This whole ordeal started when i was replacing my solenoid valve and all the screws broke off in the base. This led me to replacing the entire group head collar service kit from ereplacement parts.,

This kit includes the following: shower head screw, thermal fuse, group/shower head, 58mm portafilter, two-piece collar insert, thermostat, collar, and four screws.

After install I cannot get my machine does heat over 160f. I am guessing it has to do with the thermostat or the thermal fuse but I could really use some help. Thank you in advance

This is a late reply, but if you're still stuck, it may help.

I purchased a malfunctioning dual boiler that was having a very similar issue - wouldn't heat all the way.

The water to the group head is pre-heated by the steam boiler, and I discovered that the steam boiler wasn't heating up at all.

My understanding/assessment based on quite a bit of time tinkering with this machine (it's been working fine for several months) is that one of the reasons the steam boiler wouldn't heat is if it doesn't *sense* that it has water in it.

I've found two reasons at separate times why my steam boiler wouldn't sense it was filled with water, even when it was:
1) Excessive scale buildup on the probes inside the boiler.
2) The fluid in the steam boiler is too much descaler, and not enough water. (I assume this is an electrical conductivity issue)

If it's not already fixed, I hope that helps, and if it is fixed I'm interested to hear the solution!