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Caleffi AngleMix 520 (and Lochinvar Noble Combi questions)

Currently have an AngleMix 520 3/4" on a power vent gas tank. Planning to switch to a Noble Combi for mixed space heating use.

I noticed that the instructions for this combi require an ASSE 1070 mixing valve on the DHW output, though a Caleffi AngleMix 520 3/4" valve is currently installed on a regular tank, which I understand has similar functionality as most 1017 valves (it was mentioned that dual listing was a work in progress in the forum previously.) Apart from not following the instructions exactly caveat emptor, should I expect any seriously detrimental behavior? This is an ideal valve otherwise I understand due to the 100% shut on hot in a recirculation application.

It's currently set to "7" (just below MAX) to output ~120-122 F water at the mixing valve gauge (giving about 115 F at the fixtures) with an input of about 140 F from a regular power vent gas tank set to "B". Given the recirculation, I'm hoping to avoid lower temperatures.

Also I think I installed the checks without the included o-rings as they were separate in the box. It looks like there isn't a non-destructive way to remove the checks and since this is a recirculation application, I probably should try to replace them and install the o-rings? I have the screens in but on city water with a 20 mesh Y-strainer at the PRV after the meter these are probably not needed? Any idea what the part number is for these checks?

Thanks for any advice!


  • Mustangman
    Mustangman Member Posts: 113
    Just today I got called to look at a boiler that was leaking. Once I made it down the steps there was an old Axman Anderson NPO that was left in the basement for decoration. After tripping over the oil line that runs across the floor, I damn near fell into the Combi boiler. First thing I noticed was no mixing valve. Come to find out, the homeowner installed the boiler. I asked him about his water temperature... he said it seems hot at times and at times it fluxuates. Went over what the mixing valve does and he was for it. When we go to fix leaks, we are putting in a mixing valve. I like the Taco 5000. Sorry Hot Rod. Calefetti is not big in this area.
  • chrismarcellino
    chrismarcellino Member Posts: 7
    Thanks. I may have answered one of my own questions. It looks like the 520519AC that I have, with its checks in place, is dual listed as ASSE 1017 and 1070 per https://www.caleffi.com/sites/default/files/media/external-file/03643_NA_0.pdf so I think I'm good.

    I ordered some of the check valves so I can get the O-rings in correctly, and I think I'll forgo the strainers. Thanks!
  • hot_rod
    hot_rod Member Posts: 22,260
    The main difference is a 1070 is limited to 120F
    A. Dual listed valve will have a stop built into it to lock it at 120
    Also a 1070 must have checks, they are optional on 1017
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream