Tue Dec 24, 2019

1" PEX pipe blew right at the stove outlet a year ago from running the stove without the circulating pump. The pressure relief did not activate, as the pressure relief was after the PEX pipe, and temperature did not rise much at the pressure relief.
This is a failure mode that needs to be eliminated by design, such as by using metal pipe and a hot water storage tank on the outlet - though this does not address the inlet side. Another buffer tank would need to added at the inlet side. Or, a warning light could be added to notify that the circulating pump is not running.
Automation controls should have a lockout for running the stove without the circulator pump.
Most redundant control would be a pressure relief valve added to the entrance side and the exit side.
Current design has the pressure relief after the PEX. The pressure relief should be right on the stove on a metal pipe connection, before any PEX.

Hydronic Stove Log