USING A TEKMAR 156 FOR MY EKO WOOD BOILER & BACK UP PROPANE GOT SETTING QUESTIONS????

Any one out there use this control. My 500 gal tank storage gets up to 150' F and then doesn't call for any more heat transfer into it even though I remember it getting upwards of 165'. Can anyone help me with the storage setting to reach my goal in terms of set temp and in consideration of set points and differentials?? Email me at mouchey3@comcast.net
I use a TEKMAR ?260 as my master control a Tekmar 156 to do the heat transfer to storage and (2) tekmar 150's one for the wood boiler and one for the propane boiler. I prioritize my hot water through the 260.
Thanks you guys are always so helpful it's the start of my 2nd year with our EKO25.
Mary Jane