Has anyone tried using a smaller diameter line for the boiler protection loop? Use 1 1/4" for pipe to and from storage, but use say just 3/4" from the output tee to the thermic valve? Still put in the ball valve, but much cheaper for 3/4" materials than 1 1/4". 3/4" should be able to allow enough flow to satisfy thermal protection, (both corrosion and overheat), and because of the inherent restriction of the smaller pipe water shouldn't JUST go round and round if you forget to close it down. Plus, if you set your pump launch temp at say 160 with a 140 degree valve, thermic valve may be more responsive and charge storage quicker. Just a thought. Waiting for the Guru's to burst my bubble!