Uponor actuator noise?

Paul S_3

I replaced a few actuators for a customer of mine.....now when the actuators open we get a "water hammer" type noise....like a constant knocking.....i do not know if this was an on going problem because he just purchased the home....any ideas? I replaced the 2 outer actuators a few weeks ago .... i returned to install another radiant zone for an extension to the home.....im using the Uponor trueflow manifolds with the same actuators....

Dave H_2

Paul,

Whenever new thermal actuators are installed, you want to cycle them at least once for a few minutes. They are manufactured slightly open. They are made that was so that it is easier to install on the manifold.
That however doesn't answer your question, Seeing that you have brand new actuators in the middle and an older manifold, are the adapter rings used the originals that were there or new ones that came with the actuator?
The different adapter rings are needed for different manifolds and the associated valve bodies in each. They all have a different travel distance.
I am not sure which way to go but my guess would be to re-use the rings but I am not too familiar with the new actuators.
Also, those are not the truFlow manifolds, truFlow was an extruded brass, those are the modular cast brass manifolds

Dave H.

Paul S_3

Thanks @Dave H

Mark Eatherton

Sounds like the water is flowing through them backwards. They are made to close off AGAINST flow. When you run water through them backwards, if numerous zones are calling, and one of the zones closes, as the plunger gets close to the seat, it sucks it into the seat and causes a WHAM.

In some cases I've heard, it continues to hammer, but tapers off until fully seated. Check main circulator. Easy to inadvertently install it backwards.

If the return manifold is hotter than the supply manifold, then it confirms my suspicions.

ME

Paul S_3

@Mark Eatherton i think your are correct all of the manifolds in the home are installed on the supply with the actuators...the paper work states that these are return manifolds....this is one i replaced the other day..previous one was leaking....this is the supply manifold...theres about 20 of these in the home all installed on the supply ....

Mark Eatherton

Easy enough to figure out, but may not be as simple as flipping the pump around, depending upon the heat source, and hot it is configured. Might be easier to flip flop the manifolds instead of the pump. As with any hydronic question, the only correct answer is "It depends..."

Good luck with your project. Wonder why they switched tube type.... Red isn't normally a heating color for Uponor tubing. Hope you're not also looking at non barrier tubing on a ferrous system.

ME

Paul S_3

Thanks @Mark Eatherton ....its barrier tubing ....i replaced this manifold because it was leaking....red tubing was installed a few years back by some knucklehead plumber...there has to be a coupling embedded in the slab.....on the return manifold its all grey uponor tubing

Mark Eatherton

Sorry Paul, I should have been clearer. If the red tube is non barrier, and the system has ferrous components, your system will degrade unless you maintain a good pH around 7.6 to 8.5 on an annual basis. If there is aluminum in the system, that number is different. You'd be amazed at how much oxygen can enter through that short piece of tubing. Red and Blue Uponor tubing are non barrier potable water tubing, if in fact it is Uponor tubing.. The Uponor tubing is normally white. If it is showing grey, its an possible indication of oxidation occurring within the system.

You're welcome, and glad I could help.

ME