thermosyphoning problem

 I am having thermosyphoning problems with my storage and panels.

I am running 550 sf of Energie Solaire panels, unglazed in Seattle.
I have 800 gallons of storage.

During the night, thermosyphoning is stealing heat from my storage.
Couple of sunny days will take my storage up to  140 degrees.

During the cold nights, the temperature of the panels will go up to 70
degrees on a freezing night  just with thermosyphoning.

I am running 1 " piping up to the panels.

I have no idea how many gallons a minute are running up the 40 feet to
the roof, but the incomming water is near freezing and I fear that it
is robbing me of heat.

I turn the valves of manually, during the night, but I am nervous to
do that because if I forget I am worried that my panels will get too
hot.

I have a taco pump and that does not seem to work.

The water flow is the same direction as heating mode.   I have been
having the hot return to the bottom of the tank and could switch the
coil direction so hot water comes into the top of the tank and add a
check valve.

Any suggestions?

Sleepless in Seattle

  On Sun, 6 Apr 2008 14:59:44 -0700 (PDT), AstickfortheMULE wrote:

 On Mon, 7 Apr 2008 15:19:05 -0400, I Poked Fuckahontas wrote:

 On Mon, 7 Apr 2008 15:20:20 -0400, Jay "Little Napoleon" Severson wrote:


http://tinyurl.com/yqm7bo

 On Mon, 7 Apr 2008 15:21:22 -0400, w wrote:


http://tinyurl.com/yqm7bo