# What to cover backflow preventer with on cold night?



## Green (Dec 24, 2017)

...other than a blanket, anything else that works well?
Anyone remember those "emergency space blankets"? I was thinking maybe something like that would be in Home Depot for this purpose (insulating pipes).


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## ABC123 (Jul 14, 2017)

I drain my supply line from inside the house with the water turned off. Then I cycle a zone to allow the other side after the backflow to drain by gravity. Doesn't take too much work but watering just once a week right now.


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## g-man (Jun 15, 2017)

I researched of using something like this. Frost King HC3A Automatic Electric Heat Cable Kits, 3ft x 120V x 7 Watts/ft, 3 Feet, Black https://www.amazon.com/dp/B000IKSQ8U/ref=cm_sw_r_cp_apa_hhhZBbHM8GK1B


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## Green (Dec 24, 2017)

ABC123 said:


> I drain my supply line from inside the house with the water turned off. Then I cycle a zone to allow the other side after the backflow to drain by gravity. Doesn't take too much work but watering just once a week right now.


I could do that. Is this a better approach, or does water still tend to stay in parts of the backflow assembly, still necessitating covering it to insulate?


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## ABC123 (Jul 14, 2017)

Green said:


> I could do that. Is this a better approach, or does water still tend to stay in parts of the backflow assembly, still necessitating covering it to insulate?


It's just what I've been doing to make sure it won't be an issue as mines copper. Copper doesn't insulate very well, seen 24* a few nights already. I'd imagine some type of insulation would aid in keeping it warmer but any gaps of insulation might leak all the heat.


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## Green (Dec 24, 2017)

Last night hit 32 or so, maybe colder, for like 4 or 5 hours. I just programmed it to run for a few minutes each hour during the freeze period.

We have a couple of nights in a row later this week that will hit 28 or so. I think I'm going to drain it, and then run a down hill area for a minute to get extra out, as mentioned above...and then throw a plastic tarp that's folded in half over the pipes, and anchor with a couple of bricks.

I have to water another area tomorrow morning...it's been over a week since it rained significantly...so it's good the thing is still open.


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## Wlodyd (Aug 27, 2018)

Look up "pipe insulation" for the actual lines and "fiberglass plumbing pipe wrap insulation" to the BFP itself. You can wrap that over oddly shaped objects and duct tape it. Leave it on as long as you'd like.


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## JDgreen18 (Jun 14, 2018)

ABC123 said:


> Green said:
> 
> 
> > I could do that. Is this a better approach, or does water still tend to stay in parts of the backflow assembly, still necessitating covering it to insulate?
> ...


When you cycle a zone are you hooking up your air compressor to provide back pressure? If not what would push the water out


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## Green (Dec 24, 2017)

JDgreen18 said:


> When you cycle a zone are you hooking up your air compressor to provide back pressure? If not what would push the water out


Good question. I assume the idea is just to drain the exposed pipes to get most of the water out so if they start freezing, the slush or ice in it does not expand so much as to damage the valves in the backflow assembly.

@JDgreen18 The lines are in the ground surrounded by warm soil, and much warmer than the air temp, so no worries about those freezing yet.

@ABC123, is this correct? Are you on a hill? I am, and could see this method working.


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## Green (Dec 24, 2017)

Wlodyd said:


> Look up "pipe insulation" for the actual lines and "fiberglass plumbing pipe wrap insulation" to the BFP itself. You can wrap that over oddly shaped objects and duct tape it. Leave it on as long as you'd like.


Will do, thanks.


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## Green (Dec 24, 2017)

g-man said:


> I researched of using something like this. Frost King HC3A Automatic Electric Heat Cable Kits, 3ft x 120V x 7 Watts/ft, 3 Feet, Black https://www.amazon.com/dp/B000IKSQ8U/ref=cm_sw_r_cp_apa_hhhZBbHM8GK1B


Cool. Might be useful for someone.


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## JDgreen18 (Jun 14, 2018)

@Green yes but I tried this without hooking up an air compressor and Im not sure it did anything...by creating back pressure and just draining a little water out of one of the zones I would think this would be enuf to drain the back flow. Does this makes sense


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## Green (Dec 24, 2017)

JDgreen18 said:


> @Green yes but I tried this without hooking up an air compressor and Im not sure it did anything...by creating back pressure and just draining a little water out of one of the zones I would think this would be enuf to drain the back flow. Does this makes sense


Makes total sense. That said, I have a drain valve in the basement, so I can get the water out of the main supply line. So, less water than normal if everything is opened up. That should help when combined with some insulation. I just wonder how much it helps.


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## Pete1313 (May 3, 2017)

I just use a blanket draped over the top of it to trap some of the heat from the soil as soil temps are still in the low 50's. Here are some of the temps northern IL saw Sunday morning. I ran an irrigation cycle on Sunday evening. I think low 20's is pushing it for the blanket, and should have drained it, but had no issues. I knew if I had a break, the hydrawise with flow sensor would alert me and I would have to sweat in some new pipe. It works but go at your own risk.


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## ABC123 (Jul 14, 2017)

Yeah it was the furthest zone I had down hill. I'll be blowing it out with a compressor when it's time for winter.


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## ken-n-nancy (Jul 25, 2017)

Pete1313 said:


> I just use a blanket draped over the top of it


I do the same with an old blanket. Just preventing radiant heat loss (avoiding a clear view of the sky) makes a huge difference in overnight frost events.


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