Thermosiphon pressure issue

[Inspector Gadget]

Had a bit of an issue today with the new woodstove. It's an Elmira Woodworks with a water jacket. 50 Gallon tank on the second floor. I've had several fires in it before, but today the pressure-relief valve on the hot water tank gushed a crapton of water.

Operating theory is that since the system is being fed from afar, that air was captured in the hot water tank and pressurized under heat, causing the issue.

Looking to touch base with thermosiphon folks to get a sense of their issues - if any.

 

[begreen]

Is there an expansion tank on the system? A sketch of the system will help diagonosis.

 

[all night moe]

If there is a expansion tank in the system, you could install a heat dump. If there isn't an expansion tank that would be the first step.
A heat dump would be an aquastat, water to air heat exchanger, and fan. Dump that excess heat into a usable area.

Just a thought.