Dave you are increadibly helpful - thank you.
With your guidance I have confirmed the pump does still work. That’s a relief in terms of repair cost.
With the heating element for the service boiler unplugged I am able to get the brew boiler to temp and it does shut off. Which is great!
The inidciators on the front show that the right side light remains illuminated - is this the service boiler? Also you are correct that I couldn’t register continuity on the relay (that surprised me).
I’m short on time today, so I didn’t have a chance to switch SSRs as you recommended, but based on the above I’m inclined to order a new SSR for the service boiler.
To answer your question, yes my circuit is 20Amps - future proofing for whatever machine is next (hoping that’s not for a while with today’s economy)
Your suggestion of an in line fuse is sensible. There’s about 6-7 other fuses in the machine. Somewhat odd that there isn’t one for the mains. I might add a breaker right before the mains switch.
Lastly, since I’ve got this whole machine opened up. Is there a suggested descaling (edited for spelling) procedure?