Hello to all,
I have in my possession an Isomac Relax that I'm working to fix for somebody. Was told it had worked, but little to no maintenance was done to it. Then it was put into storage for 2 years I think and then they couldn't get it to pump. The machine except for being really dirty internally (group) is in great shape. I was able to finally get the pump primed. Took quite awhile, but it did eventually take off to pumping. Knowing it has a vibe pump I was careful to not run it too long to avoid overheating. The boiler did seem to heat up some, but something seems to be amiss. When I first turn the machine ON the pump automatically runs for quite a bit, maybe 30-45 seconds. The green light never comes ON, which I'm assuming is an indicator of the heating element being ON. But since I've been checking into it the green light has never came on, even though it did appear to be heating at one point. I did get some steam out of it as well as some hot water from the tap. A few things to point out... the boiler was not empty when I started the machine up to get the pump primed so I don't think the element ever ran dry. Also there is plenty of water in the tank which has a low volume shut off. I'm thinking possibly the thermofuse might be an issue. Also, why would the auto fill feature run that long on start up? Maybe a sensor fouled, I dunno. I haven't been able to find alot of info on this machine so I'd appreciate any info or tips. Thanks in advance.

The pump runs to fill the boiler. Most Isomacs have a green light (boiler hot enough, heat off) and a red light (the opposite). You are looking for a dial that goes up to 3 bar -- the machine will be warm when it hits around 1 bar. You will also need a blind or backflush basket to check the pump pressure, on the dial that goes up to 15 bar. It should be at 11 bar.

It sounds like you took on this repair project without knowing much about HX espresso machines.

Thanks for the reply. I do know a fair amount about HX machines, but more on a commercial level and not one with a vibe pump. Yes I do know it has an auto-fill feature, just thought it was running a bit too long. And I also know exactly what both gauges are for. Would be nice to have a manual to know all the ins and outs of this machine, that's all.

Sorry to sound condescending in that case.

The auto fill is connected to a Giemme black box, and it sounds like it works -- vibe pumps don't have nearly the peak flow rate of a rotary and boiler fill takes about a minute.

The pstat doesn't drive the heat directly, there's an SSR. It's not properly heat sinked on the stock models, and may burn out (in which case no heat); when you replace it, use heat sink compound and polish the case where it attaches. The SSR is always connected to the hot, even if you turn off the machine, so disconnect the power before you work on it. (the electrical wiring is flimsy 18 gauge, 220 volt/6 amp stuff, not good for 110 volt/12 amp service, but somewhat usable -- expect to see heat marks on all the connectors)

The pump has an OPV that can be used to adjust the pressure -- there's two, a small non-adjustable one as a protection, and a large one with a screw adjustment. Set it just like a rotary, except there's a lot more pressure drop from blind filter to flow, so set it at 10 to 11 bar. The OPVs can be found by tracing back the second hose in the water tank

That's about it

Thanks for that info Jim. Was reading a bit of the actual owner's manual (found online) and it gives in detail the lengthy process they (Isomac) recommend for each start up period as well as after steaming. Sounds a bit specific and like a PITA to me, but if it is what works then so be it. They say to allow up to 3-4 minutes for the system to pressurize after the auto fill does its thing. I think everything on the machine is working OK, just really needed a bit more specific info on the functions of this particular machine. The pump not priming was the real issue issue, but I took my time and carefully got it to pumping again. Owner said they use softened water, but something was seized during storage in some way or another. Will do a water debit test to make sure it is OK as well. Seems to be based on the rate water is being pulled from the tank. Biggest thing after that was/is backflushing and cleaning up that nasty group. Did a few detergent backflushes, then have been using just water and it's still comes out slightly dirty after 10-15 cycles. It is almost normal once again, but I simply can't believe this sort of PM was never done in the first place. The owner said her husband is to blame for that. I just want to get it 100% again for them so they can either enjoy it or sell it (her words not mine). Anyway, thanks again Jim for all the info as it surely helps. Have a good one!