Dealing with a boiler that won't fire up or control heating zones properly? The Honeywell L7224U aquastat relay is a common replacement part for older hydronic heating systems. This model (also listed as L7224U1002 or L7224U-1) is used to control circulator pumps based on boiler water temperature. It's a straightforward swap if your existing relay has failed—just make sure to match the model number exactly. Typically installed on the boiler itself, it helps manage when the pump runs to send hot water to baseboards or radiators. If you're not comfortable with wiring, it's best to have an HVAC tech handle the install. A reliable OEM-style part to get your heating system back on track.
