Rocket Giotto HX machine burned wires!

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
damadama

#1: Post by damadama »

Hi,

I was hoping someone could help me diagnose this issue and whether or not it is in my capability of repair.

Yesterday I noticed my boiler pressure was quite low and group temperature was as well. Tore down the machine last night and noticed the contact points for one of the hi limits were completely melted. The other ends of the wires going to the control box and pressure stat seem fine, as do the connections on the other hi limit.

The damage looks similar to what I see in this video: http://www.youtube.com/watch?v=TPDoWD5wlo8 ... see photo https://imgur.com/vgM90ck.


Does it seem reasonable to try and replace these parts, or could there be a larger problem here that I'm not aware of?

FWIW I just ordered a Linea Micra, so just hoping to get this thing running to give to a friend with my old baratza vario grinder. Just don't want to toss in the landfill.

ira
Team HB

#2: Post by ira »

Replace both connectors and the thermal switch and you should be OK. Looks like one of the connectors had a bad crimp or got wet and corroded. Either way, it's a really simple fix unless the one wire is to short after cutting off the damaged section and even then it's only a bit harder.

JRising
Team HB

#3: Post by JRising »

That hi-limit was going bad, making bad contact and generating its own heat. Simply replace the high-limit and both of those wires and the machine should be back in shape.
If there's plenty of wire left so that you can cut off 3 or 4 cm, crimp a new connector and re-use the same wire, then that will work, but be sure to cut off all of the wire upon which the insulation has gone hard and brittle. If the wire has been that hot under the insulation, don't trust it anymore, use only nice flexible wire that feels right.

If you're replacing the wire, go with a high-temp 14 AWG rather than the 16 AWG that Rocket uses. The slightly heavier wire will conduct more heat away from hot spots and things will just last longer. Better wire is a very inexpensive upgrade.