Weil McLain, second wall mounted combi unit leaking.

BenryPA

In 2020 I purchased my current home that had a Weil McLain AquaBalance AB155 which had been installed in 2017. The boiler was leaking at the dhw heat exchanger. There where receipts from installer for attempting to correct the leak. The installer again attempted to stop the leak with no success. Weil McLain agreed to provide a replacement unit. Installer agreed to charge me 50% of installation cost. Fast forward 4 1/2 years and the replacement is leaking at both the primary heat exchanger and secondary heat exchanger. Is the brand just junk or is this common for most condensing combi units? Is there a reliable alternative or go with CI boiler and indirect dhw,

Ironman

There are several good mod/cons: Lochinvar, HTP EFTU are the ones we primarily sell and install. I’d recommend those in a heating boiler + an indirect.

Let me also add that the installer is more important than the brand; he’s 95% of the equation.

You probably have other issues in your system that are causing the premature failures of the heat exchangers. A good tech will find and correct those issues before simply swapping out the boiler.

GGross

Not my preferred brand but a heat exchanger failures generally are more site conditions/install related, than manufacturer defect. it's hard to tell without being there. For example if the system takes on a bunch of untreated make-up water that will greatly increase every brands risk of failure.