QM67 Owner Feelings (New Model with Dual Gauge)

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checkers3333
Posts: 6
Joined: 3 years ago

#1: Post by checkers3333 »

I bought this machine a little over a year ago and would like to know if anyone else has had the same experience. The machine is pretty temperamental. On its good days, it's a great machine. On its bad days I have extremely inconsistent temps in both boilers.

At best, my brew boiler is within 1 degree of the target and that seems to only be if it's set to 200F (ranges 199F-201F)
If I set my brew boiler to 201F it ranges from 198F to 204F which leads to very inconsistent shots back to back with everything else the same

The steam boiler is another issue. Something in the temperature sensors or PID isn't right. My PID will show 244F when it's set to 255F so the heating element is still on (indicated by the yellow light) but my OPV is opening up and my pressure gauge is buried past 2.5 bar. Then for a couple seconds it shows what is the true boiler temp of 293F! (before going back to 244F or something else under the set temp)

I really feel like I should have gone with another machine. At $2300 I didn't exactly cheap out on this machine :(

JRising
Team HB
Posts: 3718
Joined: 5 years ago

#2: Post by JRising »

It's strange that your brew boiler is inconsistent, but that's insignificant when compared to the steam boiler issue you have to fix.

It certainly sounds like the PID controller is accurately reporting the bad signals it's receiving from the thermo-sensor, so my bet is a bad NTC sensor, but maybe it's just a bad connection at the electrical connections between the sensor and the box. Check.

User avatar
GC7
Posts: 1112
Joined: 16 years ago

#3: Post by GC7 »

I have been very happy with the performance and temperature stability of my QM67.

After 2 1/2 years I did have an issue with the steam boiler water refill as a result of the pump losing priming. That led to a frustrating set of issues that required a trip to Chris Coffee who diagnosed the problem and fixed it with a new pump and temperature sensor. As mentioned by the very helpful suggestions of JRising, you likely have a minor problem.

I don't see any significant differences between any of the new vibe pump dual boiler machines in reliability or temperature control. Same with the next step up in rotary pump models.

Good luck with your fix.