Caleffi thermo-electric valves breaking

Jack_Arnott

Hello all. We had a new house built in 2014. It has radiant floors for both heating and cooling. The valves for the zones are Caleffi thermo-electric, which open when a low voltage source is applied to them, and wax is melted. The installer was super stoked on these, as they are supposed to last millions of cycles, with no moving valve parts. Almost immediately some of them broke, right near the top where they thread in, they would pop off slightly on one side, and hang crooked. The valve then opens when any other valve is open. The installer blamed it on other contractors banging it, as they had never seen one single failure, and replaced them. Then it kept happening. One time one was broken for 8 months before they replaced it, and the next day another one broke. The contractor yelled at me and said that I was sabotaging my own system, and that at some point it would have to be my problem. Someone else in the company finally convinced Caleffi that they had a problem, and they gave us a new manifold, which the contractor charged us to install, and also replaced the valve that was broken. Not one month later, and a valve has already broken, and another looks slightly crooked.

It seems to me that only one valve “needs” to be broken. I have searched for this problem, and found nothing.
Any ideas on what could be causing this? (Sorry for the length, but want to be a thorough as possible to start with.)

JUGHNE

What is the source of the chilled water for the floor cooling?
Do the same valves control the heated water and the chilled water?
Pictures would be great.
We seldom see radiant heating/cooling in the floor.
Thanks.

Jack_Arnott

Yes, it is the same system for heating and cooling. The same valves control both.
Here is a broken valve on top, then some more pictures:

Jamie Hall

For some reason -- apparently specific to your system, as those things are super reliable -- the valve itself is being prevented from moving. When the actuator operates, then, it puts tremendous stress on the assembly and, no surprise, it breaks.

All that is easy to say. What's not going to be so simple is figuring out what, specific to your system, is preventing the valves themselves from moving.

Jack_Arnott

Thanks for the comments so far. The valves are moving fine. Even after breaking. It is the nylon collar that is breaking. Is there supposed to be pressure on the valves when they are not open? Because the pump is going as soon as it calls for action, and the broken valves all show water movement in them. Then, slowly, the valve opens, and the green ring shows. Is something backwards, EG, the water flow going to the back side of the valve instead of the front side?

hot_rod

Ruling out any force or objects falling or leaning against them, of course.

If the pins in the valve are sticky, usually from bad water quality this can stress and break the actuator body.

Excessive cold temperature 32F or below can make the case brittle, I doubt you are running that cold?

Are they sweating and getting wet with chilled water running thru the manifold?

Yes we have had other failures and we send them back to the lab for forensic analysis. In one case harsh chemicals stored in the room attacked the housings, others failed due to stuck or sticky valve mechanism.

If you have failures on brand new manifolds, with clean water, and the valve pins moving freely, we would like to get some of the failed ones back to analyze them.

Attn: Cody Mack
3883W Milwaukee Rd
Milwaukee, WI
53208

I'll forward this thread directly to Italy for a response.

I'll be glad to help determine the failure cause and remedy the problem.

Here or at bob.rohr@caleffi.com

Jack_Arnott

Hi Bob, thanks for the response. Right now the temperature in the buffer tank is about 50 degrees, exiting the heat pump at 45 degrees. The system works harder when there is a larger temperature differential, hotter days, but I don’t remember anything lower than 40s, but don’t watch it much anymore. There might be slight sweating, but I don’t remember seeing anything, and it is slightly filmy to the touch. We are in SLC, fairly low humidity. To be clear, we are cooling right now, not much, it didn’t turn on till mid afternoon today, and only one zone right now, but when the first failure happened, it was winter, and we were in heating mode. And it was a brand new system. We noticed the first failure after a couple of months. One failure happened the day after the last one had been fixed, summertime, cooling mode, which leads me to think there is some kind of pressure thing happening in the system, that was not happening when a valve was broken. Also, of the 8 zones, most of them have broken, maybe the same ones several times, but not one specific one that I know of. It seems like it must be system specific, not batch specific, to happen over many years, and we did just get a new manifold. Our water is not great, but not very bad either. Shower heads will need cleaning after a couple of years.
I don’t know what happened to the old valves, but we can send one or all three bad ones to you. Should I just take them off and send it to the address? Will I need another one on there? It does not seem like it to me.

hot_rod

I've sent a link of this thread to Milwaukee, Kevin and Cody will keep on it, as I'll be out tomorrow and next week. Maybe they can send replacements to get the bad ones back.

If you remove an actuator, the the valve goes full open.

Missing the Wasatch, I lived in SLC, at Snowbird and Park City for 24 years.

Jack_Arnott

This response indicates that I have not described my problem accurately. When I say that the valve breaks in my title, I can see how it would lead to confusion. To be clear, it is the casing on the actuator that is breaking. The valve portion itself continues to work just fine. In the picture attached, you can see that there is flow in the first zone, even though the green extension is not out on the valve. The casing is not holding the actuator (which I thought was the valve) in place properly, so the unit is full open, even though the actuator itself is still closed. Zone three is open, (green protrusion) but it was allowing full flow before it opened, because the casing is broken.

This leads me to the question, should my circulation pump be going, before the valve opens? Is the fact that my pump is on, and putting pressure on the valves before there is anywhere for the flow to go causing my problem? I happened to be in the room when the pump kicked on, and immediately there was flow in the three zones that have broken casing. But if the casing were not broken, would this be causing them to break?
After a few minutes the valve did open, so the call for water flow, and valve to open is happening at the same time, but the flow will not usually happen for a few minutes, until the wax melts, and the valve opens

Back to the quote, removing the actuator and the valve going full open will not be a further problem, as that it the state it is in now.

hot_rod

I think you have it right and we are on the same page.

If the plastic "heat motor" actuator is removed from the brass connection or broken and not attached to the brass body, that valve only will be open.

Looks like you have a Grundfos Alpha pump. If it is set to the delta P function, or Auto Adapt it will slow down or speed up as valves open and close. With all valves closed the pump should idle at @ a 7W display.

OR the pump could be wired to only run when any actuator is open. Depends on how the installer configured the system.

Either way the pump could not damage the actuator, even if it did run full speed with all the actuators closed. Although the pump would be dead headed and not be happy in that condition.

It takes about 3 minutes for actuator to heat up and open, about 45 sec to close.

JUGHNE

Should there be a time delay before the pump starts?
I have several pump and dump heat pumps, I am thinking of the Taco water valve that is slow opening and has a set of end contacts that will then start the Water/air heat pump.

PS. 3 minutes is quite some time for the pump to dead head with no flow????