Brew pressure, boiler insulate, preheat HX coil for Isomac - Page 3

Need help with equipment usage or want to share your latest discovery?
User avatar

#21: Post by Kristi »

wow - that line IS flat, even with your short (to me) line next to the boiler. Nice!!! Yes, I will insulate the line to the HX, as well as the whole group istelf. This should also increase warm up time, and lower the necessary pressurestat reading.

I will insulate the hotwater line, not because I use it, which I don't, but to further protect the boiler.

Definitely I'll have to spend a bit of time with her before I mod her - determine condition and deadband of pressurestat, and heater, and OPV, and solenoids, etc, as well as obvious decal'ing and looking inside boiler and possibly HX.

User avatar
cannonfodder (original poster)
Team HB

#22: Post by cannonfodder (original poster) »

While the HX preheat line is relatively short, you only need two ounces of liquid. There is more tubing there than you may think. It has been a while but I believe I have around 1.5 feet of ¼ copper around that little boiler. The low volume and slow flow rate of the water gives it plenty of time to heat while in transit to the HX input. I have never measured the temperature at the input side of the HX (after the preheat), but it does a decent job.

I did have a couple of problems. The largest of which were the metric fittings with US pipe. In the end I soldered the feed line going to the T and the return line to the HX to the OEM fittings. If you look close in the photo you can see the weld joint between the fitting and the pipe. These were just the short pieces, everything from the T to the right angle fitting back down to the HX input is compression fitting attached. At the time, I had no BSP to NPT adapters. If it ever comes loose, I will replace the soldered fittings with the proper adapter.

The other was bending the tubing. I never took the boiler out of the machine. So I bent the tube one small section at a time and snaked it through the machine as I went. In retrospect, I would pull the boiler, bend the tube and put it back together if I did it again. Over a year later and it is still pumping out the liquid love.

I also run a lower Pstat setting, 1.0-1.1.

Excuse the mess; I just cranked out 5 double cafe mocha's. This is my office setup so I have to share.
Dave Stephens