# How to flush water heater that has solar panels



## Homerepairguy (Aug 1, 2010)

Want to flush our water heater that has solar panels attached. Procedure I want to use for the flush is:

1. Turn off electricity. Turn off cold water to heater and open a hot water faucet.
2. Drain heater completely.
3. Turn on cold water to fill heater about half way to loosen sediment.
4. Repeat steps 2-3 until water runs clear.

My questions deal with the solar panels. When I drain the heater, the water from the solar panels will drain out. I could prevent that by shutting off the two ball valves that are in the lines to/from the solar panels. But if I do the flush during the day, I'm afraid of the thermal expansion issues in the closed loop to the panels. (I prefer not to do the flush at night if possible.)

I would like to just let the water drain out of the solar panels but then I don't know the procedure to bleed the air out of the panels after the flushing is complete.

Here's the valve setup to the solar panels:

Water Heater >--->pump>--->ball valve>--->hose bib>--->solar panel1>---,
Water Heater <----------------<ball valve<---<hose bib<---<solar panel2<---'

What's the correct procedure to use? How do pros do water heater flushes with this type of setup since they would be doing it during the day? I would like any responses on how to bleed air out of the solar panels to come from trained folks and not best guess from untrained folks.

Thanks,
HRG


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## Bondo (Dec 8, 2007)

> My questions deal with the solar panels. When I drain the heater, the water from the solar panels will drain out. I could prevent that by shutting off the two ball valves that are in the lines to/from the solar panels.


Ayuh,... I've never seen a solar system that sends the Domestic water to the roof,...
They use antifreeze in the solar loop,... domestic water heats in the tank...

got a picture,..??


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## Homerepairguy (Aug 1, 2010)

Bondo said:


> Ayuh,... I've never seen a solar system that sends the Domestic water to the roof,...
> They use antifreeze in the solar loop,... domestic water heats in the tank...
> got a picture,..??


It never snows or freezes in our area so potable water in the water heater is heated directly by the solar panels. The connection for the drain faucet at the bottom of the heater has a "T" connection. One side goes to a hose bib and the other side goes to the pump shown in my previous diagram. For absolute confirmation that potable water and not antifreeze is used, when I open either hose bibs shown in my diagram, water comes out, not antifreeze.

Guess only folks who live in the southern portion of the U.S. where it never freezes would be familiar with the solar setup we have.

Thanks for your interest,
HRG


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