I have a smith gv100w boiler with fenwal controller. At TFI: the igniters glow yellow for a minute, but there is no gas and I get the 3-flash indicator of ignition failure. If I turn off the power, wait a few minutes, and try again, then it will sometimes start OK, and the burners stay on long enough to heat up everything, but once the reaches the target temperature and the burners stop, it won't relight on its own - I have to do the manual power off & wait a few minutes.