I have a new Buderus hot water boiler. Recently there is a butning antifreeze smell when it fires. Its worse if it hasn't been on in a while. There is no water on the floor outside of it however I can't see underneath. There is glycol in the water. It doesn't matter what zone is on. The boiler did overheat 2 months ago because the brand new aquastat malfunctioned heating water to 235. Any ideas?

Burning not butning

Hi Eon and welcome, It sure sounds like a leak, I would have the installer back in to check.