Boiler turns on everytime the air handler does.

Hello forum...I have a Weil McLain P-WGO-4 boiler running my Hot Water and my Air Handler (First Co. 48MBXR-4HW). The HW tank, air-handler, and boiler are all within a few feet of one another. I've noticed that the boiler turns on each time the air handler gets a call for heat. The temp on the boiler reads 160 before and after the unit turns on. Is there a way to add a thermostat so that the boiler will only turn on if the water temp in the air handler gets too low? Seems like that's how it should be.

Thanks,
Tim

Heat exchangers are often rated at 180-degree inlet. Now, will they work with lower temps, yes, but you might find the outlet temperature from the ducts is cool (common complaint with heat pumps). My guess is that the thing is wired to try to bring it up to 180 degrees when the air handler is calling for heat, and it may or may not ever get there depending on the load and the recovery rate of the boiler. Depending on the boiler, some can be damaged if the return water is too cold, so while you are extracting heat with the air handler's coil, if the boiler wasn't on, the return water might end up too cool and damage things. So, it could be normal and need to be the way it is...you probably could rewire it to work the way you want, but it may not work well. You'd have to do some more research.

Thanks for the reply and I certainly appreciate it. I went over to look at my neighbor's setup and it's identical with the exception of a relay system (Honeywell) for the circulators. I witnessed one of his three zones calling for heat twice and a second once then opening (as seen by the LED under the relay) before the boiler ever turned on. Is this box/PCB what I need?

A hot water radiator system is different than hydro-air. Cold air blowing on you in the winter is not pleasant. The only way to preven that is to have the water to the coil in the handler warm enough.