Navien 30004831C Motorized 3-Way Valve

If your Navian combo boiler doesn't make hot water or heat this is the most likely reason. Difficult part to replace because you have to takeout the pump to get to it and screws tough to remove. Fortunately they give you the replacement brass threaded pipe connection if you can't get out the original screws and have to cut it out which I unfortunately had to do. Boiler is back working great and I saved some serious cash.

Factory navien part. Saved me from a really chilly shower. Thank you.

Perfect fit

Works perfectly easy to install saved 2 thousand doing it my self

Saved me a ton of money! Works perfectly, exact fit, I have nothing negative to say about it.

This is the valve that is important in a combi boiler when using the Navien for heating and Domestic Hot water. This is the motor that diverts hot water when it is being called for Domestic Hot water or when heat is being called for. This is the exact replacement for the NCB-240 Navien Model which is what I used it for.