Here is a recap of our phone conversation:
It was a pleasure talking on the phone with you. I was really exciting for me as well, as you are in the espresso business and you have an employee running a event with a portable set up and having a problem with a machine, and i can relate as i too also have a espresso company my wife runs, and I help customers on fixya. So I know exactly what your talking about, and i know the pressure you are under when a machine goes down, while you are trying to serve customers, especially when you have to help your employee over the phone.
The problem with the machine, is that you are not getting water to it and of course the red fill light is not on. Sense you just move the machine , portable set up down the road for example, that you said it was working fine, but when you just moved it to a new place that your employee wanted to sell some java, the machine does not now,fill with water or lets say pump water from the main water source.
Once we talked, it all main sense , and i feel i knew exactly what the problem is, You said this was a portable set up, meaning not hard water tapped. Meaning , your using like a five gallon fresh water supply, that you have a portable shur flow pump, that the pump sucks the fresh water out of bucket of water, and of course other ends goes into water inlet of machine. Nothing wrong with that, this is standard normally use and procedure for portable units, stands, portable building drive thru's etc.
You are suppose to have a inline filter,but you said, and i have done this too, sense it was just a little small event, you did not hook up the inline water filter. Yes, its possible, jets might have got clogged in machine, because of no inline filter, but i doubt it in this case.
Here is where i believe your problem is, and this happens all the time, to me on my locations and to all portable shur flow pumps. They get vapor locks real easy, especially when moved, as you just did. The pumps have a diaphragm inside and what happens especially when there turned off at the 110 plug and then moved, and replugged in and the hose back into the bucket,a couple things happen.
Number one. The hose line gets air in it and has to be primed ( vapor lock) primed is getting pump to start pumping, the shur flow pumps are great, but you kind of have to help them almost like siphoning gas. They are low voltage and 110 power, and not real strong for water pressure. What happens, when you unplug them and take hose end out of water, and move set up, and then try and hook it up, sometimes the diaphragm inside of the pump, gets stuck, and have to help get it flowing or should i say pumping. You can do this, by putting hose side in fresh water side, then other end of pump ( the line that goes to machine) take that hose off, then plug in pump, and un-plug. Use a small piece of wood, or lightly tap pump area on casing and then plug back in. Sometimes this will free up the diaphragm that will get stuck, if vapor lock. Do this a few times until you can get the pump sucking the fresh water out of the bucket and it starts squirting out the other end( that goes to machine),
Now this all being said, you stated on the phone, that the shur flow pump you have, is about 6 years old, from my own experience, they only last at full capacity for around 2years, maybe 3. I know I use them too, and have had my espresso company for 17 years. I always have a back up. Even tho your pump might be working, the diaphragm is getting worn, and I hate to say it, this problem will happen again, as it is getting worn. It probably is time at least to have a back up, just in case, you cant get it going. Eventually the diaphragm will get stuck and stay stuck, or what will happen, when you have it hooked up to machine, you will here the pump, pump every now and then, on its own for now reason, meaning, its leaking past the diaphragm, Here is also a web site that if you scroll at the bottom right, it has your machine to download your machine and the trouble shooting guide, The link to copy and put in your browser is https://www.coffeehomedirect.com/grindmaster/1750 that will show you everything, but it does not talk about the shur flow, as from my experience and yours that this is most likely where the problem lies.
Ok, been a pleasure and I hope this information helps you, i recapped this more than i had to, but i wanted to make sure we both understand what the problem is, and others who read this post, maybe it can help them. Thanks Again, Mike (Mr. Bean Man)