Solar Water Heater

I just bought a new home not long ago and it came with a solar water heater. I know absolutely nothing about solar water heaters. The tank looks old and rusty but the panels on the roof don't look to be in bad shape. The water seems to be heating ok but this morning there was no hot water. I don't know it takes awhile for hot water to return into the tank, or there is something wrong with the tank its self. I am thinking about replacing the tank because it looks rusted and in need of a replacement. How much would a new solar tank cost? does it need to be a special solar specific tank, or could i get a regular tank from Home Depot? Thanks.

I read that you can build your own solar water heating system for about $70, so I doubt there is anything special about replacing the tank.

These systems usually have a ton of hot water (almost to boiling!) running through them and should kick over to the house's normal hot water system if it runs out, but if there is rust, there might be some corrosion that is preventing the water from entering the tank. I'll put out some feelers and see if I can find out more for you.

Adrienne

Ya it may cost around 70 to 100 $ you can clean rust instead of buying new one.

Ya it may cost around 70 to 100 $ you can clean rust instead of buying new one.

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I agree with Tasha. You can clean rust so before spending money on the tank, try and clean it first. If the problem still continues the rather take a picture of it post it on the forum.

Hey, post up some pictures of that bad boy. Where I live in Chicago I haven't seen one of these setup yet. Is it a real eye sore? I can't imagine it would cost that much, below is a link from EnergySavers.gov on proper maintenace of a solar watr heater.

Energy Savers: Solar Water Heating System Maintenance and Repair

SWH systems are designed to deliver hot water for most of the year. However, in winter there sometimes may not be sufficient solar heat gain to deliver sufficient hot water. In this case a gas or electric booster is normally used to heat the water.

For "$70" ou can make something that would heat up some water but I doubt you'd get far into a proper domestic hot water system. A more reasonable price for a complete SHW system is $2 to 6 thousand. One example

But the rust on your tank is most likely cosmetic. A typical solar hot water storage tank is much like a regular hot water heater but without the heating elements (electric) or gas burner and heat exchanger (natural gas). And the typocally have two more connections for water going to / from the solar panels or heat exchanger.

The "tank" is typically a steal tank, coated in the inside with something like porcelain. Then covered with insulation and that is covered with a thin sheet metal - this is the white skin you can see when you look at it. This can rust off entirely and will not affect the tank (although if it's getting wet enough to do that you do have some other issues going on).

Like most all hot water heaters there is an "Anode Rod" which is there to slow the rust process. You should replace this rod (it works by rusting first - once it is rusted the rest of the tank will rust more quickly).

Now - why didn't you have any heat? Several reasons come to mind - not all apply to all systems:

• You're system has a clock (usually to turn of or "drain down" at night) and the clock is wrong because of a power failure or something.
• It was too cold where you live yesterday - if it is below freezing some systems will not operate (this prevents bursting pipes on the roof).
• Blown fuse or circut breaker - although the heat comes from the sun most systems use some electricity to pump the water to / from the roof.
• It has been cloudy were you live for a few days - even the best solar systems can only store heat for a couple of days.
• You solar panels are dirty - probably not the cause since this happens slowly, not over night but still wash them.
• There is some kind of "thermal loop" - this happens when the tank is lower than the panels (this is typical) and the hot water from the tank rises into the panels at night - cools off and falls back into the tank. There is almost always a valve to prevent this but sometimes it can stick open.
• Your pump has failed. They do wear out.

So I suggest you find a plumber who specializes in solar hot water systems (there might be a name on your system) and have them come and examine your system. You have two particular questions for them:

1 - why isn't the solar hot water hot

2 - why didn't the backup system (whatever it is) turn on.

In my house I put a switch in the backup system so it will not come on during vacations when I turn the whole thing off. Might (hopefully) be something simple like that.

But it would be good to find a plumber who likes to work on your solar system now because if you need one in a hurry (and ALL water heaters fail eventually) you'll have one.

Good Luck,
Frank

There are many benefits to owning a solar water heater and the best one is that the energy of the sun is endless, sufficient and free of charge. Hence, we can easily get hot water anytime we want without paying anything.