I'll bet the pipes from the boiler to the Amtrol take never got primed.
I'll just start from the beginning. The Amtrol tank has a thermostat switch in it. It's either machanincal ( a hand turned dial with numbers) or digital (red LED numbers on a little screen). If it's the mechanical one, set it to 4 or 5 to start. That will make the water about 120 degrees. If it's digital, you must read the instructions as it's a bit complictaed. If the water in the tank is less than 120* the witch closes turning on the pump. If you're doing it by hand you can put a seperate switch on the pump, but the thermostat must be calling for heat or the pump won't run. It's hard to tell if a pump is running, you almost have to use an ammeter to make sure.
When the amtrol is calling for heat, the pump will run no matter what the temperaute of the boiler is. Once the boiler is above 120* it will transfer heat to the water tank. Typically the boiler would be around 180*, but I'm sre it would work with it being 160. If the boiler is much below 160 it'll take a long time to heat the tank. I don't think the speed has much to do with it unless it was too slow. I'd think there's no such thing as too fast. The whole idea is to keep the coil in the water tank up to the temp of the boiler.
So, get the boiler to 160-180, make sure the Amtrol tank is calling for heat, verify the pump is running & you should make hot water.
No hot water problems:
1: Pump is running but not pumping. Could be the pump is bad, could be it was not primed. You must add a valve and a boiler drain so you can take a garden hose and force water through the loop. This only needs to be done once in it's life, but if not done, the pump will not pump. You close a valve, open a boiler drain & purge the air from the pipes.
2: Coil inside Amtrol is plugged. Very rare, must be cleaned with an acid flush.
3: Boiler not hot
4: Bad thermostat. Verify that pump is getting power.
5: No water in Amtrol tank....fill that bad boy!