Anyone have experience with Buderus boilers?

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Swamp_Yankee

Member
Oct 18, 2018
76
Hunterdon County, NJ
I have a Buderus oil boiler with a 2107 Logamatic control box. It was put in by the previous owner of the house about 12 years ago, but I don't think it's really optimized for the house/heating system. I set set up a custom program, but its still not quite where I need it, and I could use someone who knows a lot more about these than I do to help dial it in. I called the installer and he's always booked up.
 
i've wired and setup a few. looks like your over the warranty period. they are not good with a claim. going thru the computer they have a bunch of different scenarios built in for just about any setup. when i would try to set up a boiler for the owners what i would be trying to do was usually already programmed into the computer. what are you trying to do?
 
Ugh, I had a bad experience with their customer service. I had a question about my indirect tank. It wasn't anything crazy, only asking what I could expect if I installed a smaller than recommended boiler to heat the water. They wouldn't answer a homeowner. I ended up calling and saying I was with Eatenbylimestone heating and cooling. I got right to their tech department and had the answer within 2 seconds from a guy who had my tank at his house and installed a boiler the size I wanted to.

I put in an IBC boiler last year and played with the parameters to get it right for the house. It took me until we hit the rock bottom of our yearly temperature last year to fully dial in the heating curve.

What problem(s) are you seeing?
 
So I finally got the installer to come out (they were going crazy with no heat calls) and explain to me how the 2107 controller works. I'm sticking with my custom program, but the installer showed me how to adjust the heating curve. He also turned up the boiler temperature a bit which has helped a lot with recovery from setback temperatures. It's performing well with current outdoor temps (30s at night, 40s during the day) but as eatenbylimestone said we might have to revisit it once we see single digits this winter.
 
See, I don't think setback temps work well with a properly sized and adjusted boiler. It takes too long to get back to the desired temp.

The main theories I adjusted to were:

-short cycling is bad, any firing under 6 minutes is considered a short cycle
-ideally, it would run (nearly) continuously on the coldest night of the year, and still hold the temperature of the house.
-in order to get the most condensation and efficiency out of the boiler the return temp has to be below 130. The lower the temp, the more efficiency you can achieve.

Since a given length of emitter is only capable of removing a set amount of heat from the water, you can adjust your max water temperature so that the water coming back to the boiler is 130 or less. The lower your water temperature is, the less heat the emitters will throw off.

Then you look at short cycling. It's bad. It breaks parts. It wastes fuel. Since you can control the heating curve, you can control short cycling to ensure it happens as little as possible. It's easy to find the average temperatures for an area during the winter. Use these figures to help set the temp.

I ended up putting my 2nd zone in with my first zone, and dropping the water temp back to 150 max from the factory setting from 194, if I remember correctly. If I ever hit a temp that my boiler can't hold the temp of the house, I can easily bump water temperature to adjust for the abnormally cold weather. It only takes a minute to change the program.

I just set the thermostat and forget it. An interesting factoid is that the set and forget approach with the low water temp resulted in a house that was really stable in temperature. Winter normally beats my wife, who was raised in Houston. She was comfortable with the new setup.