The TECOFI BM3102 is a French-made manual 4-way mixing valve designed for hydronic heating circuits where supply and return water temperatures need to be blended before distribution. Its cast iron body and bronze seat seal provide durable service in closed-loop systems at up to 110°C. Female BSP threaded connections from DN20 to DN50 allow direct inline installation on standard pipe threads without flanges or adapters.

How does a 4-way mixing valve work in a hydronic heating system?

In a heating circuit, the BM3102 has four ports: hot water supply inlet, cooler return water inlet, mixed-temperature outlet to the heating circuit, and return to the boiler. By rotating the manual handle, the operator adjusts the proportion of hot supply water blended with cooler return water, setting the desired flow temperature for radiators or underfloor heating loops. Unlike a 3-way valve that only diverts or mixes at one point, a 4-way valve simultaneously balances both the heating circuit supply temperature and the boiler return temperature — preventing thermal shock to the boiler and ensuring stable system operation.

Manual vs. motorized mixing — when simplicity wins

The BM3102 is manually operated, suiting heating circuits where the mixing ratio is set seasonally or remains fixed after initial commissioning. Without an actuator, there is no electrical wiring, no control signal, and no risk of motor failure. For variable-temperature systems requiring continuous automatic adjustment, TECOFI offers motorized 3-way and 4-way variants. The BM3102 fills the niche where hands-on reliability is more valuable than automation.