-meter and verified this was operating correctly. Paolo also asked to check the voltage across the heater which required access on the underside via the small panel and great care as the machine was live. Anyway this showed no voltage - in other words the problem was was not caused by defective heaters. I traced the wiring to the lower of two solid state relays in the RHS electronics panel. These are black components about the size of a pack of cards.
Cause: It turned out that the output wiring connections were very loose - in fact it looked like the solder used to join two wires was uneven or had deformed perhaps due to heat. These were re-soldered and a ferrule used to ensure good connection.
If you have similar heating problems or have the side panel removed for some other reason it would be well worth checking that the solid state relay terminal connections are all tight. Be sure to isolate the machine from mains first.
