new condensing boiler - different expectations?


Old 12-16-13, 12:12 PM
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new condensing boiler - different expectations?

Last week I had a new condensation gas boiler installed - it was an "upgrade" from my oil burning boiler. The house heats up A LOT slower now, and I'm wondering if this is typical for condensation boilers, or perhaps there's an issue.

I live in a relatively well insulated cape, 1400 sq feet, good dual pane windows. It was about 15 degrees F outside this morning. The new boiler kicked in at 6 AM, the house temperature was 59. It ran continuously, and 40 minutes later the house had reached 63.

I never took numbers, but with the oil boiler it seems the house would have been at 67 or so by that time.

It also seems that the boiler runs and runs for hours to get the house temperature to hit 70. I don't care if takes so long, as long as net energy costs go down, but it would be good to know these differences.

Is this typical? Do condensation boilers run A LOT longer, with less direct heat output?
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Old 12-16-13, 12:38 PM
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First of all, the term is condensing boiler, not condensation boiler. What this means is that the boiler is designed to actually condense the water vapor in the stack gases, wringing out the maximum available heat of combustion. These boilers usually also have a variable firing rate so it is normal for them to burn long cycles.

Now, in your particular case we need to know what brand and model of boiler and how was it installed. Modulating (firing rate) condensing boilers are usually referred to as mod/cons and they have very particular requirements in the installation AND set up of the control systems. If your controls were not properly set up you could have performance far worse than with the old boiler.

Several dozen pictures would help the talented people on this forum evaluate the system. Pictures need to be from a distance so as to see how all the individual parts are connected and also some closer in pictures. They need to be well lit and in focus. Although there is a limited ability to directly link pictures it is best to have the pictures on a photo hosting site such as with the public URL of the album posted here. Do not use tinypic as the forum software does not allow it.
Old 12-16-13, 01:32 PM
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I might also add that it seems you are doing EXTREME setbacks... do you really set the thermostat back so far that the home cools to 59 overnight? You might consider re-thinking that strategy.
Old 12-16-13, 05:28 PM
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If you are using outdoor reset - very common on a modcon, depending upon the heating curve, your boiler output temperature is likely lower than the 180 or more you used to have - that would also account for the longer recovery.

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