Join Date: Feb 2015
Location: Cottage Grove, MN
Something is wrong with that heater.
What was the BTU of the hot water boiler unit? Most of those are around 30-45K BTU. The hanging type, right? Those forced air hanging type heaters are supposed to heat as fast, if not faster than the other types of heat. I had one in my old shop which was 26'x36' 9' ceilings, well insulated and If it was 50 degrees in the morning when I walked in I had 72 in about any hour. 12'x8' overhead door, lots of windows, etc.
So, that guy needs to come back and see what's up. If you look from the back can you see that the entire burners are lighted? Maybe something is plugged in the burners. It just sounds to me something is not firing properly.