EcoTech EZ VS Motor - Don't Count On Built-in Freeze Guard

[Chuck_Davis]

After extensive testing, replacing the controller/freeze guard and communicating with U.S. Motors, the recommendation from U.S. Motors is to not count on the freeze guard that is built into the EcoTech EZ VS motor to protect your pool system.

The built-in freeze guard is supposed to cycle the pump on and off 30 minutes at a time, running at 30% flow, whenever the temperature drops below 40 degrees.

I don't close my pool in winter, and I'm located in Central North Carolina, so I need freeze protection.

After noticing that the freeze guard on my motor appeared to not be working, I contacted U.S. Motors. The customer service from U.S. Motors was excellent, and they sent me a replacement controller board to try, but the person I spoke with also acknowledged the possibility of a design defect. The replacement controller showed the same symptoms. In a follow-up e-mail after I reported my test results it was acknowledged that the built-in freeze guard is unlikely to function properly and that they are working on a redesign.

The problem is that the temperature sensor is in a sealed compartment close to the body of the motor, under the touchpad, which itself is under the touchpad cover. The result of this design is that the massive, metal body of the motor acts as a heat reservoir and the temperature sensor is sealed off from contact with the outside air.

Using electronic thermometers, and with the motor having been shut off for two hours, I measured the air temperature at 25 degrees, the temperature next to the motor at 32 degrees and the temperature under the touchpad cover at 35 degrees. The temperature in the sealed compartment under the touchpad and closer to the motor was presumably even warmer. Over the next two hours the air temperature rose to 36 degrees, the temperature next to the motor rose to 37 degrees and the temperature under the touchpad cover rose to 40 degrees. I checked the motor every 15 minutes, but the freeze guard never turned the motor on.

My only options are to install an external controller (with freeze guard) and the EcoTech EZ Interface Adapter Kit (at a cost of over $600) or to reprogram the pump to run continuously whenever temperatures are below freezing. U.S. Motors recommended the extended run times, which had been my conclusion also.

 

[bobodaclown]

Interesting info. Thanks for the update. Instead of extended run times what about shifting to the evening/night when freezing is more of the issue? Lowest flow rate/longer run time?

What about modifying the sensor location wire it to be away from the board/compartment?

 

[Chuck_Davis]

I've been running from 5 PM to 7 AM at 45% (the minimum required for my water feature). We have a day upcoming that won't get above freezing, so I'll have to run for 24 hours and then change the programming back. Kind of an anal trauma.

The temperature sensor is just a chip soldered somewhere on the controller circuit board. My suggestion to U.S. Motors for the redesign was a jack on the side of the controller box for an (optional?) 15-20 foot cable with the sensor on the end.

 

[bobodaclown]

Yeap, it's a screw job. Good recommendation on your part.

 

[mas985]

I don't rely on automated freeze protection myself and I usually recommend that others don't as well. That is a particularly poor design but other implementations have flaws as well.

If you are interested in other means of freeze protection other than running the pump, then you might want to start with this post:

http://www.troublefreepool.com/threads/86914-The-Physics-of-Freezing-and-Freeze-Protection

I am also willing to brain storm with you on other options as well as assess your risk for freeze damage. In many cases, people use freeze protect well before there is even a possibility of freeze damage and when there is a possibility of freeze damage, there are much better ways of protecting the equipment than relying on the pump.

 

[Chuck_Davis]

Hi Mark,

Very interesting article on freeze protection. It allayed a lot of my fears (down to a certain temperature, at least.) I'll gratefully accept your offer of some brainstorming, however.

While I don't want to spend money unnecessarily, I'm not too concerned about running the pump for some extra hours. I normally run 6-8 hours per day in winter anyway, so adding in some overnight hours and the occasional day with freezing temps isn't a big hit. I'm able to run the VS motor so much more efficiently than my 2-speed that it paid for itself in less than a year. The biggest hassle is having to manually reprogram the motor based on temperature.

When temperatures don't go below freezing at night, I've been running the pump 3-4 hours in the afternoon and 3-4 hours in the morning, partly out of habit and partly to get the visual of the water feature when my wife and I are more likely to see and enjoy it. (Based on some prior freeze damage, which I'll explain below, I've been hesitant to turn off the water feature.) This overnight off-time gets me close to your 10-hour/20-degree limit for 1.5" pipe.

On and around days when temperatures are forecast to be below freezing at night, I've been running the pump from 5 PM to 7 AM.

Here are some pictures which will help provide some context:



(The capped stub that you see next to the foundation used to be the connection to the slide. There was a 2" valve with 1.5" bushings. Until last winter the valve was closed and the pipe was drained during winter. Last winter we experienced some temps down around 5-10 degrees, with several days when the temperature didn't get much above 20. Even though the (old) freeze guard had the (old) pump running, there was enough "dead" water between the manifold and the valve that the water froze and cracked the valve and the bushings. That demonstration of power has left me a little snake-bit about freeze damage. This is why I'm hesitant to turn off the water feature, which is the valve next to the stub.)

My pool equipment shelter has a metal roof and open slat wood sides, and is tucked against a corner of the house. There should be little radiative loss and greatly moderated wind. The pipes going to the pool extend beyond the equipment pad before turning underground. The pipes are not buried very deeply.

Referring to your article, it would seem that up to 10 hours and down to 20 degrees, maybe with some early morning pump run time mixed in, I should be OK. Your thoughts?

Beyond 10 hours and/or below 20 degrees, I could just keep the pump running. Luckily such extended cold weather is fairly unusual in Central North Carolina. I did have another thought, however, either as the primary approach for super-cold weather or as backup to the pump.

My equipment pad is around 3 feet above the pool. This has caused challenges, but it could possibly be turned into an advantage. It would seem (and could be tested) that if the pump were turned off and the multiport valve on the filter were cracked open that the system would pretty much drain itself dry. The check valve in front of the pump slows, but doesn't stop, draining. The only areas where I would expect water to remain would be the pump filter basket, the pump itself and the filter. I could hand-bail the lint basket on the pump and, if necessary, drain the filter.

What would be your thoughts for dealing with occasionally extended stretches of cold weather and/or occasionally under 20 degree temperatures?

Thanks in advance for your brainstorming.

 

[mas985]

Last winter we experienced some temps down around 5-10 degrees, with several days when the temperature didn't get much above 20.

Multiple days below freezing are always going to be an issue but under those extreme conditions, you are much better off draining the pad equipment of all water to prevent damage. The low temperatures also help prevent algae so you really don't need to run the pump anyway. Also, leaving ALL valves in a fully open position helps to relieve internal pressure of the ice expanding so when the pipes do freeze, they are far less likely to break.

Referring to your article, it would seem that up to 10 hours and down to 20 degrees, maybe with some early morning pump run time mixed in, I should be OK. Your thoughts?

Those numbers are for a fully sky exposed pipe in the wind. If the plumbing is sheltered and not exposed to the sky or wind, freeze times are much longer. For example, the plumbing should survive 0F for 12 hours, 10F for 17 hours or 15F for 22 hours. Do you remember the date when that pipe broke or the temperature/time conditions? I just want to make sure it was during an extended event.

My equipment pad is around 3 feet above the pool. This has caused challenges, but it could possibly be turned into an advantage. It would seem (and could be tested) that if the pump were turned off and the multiport valve on the filter were cracked open that the system would pretty much drain itself dry. The check valve in front of the pump slows, but doesn't stop, draining. The only areas where I would expect water to remain would be the pump filter basket, the pump itself and the filter. I could hand-bail the lint basket on the pump and, if necessary, drain the filter.

This would work for any distance from the pool as long as the exposed equipment is above water level. This will definitely prevent freeze damage even if a little water is left in a pipe. Ice is only about 10% larger in volume than water so technically, you don't need much air to prevent damage.

But another method you can use is to add a heat source which will pretty much eliminate any remaining risk but it too relies on power. But the difference here is that the extra heat source heats up not only the equipment but also the concrete pad and surrounding walls. These are pretty good heat sinks/sources so should the power fail, the heat will carry over for some time and most likely prevent freezing much longer than a pump that has stopped running. So I much prefer this method over running the pump.

Just remember that running a pump to prevent freeze damage is also taking a risk because the pump can stop running for a variety of reasons as is often described by members on this forum.