Okay, I have done some more checking and my 175,000 Btu Weil-McLain CG and the circulator pump only run when the thermostat calls for heat. The aquastat is set at 180 deg. but the thermostat is satisfied way before the water gets to 180 deg. Grossly oversized boiler? Should I turn the aquastat down and feed the water directly into my radiant floor at the lower temperature? or put in a smaller boiler and mix the water?

Thanks,
Kris

Need heat loss calc as your house may need the boilers output on the design days or the coldest windy nights. That boiler needs return water temps above 135 to keep from condensing...Eric

Do you know how your iced tea glass sweats in the summer? When you bring back low water temps (below 135-130) to a boiler (any boiler), the flue gases condense. This condensation is acidic and will eat cast iron, steel, and copper boilers (your boiler). To do most radiant systems you will require some sort of mixing device, albiet a valve(s) or variable speed mixing.

Yes, your boiler is oversized for your current system. If it never gets over 110* (previous thread) as you stated then it is running in a condensing condition. Temporary conditions are fine as long as they eventually get over the threshold, as the acids will burn off.

What are my options? Can I take out some burners in the existing boiler? Is there any option except buying the properly sized boiler?

Thanks,
Kris

Let me digress. I think I'm giving you bad info here. You're boiler may very well still be oversized, but you probably have much more radiation than required to heat the home. Let me explain:

If a room has a 3000 btu/hr heat loss, and you have baseboard that puts out 500 btu/hr at 170* AWT, then you need 6' of baseboard. However, if the room has 15' of baseboard, then it is going to satisfy the load with a much lower water temp. Thus the boiler never gets up to temp.

Usually with an oversized boiler the boiler goes out on high limit then cycles a lot.

You'd have to ask a Weil Rep about derating the boiler. Most any boiler can be derated 10-15% with gas pressure.

I can't seem to find your previous post buy you MIGHT be able to remove burners and plug orfices depending on the burner arrangment.
Most sectional radiation is oversized and runs a litle to cold for no mixing valve a non condensing boiler. most house are more weather tight than when they were built, and were built for gravity flow and 150* operating temp. I would consider a condensing boiler and constant circulation with a good thermostat or Tekmar 256...Eric