Getting more hot water from my solar heater—what am I missing?

Getting More Hot Water From My Solar Heater—What Am I Missing?

“I’ve seen people get so caught up in adding insulation or tweaking settings that they don’t even check if the circulation pump’s actually running.”

That hits home. I spent a weekend messing with insulation and timer settings, thinking I was being clever, only to find out my pump wasn’t even kicking on. Turns out, there was a loose wire at the relay. Felt pretty silly after all that troubleshooting.

About the temp sensors—yeah, I’ve had one drift out of range before. The readings looked fine at first glance, but the water was way cooler than it should’ve been. Swapped the sensor and things went back to normal. Now I check the digital readout against a cheap thermometer every few months, just in case.

I do run a small electric backup, but honestly, it barely keeps up if we have extra people staying over. Our system was sized for a family of three, but with guests, it just can’t keep up. I guess that’s one of those things you don’t really think about until you’re halfway through a cold shower.

Sediment hasn’t been a huge issue for me, but I did flush the tank last year and got more gunk out than I expected. Not sure it was enough to block flow, but it definitely made me rethink how often I should be doing maintenance. Hard water probably doesn’t help.

Funny how it’s always the “simple” stuff that gets overlooked first. I’ve started making a checklist for myself—pump, sensors, breakers, and then the bigger stuff. Saves a lot of time (and frustration) in the long run.

Been there with the “why is this water so cold?” moment, usually when I’ve just shampooed my hair. Here’s my quick-and-dirty checklist for solar hot water woes: 1) Check the pump—sometimes a good whack gets it going, but maybe don’t take my advice on that. 2) Sensors—yep, those things lie more than my old bathroom scale. 3) Flush the tank—gunk builds up faster than you’d think, especially with hard water. 4) Backup heater—if it’s undersized, you’re just delaying the inevitable icy surprise. I swear, half my “fixes” are just me discovering something unplugged or switched off...

That checklist covers a lot of ground—I’ve definitely had my share of “why is nothing working?” moments, only to realize something as basic as a tripped breaker was the culprit. I’m curious, though, have you ever looked into the orientation or tilt angle of your solar panels? I’ve read that even a small change in angle can make a noticeable difference, especially during winter months when the sun’s lower. Also, does your system have a mixing valve? Sometimes those can malfunction or get set too low, and suddenly you’re in polar plunge territory.

One thing I ran into: after a few years, the insulation around my pipes started to degrade, and I was losing a lot of heat before the water even reached the tap. It wasn’t obvious at first, but fixing that helped more than I expected. Wondering if that’s something you’ve checked—or if there are other sneaky culprits you’ve found in your setup?

I get where you’re coming from with the panel angle, but honestly, unless your panels are way off or you’re in a spot with extreme seasonal sun shifts, I’ve found the gains from tweaking tilt are usually pretty minor compared to other issues. In my experience, sediment buildup in the tank or collectors can be a bigger culprit for lost heat—especially if you’ve got hard water. I’ve seen systems lose a ton of efficiency just from scale. Pipe insulation’s important, but if you’re still not getting enough hot water, I’d check for flow restrictions or partially closed valves too. Sometimes it’s the simple stuff that gets overlooked...

- Good call on the sediment—hard water’s a pain.
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“Sometimes it’s the simple stuff that gets overlooked...”