Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Monitor MZ 25C Freeze Protection

crichardscrichards Posts: 2Member
i've grown tired of the long, dark, cold winters up here in eastern Washington and want to become a snowbird in Arizona. I need to add freeze protection to my hydronic heating system so I can leave in the winters. I have a monitor MZ 25C boiler that is piped directly in the system. The owners manual describes a product called BIONIBGEL for freeze protection but I've been unable to find any suppliers for this product which aparently comes out of France.

The pex I installed in the floors is non-barrier. That's a mistake but one that can't be corrected. I am thinking I'd like to install a buffer tank to help with short cycling, and to isolate the boiler from the rest of the piping and use oxygen barrier pex for that part of the system. I will just run traditional glycol in the floor piping but I'm not sure what to run in the boiler/buffer tank. The heat exchanger in the boiler is stainless steel but the water jacket is aluminum. Can I just run an antifreez that is compatible with aluminum boilers? What's so special about BIONIBAL/ BIONIBGEL? Is there any place I can buy that stuff in the US? Is there something equivalent I can use? I don't want to destroy my boiler with bad circulating fluid and I don't want to purge the system every time I leave for the winter.

Aluminum safe glycol is not cheap, by the time I install a 50Gal buffer tank I'm looking at some serious money for the freeze protection. Thanks for any suggestions.


  • hot_rodhot_rod Posts: 12,042Member
    It might be time to consider a boiler upgrade? With non-barrier pex you can either separate the system with a HX or use all non ferrous components.

    A new mod con boiler, properly sized, could eliminate the short cycling, and the need for AL glycol. Combined with piece of mind knowing you have new equipment with repair parts availability.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • I buy the MZ BION... from:
    Robert Kushner (Robbie)
    Budny Fuel Oil Company
    Robbie is a good guy to work with and the price seems fair. He ships quickly too.
    The concentrated water treatment goes a long way. I'm not sure if it is an antifreeze as well or not.
  • crichardscrichards Posts: 2Member
    Thanks for the tip!
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!