My Burnham Alpine Condensing High Efficiency Direct Vent Gas Fired Hot Water Boiler is Possessed

KProuty

HomeJ

HomerJSmith said:

Looking at your exhaust and air intake, I would have done it differently. I am concerned about gas reversion and never use concentric venting and when I use a two pipe system like yours, I always put the exhaust vent 18" higher than the air intake vent with a 45 deg take off on the exhaust vent raising it 18".

This may sound crazy, but I'm half crazy anyway and working on the other half. So, let me ask you about the water quality in your boiler. You have an aluminum HX and the manufacturer's requirements as to water quality must be conformed with and checked on a yearly basis. Was your boiler filled with tap water and is that water mineralized to any degree? Is there any chance that the inside of the HX has a carbonate build up and that is causing your groaning? Sounds like expansion in the HX. Other than that, I would look at combustion and have it analyzed. Hopefully, it was done at commissioning.

Maybe call an exorcist? hmmmm.

Homer, were you talking to me or Jasper with the above questions. If me, I have no idea about our tap water, but we don't have to treat it with anything and it seems to be fine. The combustion seemed to be the problem, but Jasper is right, it does groan for like a second before the new mix turns on and then it stops groaning immediately.

HomerJSmith

I'm still concerned about the quality of the water. I'm a big believer in DI water in a system. The hotter it is the more mineralization comes out of solution and solidifies on hot surfaces. The hottest surface is the wall of the heat exchanger.
It doesn't take much of a mineral build up to interfere with the transfer of BTU's from the HX to the water within it. The heat energy instead of being transferred to the water remains in the HX. Flue temperatures also rise. My thinking was, if that is the case, the HX might be groaning because of the expansion brought on by the retention of excessive heat in the HX. Once that expansion stabilizes the groaning stops.

The duration of the groaning and the temperature of the boiler during it's occurrence and the timing of the groan in relation to the combustion cycle and your ability to discern its location should give you a lead to its cause. Use a mechanic's stethoscope on different places in the boiler and try to locate the source of the noise.

I was talking to Santa Clause because he obviously had the same concerns about the venting as me. Venting is a big deal with Mod/Con boilers. When Mod/Cons became a rage, gas reversion destroyed a lot of boilers and that was the direct result of bad venting.

Do your combustion analysis with an analyzer and set the boiler to the manufacturer specs and that includes input gas pressure and draw down of the gas valve if your boiler pulls a negative pressure on the gas valve.

I don't much cotton to the idea or turning down a screw on the gas valve and listening for the result, that's really old school.
I want an analyzer that tells me the results.

JeffGuy

Hey KProuty, in case you still check in here. It sounds like I may live close to you. I thought I had a good plumber who knew Alpines, but he proved me wrong and was unable to give me a worthwhile combustion test. Could you let me know who you used?