Solar freeze?

[mkelley]

Anyone got any weird ideas about this one?

During our recent freeze night (the one night where it actually dropped to freezing here in central Florida and folks reported ice from drippy water outside) our pool pump, as is normal, came on in "emergency" freeze protection mode. That's to recirculate water so it *doesn't* freeze in the pipes.

When that happened water started coming down off our roof and in going outside it was apparent it was coming from one of the solar panel areas. I couldn't see too much that night (nor, in that temp, did I want to try and investigate more :>) so I just let it leak. It did drain some amount of water out of the pool but I replaced it with a drippy hose at the same time.

The next morning there was an ice trail down from the top of one of the panels where the water had pretty obviously leaked out of. So I called the solar company and they scheduled someone to come out this week to take a look at things.

In the meantime I had shut off the water to the solar system, but I forget (old) that the automatic scheduler would simply turn it on the next day. Which it did... and there was no more leak.

At first we weren't sure the water was circulating through the panels, but after a few days it's obvious it has been, with no leaks. I am left with no particular explanation as to what could have happened.

My speculation runs from anything like there is some sort of automatic freeze value that popped out that night (and went back to normal) to a self-healing pipe (hey, my wife believes in miracles). But I'm not going to spend $140 or so (the solar company quote) just to have someone come out and look at something which doesn't appear to be, at the present, broken.

Does anyone have some real knowledge as to what was going on here? These are FAFCO solar panels if that helps.

[CarlD]

Sounds like a lot of frozen condensation that then melted off.

[mkelley]

Well -- don't think so. For one thing, this only started when the pump came on. For another -- the water was *pouring* off the roof (I actually told my wife it was raining, the water was coming down so hard). And finally, this all lasted about 12 hours (until the next morning when the freeze warning was over and the pump stopped).

Then again -- in Florida we do have lots of condensation -- could this possibly occur for as long as 12 hours? Something to do with the cold and the warmth of the roof, perhaps?

But I appreciate you at least giving me your take. Hopefully there will be some others (maybe from solar installers?)

[ChuckD]

Any chance there's some kind of pressure relief valve that might have frozen open? Or how about a drain-back valve that opens to allow drainage when not in use? It might have frozen open, and then when the pump came on simply stayed open.

Chuck

[mkelley]

Yeah, that could be it -- unfortunately, the solar company that installed the system went out of business six months ago (the company I contacted is carrying the warranty on the panels but knows nothing else about my system) so unless I pay money to have someone look at it I have no real idea.

But I like that theory -- although where the water was coming from seems somewhat unlikely considering it was on the piping on one of the middle panels (I'm far from an expert here, but I wouldn't think anything like those valves would be installed somewhere arbitrarily in the middle sections but perhaps that's *exactly* where it would be installed).

I'm guessing at some point (assuming all stays well in the immediate future) I'll have occasion to have some repair work done and at that time I'll ask whoever knows about these things what could be the case up there. OTOH, perhaps it truly is a leak that is just waiting to happen again...

[JohnT]

My first guess would be similar to the above. You probably have an air bleeder at the top that was either a little sticky from the cold or had water frozen in it already

[Poconos]

Something else to be aware of is that a solar panel can freeze pretty fast. They are designed to be good solar heat absorbers, and therefore become good heat radiators. Quite possibly, looking at a cold clear sky at night, some water froze and when the pump started a chunk of ice jammed the bleed valve. However, I think the ice should have melted pretty quick and let the valve close properly. It is quite possible the panels hit freezing before the temp sensor on the freeze protecton circuit caused the pump to start. I'd just be aware this problem happened once and simply keep watch to see if it happens again.
Al