- That check valve issue is a sneaky one—seen it myself, and it’s easy to overlook. Good call on the gravity loop, since even a tiny bit of reverse flow can drop your tank temp overnight.
- Also worth double-checking for any uninsulated pipe runs, especially in crawlspaces or attics. Even a few feet of exposed pipe can bleed off a lot of heat.
- Panel angle matters, but I’ve found shading from trees or even vent pipes can be just as bad. Sometimes it’s not the angle, but something casting a shadow at the wrong time of day.
- If you’re using a controller, make sure the sensors are actually making contact—had one that was just dangling loose once and the readings were way off.
Panel angle matters, but I’ve found shading from trees or even vent pipes can be just as bad. Sometimes it’s not the angle, but something casting a shadow at the wrong time of day.
That’s a solid point about shading—sometimes even a neighbor’s fence can sneak into the equation. I’d also add that if your pump is cycling too quickly or not running long enough, you might not be getting full heat transfer. I ran into a setup where the controller was set too conservatively, so the panels never really got hot enough to make a difference. Worth checking if your differential setting is dialed in.
- Good call on the controller settings—seen that trip people up more than once.
- Shading’s a sneaky culprit, but I’d also double-check for any air in the lines or slow leaks.
- Sometimes it’s just a combo of little things adding up. Don’t get discouraged, you’re on the right track.
Sometimes it’s just a combo of little things adding up. Don’t get discouraged, you’re on the right track.
That’s spot on—these systems can be finicky. One thing I’d add: check the temperature sensors themselves. I’ve seen a few where the sensor slipped out of its well or got some corrosion, and suddenly the controller thinks the tank is hotter than it really is. Also, if you’ve got hard water, scale buildup inside the collector or heat exchanger can sneak up on you and cut efficiency way down. Worth a look if everything else checks out.
Can’t tell you how many times I’ve tracked a “mystery” hot water issue back to a sticky check valve or a half-clogged filter. It’s easy to overlook the little mechanical bits—sometimes they’re the real troublemakers. Give those a quick look if you haven’t already.
