Vitodens checkup (SE)

Steve Ebels

It was raining condensate. Literaly. And it makes sense because Jim McCarthy from Viesmann told me that the flue gases pass between the heat exchanger gaps at around 45MPH if I remember correctly. That kind of velocity would probably serve to trap all the moisture and send it down the drain instead of out the pipe.

Steve Ebels

I drove up

To Boyne City yesterday (what a beautiful spot to live) to check on a Vitodens we had installed on a staple up job. The HO indicated they hadn't been there since Thanksgiving day weekend and we had just fired it up the last of Sept. I arrived about an hour early and while waiting for the local guy to arrive with the key I was watching the vent pipe for signs the boiler was running. I saw no steam or any sign of life at all. The vent exits the house about 10' from ground level so I couldn't reach it to check for heat. Walked around the house to look at the gas meter and found it covered up with construction material. Couldn't see it to observe if any gas was being used. Being paranoid by nature my mind is now telling me that the boiler has quit and the place is completely frozen solid. We had mornings last week of -18 and -11. COLD!!

The key guy finally came and to my relief, a nice warm home greeted me upon opening the door. So now my curiosity is aroused. I hadn't seen any sign of life from the boiler in over an hour and I couldn't imagine that it hadn't cycled in that time. Upon inspecting the boiler I found that it had been cycling the whole time. The water temp was 88*. Indoor temp was 62*. Floor was running in the low 70* range. The burner was on, the pump was running, heat was being moved and all those normal things a boiler does were happening. When I raised the indoor setpoint I could faintly hear the boiler as it throttled up to a higher firing rate. The water temp kicked up to an average of 96* and the burner went down to an idle again as it maintained that level. At this point I went outside and looked at the exhaust again. Still not a trace of vapor.

So what gives here? Why no exhaust vapor? Atmospheric conditions? (ambient air was 33-34* and humidity was high) Does this thing operate at or very near 100% eff. at these water temps. Supply around 90 return around 72-75* ?

One of you really smart guys must know the answer to this?

Chris Maderia

Vitodens

It's base AFUE is 94.2%. The Modulating Matrix gas burner has extremely low emmissions, NOx: 8.9ppm/ CO: 5.5ppm.

Dale

What was the drain doing?

At 34 degrees you may not see much water vapor outside. You should see the majority of the water that's in the gas going to the drain. Remember the byproducts of gas combustion are CO2 and water vapor with the nitrogen going along for the ride.

steve gates

the one we set

is doing very similar. Our first one. NOT my last. The exhaust is so lazy I tought my kid had tought it something it should'nt know. I wonder if the intake is getting some of that exhuast?