EK1 Near Limit Aquastat

NEMatt

Had my 12 yo Energy Kinetics storage tank lower seam give up the ghost yesterday and plumbed in a typical AO Smith 100 as a replacement.

All connections are essentially as they were with the prior EK tank with minor differences for nipple placement and tank height etc.

I wired the tank to bypass the heating elements and run heating calls off that lower thermostat.

It seems to me like the boiler is running nearer the high limit during a domestic heating cycle now before the heating call extinguishes.

I assume there might be two causes... 1. Dip tube. 2. Lower tstat placement.

Any thoughts from @Roger or other EK gurus?

HVACNUT

Use the upper thermostat.

NEMatt

https://forum.heatinghelp.com/discussion/comment/1899246#Comment_1899246

Wouldn't that make it even worse?

In my mind the long dip tube is just pumping water that just left the PHE right down near the tank drain where it gets sucked back up into the PHE. That just gets hotter and hotter without ever really stratifying in the tank. Seems like it would take even longer for the upper stat to reach the setpoint than the lower one which is closer to where the tube is dumping hot water.

109A_5

If the boiler is running at a high temperature during a DHW call / recovery I would think the overall heat transfer efficiently is not as good as the former tank. Maybe the dip tube need to be shorter like in the picture. Was the dip tube length of the new tank matched to the old tank ?