4 Way Mixing Valve Education!

Cyclist77

I currently have a Tekmar 3 Way Mixing valve on my radiant heating system using a coal stoker boiler. Looking to understand 4 Way Mixing Valves. Is this screen shot a good representation?

hot_rod

The main difference with a 4 port is you get two mixing points inside the valve. So it can both mix down a temperature for a low temperature, and mix up the return to the boiler to protect it from low return temperature.

They were very common with copper tube and cast iron boilers connected to low temperature radiant.

But to be effective they need an actuator with sensors that react to two temperatures.

ODR was another function built into many of the controls that run the actuators.

Many of the mod con boilers have functions onboard now also to send a signal to a mix valve actuator.

Here is a look inside to understand the difference between 3 and 4 port mix valves.

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Cyclist77

Bob,

So with a 4 way it would have a way to sense outdoor temp as 1 of the temps?

Cyclist77

Can a 4 way just be operated manually a d not have an Actuator?

hot_rod

yes to both questions the ODR is usually in the actuator. Some valves, like Taco have the control built into the actuator

Without an operator it is considered a “dumb” valve It can only respond to manual input

Cyclist77

Dumb valve -perfect for me!😀