Ergomax, boiler reset and mixing valves:

We are considering replacing our Amtrol WH-7 Boilermate with the Ergomax E23 with our Slant / Fin Victory VSPH 120. The Ergomax will obviously supply DHW, but it will also serve as a buffer tank to help prevent boiler short-cycling.

My questions are as follows:

1) Our boiler has an outdoor temperature reset control which maintains 150 – 180 depending on the outside temp. The control does have DHW priority which overrides the reset temp when there's a DHW demand. If the boiler loop is at the low end of the reset curve (150*) and we have 2 showers running, is our boiler large enough to supply the 2 showers and at the same time satisfy the 170* water temp in the Ergomax?

2) I have several choices for an ASSE 1017 rated Mixing valve- do you have a recommendation for any of the following manufacturers: Danfoss, Taco, or any others?

3) Is it bad practice to reset the boiler temp when used with a reverse indirect tank like the Ergomax?

4) How does the Boilermate Wh-7 compare to the E23? From a DHW perspective, the boilermate has been able to meet our DHW demands even with the reset temps. If the E23 and the WH-7 are similar in performance, we shouldn't have a problem.

Hope these questions make sense -