Normally Closed Thermal Actuator for Bluefin Manifolds

Work great

Like others here, I thought multiple units I received were defective. After a series of readings, I found a few items from the MFG manual "The actuator mechanism of the OEM-Actuator uses a PTC resistor heated elastic element and a compression spring. The wax element is heated by applying the operating voltage and moves the integrated piston. The force generated by the movement is transferred on the piston lifter and thus opens and closes the valve." -The "dead time" can be up to 3 min between the application of power and the actual opening of the valve, similar to the closing time, remove voltage and it takes quite a bit of time. "In its delivery condition, the OEM-Actuator is kept open when de-energised due to the First-Open function (filling). This enables heating operation during the carcass construction phase even when the electric wiring is not yet complete. During the later electrical start-up, the First-Open function is unlocked by applying the operating voltage for more than 6 minutes. The OEM-Actuator will then be completely operable."

Easily installed on my Bluefin manifold. The only reason I didn't give it a 5 was that it was unclear to me about the wiring for these. Since these are only 2 wire actuators, I had a 50-50 shot at it. I guessed wrong and just needed to reverse the wires to enable the actuator. These interface nicely with the Sage Zone panel.

I installed 10 of these actuators, replacing another brand that only lasted 1 year. I have already replaced 2 of the 10 in just over a year of service. I have not found a brand that is reliable yet.

Have replaced 5 out of 20 valve actuators on one job. They get warm but don't retract.

I bought one of these to test on my Mr. Pex 10 loop manifold. I chose this one because it was a two wire which is what I need. It is connecting to a Tekmar 335 zone control so I don't need the end switch. Well It screwed on perfectly, I applied 24 volts and nothing happened. No movement, no noise, nothing. So I assumed it didn't work and returned it. Tech support wasn't much help but customer service was good, the return was easy. Now I don't know what to do, I need 10 of them but am skeptical.

Had I known about this earlier, I would have bought the part MP700 which is compatible with Rifeng manifolds, has 4 wires instead of 2, and is sensibly the same price.