Oil Burner Deposits

Jim Davis_3

Sounds like it is underfired. White residue is usually condensation that never gets out because of low temperatures and poor venting.

Kyle_5

Looking inside the burn chamber of a boiler recently I noticed the entire heat exchanger is coated with a white deposit. Can anyone tell me, with as much detail as possible, what is causing this? Obviously the burner is not calibrated properly, but what exactly is behind this? Not enough air, too much fuel, contamination, additives? The oil tank is outside, the boiler is a 1994 Peerless.

Thanks for your help.

Steamhead (in transit)

Can also be caused

by too much air mixed with the oil during combustion. This should only be checked and readjusted with a digital combustion analyzer. If this is a hot-water boiler, it may be getting too much cold return water. A bypass or primary-secondary setup is the cure or that.

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Steve Eayrs_2

Or how about......

operating the boiler at too low of a temp???

Could be your running this thing lower than what you should. Would account for low return temps, as well as supply. What is the operating temp of the boiler?

Steve

herb_4

any one think of the environment the boiler lives in that also has a big impact on deposits such as this.

bill_97

Yes it does

Good point Herb . If the oil burner is picking up air heavy in cigarette smoke or dust , it'll leave a whitish deposit in the chamber . We see this often in homes with the boiler in the kitchen .

Jim Davis_3

Other than combustion air the environment never causes problems with deposits or corrosion or rust etc. If they were from dust it could only happen in the off-cycle(this would burn off) and cigarette smoke is yellow.

Don't know how you could have low return water if you are in the heating mode. Any water temperature above 100 degrees is not low.

Low temperature burner operation from underfiring which can create too much excess air is the only real problem. These in turn create poor venting.

Paul Fredricks_6

Plenty of installations have problems with condensation due to low return temps and a cold boiler. Why can't that be the situation here?

Jim Davis_3

Low return water temperatures has long been blamed for condensation problems versus burner operation. An oil fire burns in the upper 3000 degree range and possibly in excess of 4000 degrees. Whether the water in the boiler is 40 degrees or 160 degrees it is not going to change the flame temperature enough to cause condensation for more than a few seconds. A cold flame(too much excess air) and poor venting cause condensation no matter what the water temperature.

Never could understand why on large boilers they always used low-fire hold when they are cold. Condensate dumps out of them during this time. The same boiler adjusted to fire in high-fire on start has hardly a drip. The weird part is that on fire-tube boilers the need for re-tubing or puncing tubes was reduced substantionally.

Remember, standard water heaters fire at high fire all the time when they are bring in 100% 45 degree street water. If they didn't we would have water all over our basements.

Paul Fredricks_6

Makes sense to me.

herb_4

in my opinion yes the environment has a lot to do with both combustionand depsosits and such. I gguess the customers equipment i service in my area are much different then anywhere else. I have seen boilers that live in nice low humidity warm wel taken care of basements thatlook like brand new when i go to clean them to boilers that look like someone dumped a gllon of rusty water on them that live in some of the nasty environments.

Toddid Goldsmith's

White deposits

If the environment air in which a cold start boiler, that supplies boiler water to an indirect hot water heater has a temp. of 80 degrees f., and a relative of 95% comes in contact with the metal surface of the boiler which is cooler than 80 degrees f. condensation will form on the metal surface, and it will rust.