Necessary to drain solar panels in Northern CA

[bbrock]

Hi,
I have been meaning to post this prior to the Fall, but better late than never. I will try to post pics later of my basic solar system. I have a 1 story home with the original solar panels on the roof (not sure which previous owner installed them). We live in in Alameda County, which is the East Bay of San Francisco. Per the average winter temps, temps could dip to the high 30s, but I assume this would be a rare occurence, and for not too long. Basically, I am curious if I need to drain my solar panels? I don't see any drain valves or ways to drain my system. Hopefully, you all will be able to help after I get some pics uploaded.

 

[chiefwej]

I don't know about yours, but in my system the panels drain every time the system shuts down.

 

[jblizzle]

Mine also drains whenever the solar is off so that the panels are not damaged from "superheated" water softening the plastic and the vacuum created by the weight of the water.

I also have a drain valve that I open in the winter (no point in running the solar) to be sure that they are empty so there is no chance of freeze damage for the few nights it actually gets cold.

 

[Chuckiechan]

Probably not where you live - Alameda is unlikely to even get frost, let alone freeze, but it's a good practice to drain them anyway.

Mine drain anyway per design, but I also set the electric valve not no close all the way to speed up the draining to avoid the funny noises it can make.

 

[mas985]

As long as your panels are self draining, they should be fine.

 

[bbrock]

I just now saw these replies. I don't know why I was not emailed about replies when I have been emailed from my other posts. That is a side issue I will have to work on.

Anyhow, I will read through the replies, and I have pics to post.

 

[bbrock]

As for the self-draining, whenever my pump turns off I too hear the solar drain. This is the case even if my solar automatically turns off during the period my pump is running. So, I guess it automatically self-drains. I just went out there now. Turned pump off. I heard it drain and pulling air in through a valve at the top. Therefore, I probably don't need to drain the system then. Right?

It is strange though that the solar is running as long as it is right now in the Fall, even when the sun is not directly on the panels as it was in the summer. This is our 1st Fall in our home, so I am learning the patterns. To verify the system was working, I turned the actuator valve from its on position to the opposite end, and it turned off solar. Also, I switched it from AUTO at my solar control panel (the setting I normally leave it on), to OFF, and it responded and shut off the solar. Therefore, I know it is working.

Here are some pics:
This is my solar control panel. I have in Auto Mode. Should I just leave it in this mode for all seasons?

This is the valve at the roof that I hear air get pulled through when the pump turns off.

 

[bbrock]

One new thought I had was is it actually even necessary in California/Alameda County to even bother turning off the solar? I was thinking why don't I just leave it Auto every season. For one thing, it would be circulating water which would curtail any freezing (but, I'm not even expecting freezing temperatures here), and also it would partiall heat the pool for those polar bear dips I want to take, and lastly, I don't think it would be putting any more strain on my system than normal. Please chime in anyone, specially you California residents. Or, better yet, Mas985 because you're in the same County. Tx

 

[ping]

I don't turn off my solar. We use the spa a lot during the winter so the gas heater does not have to work quite as much if we leave the solar on auto. I also believe that things last longer if they are used rather than sitting.

If you turn off the solar then you should use a little less chlorine as the water will be colder.

 

[bobby1017]

Mine only turn on when the solar temp is higher than the water temp, so they would run during the day but be off at night, even when the freeze protection comes on no water would go to the panels. I guess I could set the valves to stay open all the time maybe. I turn mine off for a few months, since it never gets warm enough to swim, why burn the power. The panels drain by themselves but there is always a little water left so I do remove the plug in the low corner of the panels that way any water left drains. I know last December we had at least 14 days where the overnight low was in the high 20's and the low was 20, raised heck with my citrus trees. Also I have noticed frost on the panels before anywhere else, I guess since they are elevated and air circulates they get cool faster, I see your are on your house which may help keep them warmer. Looking at Accuweather for Livermore last December there were a few night's in the upper 20's and many in the low 30's.

 

[bbrock]

Thanks for the replies. I don't know why I am not getting notifications about responses any longer. I looked in the settings but I don't know what to adjust. Additionally, I don't know why my pictures from Flickr are not showing any longer. Does it have to do with the permission of a photo? I'm not sure if the photos need to be set to public, friends, family, friend & family, or private. Clueless again.

 

[jblizzle]

Did you change the name of the Flickr folder? Or move the pictures? That could break the link. I would think they need to be set public.

For notifications, if you go to Settings (under Pool School) and then General Settings on the left, you can change the default subscription method ... that will change any new threads/posts you make.

If you click the link to view subscribed threads, you can change the notification settings for any/all of those threads.

 

[mas985]

(but, I'm not even expecting freezing temperatures here)

How long have you lived in the area? It definitely gets below freezing (down to 25F) here but usually not long enough to start busting pipes unless you have very thin <= 1" pipes. Larger pipes will take much longer and/or much colder temperatures. Also I don't run solar in the winter. No reason to.

Another thing is that I would never rely on just freeze protection should it get really cold. At that point, I would drain the pad equipment so there is no possibility of freezing. But so far, I haven't ever needed to do that.

 

[bbrock]

Mas985, I have only lived here 8-9 months. Didn't know that about the temps. Sounds like I should then turn off the solar.

Jblizzle, I'm going to mess around w/ the Flickr photos to see if I can get it to work.

 

[chem geek]

Solar is not the same as regular pipes. It is intentionally not very insulating so the risk of freezing with any standing water in them is higher. That's why most solar companies recommend stopping their use in the winter and opening them up to fully drain them. That's what I do each year. The risk is low, but it is real and they have reported several cases of damaged panels from not essentially winterizing them. Nevertheless, in our area freezing is pretty rare and as Mark indicates rather brief. We're still running our panels now as we are supplementing with gas, but we'll likely winterize them in a week or two and just use gas from here until spring.

 

[bbrock]

Tx Chem Geek. I was thinking of turning it off by Dec. 1st. That could be my annual "turn off" date. I hear the system drain ea. time I turn it off, but I don't believe I have any special/separate valve/port to open to facilitate any further drainage. What would that valve/port look like? Where would it be? Is it obvious or show in any of my pics (I could try to post a few more solar pics I took that same day).

 

[mas985]

You shouldn't need any additional drainage ports unless there is a location where water can get trapped (i.e. local low spot) and only then would a local drain be required at that spot. As I said before, I have had my panels for 9 years and just relied on self draining to prevent freeze damage. I don't even have shut off valves except for the solar valve itself.

 

[chem geek]

I have our solar panel people turn it off only so that they can inspect it on spring startup at which point they plug any leaks or do other repairs at no extra charge. In practice, you could probably do it yourself as Mark does.

 

[pooladdict]

I just drain mine, then undo clamps at bottom and blow out lines. I am in an area that gets 2 months of minus 20c weather. My pool normally freezes 30-45" thick. I have never had zero issues.

 

[bbrock]

Tx Mas985, Chem Geek, and PoolAddict for the last few posts. I appreciate all the info.

PoolAddict, sorry to get grammatically technical, but I think you mean "I have never had any issues." The way you wrote it is a double negative. I understood what you meant though. Tx. Fortunately, I don't have to deal with freezing pool water.