First cleaning in 4 years

Solid_Fuel_Man

This is a W-M eco70. Installed fall of 2017. Looks pretty good, does this look a little dark to you? Ringed with hot water, and "scrubbed" with cotton rag. Very little coffee grounds in this one, the after picture shows a slight staining of what looks like coffee grounds, but are just black dots. 

Serviced the trap, neutralizer, and rinsed the exhaust. 

delta T

for 4 years untouched looks pretty good i'd say. Can't argue with those combustion numbers!