HX "Coffee Grounds"

ced48

In searching for old references to the debris found in modcon heat exchanges/condensate traps, I found no explanation as to what they were, or what caused them. I still don't know what they are, but my new guy at Lochinvar assured me that they were the result of poor combustion. So, they are not a good thing, and even if you are adjusted to factory combustion parameters, as in my case, you still might not be getting good combustion. We are still working on getting better combustion, and quiet operation on my WH 55. I will update as things progress.

Don_197

Do you have pictures? Did the coffee grounds collect on the inside (fire side......where the burner sticks in to the Giaonanni heat exchanger) or did they get flushed out of the water side? (btw is this the firetube wall hung or the water tube?)

ced48

No pictures, WH55, debris was in the condensate trap, and most likely on the floor of the HX, I haven't cleaned it yet, as we might be replacing the gas valve, will do then-

SWEI

You just found one of the real benefits of downdraft vertical firetube heat exchangers: The condensate continuously washes the HX as it moves towards the drain. Clean the drain regularly and you probably don't have to worry much about cleaning the HX. Contrast this with a horizontal spiral watertube HX, where the kibbles & bits end up sitting on the coils.

ced48

Yes, I was thinking that-I stuck a rubber tube up the drain, moved it around, and nothing came down. Must be washing itself clean.

Tom_133

The few times I have had "coffee grounds" in the Hx was coming from particles in the intake air. One job was at a wood shop, it had all the vacuums and filters in place around the shop but the dust was unstoppable and no matter what the boiler cover is never 100% air tight. It was sucking in a bit of wood dust all the time. I mentioned to the shop foreman and he spent a day sealing the boiler room from the rest of the shop. That has made a huge difference. Instead of every 6 months needing to clean burner (gianonni) now its every two years. Also found it on a boiler where the intake is 100+ yds from a corn field and in the fall it seems that when in that field harvesting it causes huge corn dust. Boiler sucks it in and bam no start. These are just my take on it, it could also be a bad mix but both were set to manufacturers spec and after cleaning and tested were still right there. I like the fire tube Hx for this reason as well.