water in flue

Jim Davis

Your oil boiler is condensing! Temperature and draft need to be measured, including the draft after the boiler shuts down. Negative pressure in the room may allow draft during the run cycle, but as soon as the boiler shuts down the draft may cease and the gases will be trapped in the chimney to cool. By the way, 100psi only works good on oil if you heat your oil to 80 degrees(factory test).

Bill_18

water in flue

We have a customer with an exterior masonary chiminey, two story house. Steel boiler 120,ooo BTU. There is a lot of water present in the base of chiminey, it actually runs into the boiler. A chiminey cap has been on,but it really hasn't been rainy anyway. It has however been cold here on Long Island. Could it be condensation? Thanks Bill

Chris V

chimney

What's the temperature going up the chimney?

scrook_2

questions...

Could be condensation.

Gas or oil? Original fuel or conversion?

Hot water or steam? Is it using/using excessive water (e.g. small leak to fireside)?

120,000 the boiler input (output?) rating or the actual/nominal firing rate?

If oil what's the nozzle size and what's the oil pressure

If gas, does the gas flow when the meter's clocked agree w/ rating & what's the gas pressure?

What's the stack temp *before* the draft hood or regulator? What's it after the *hood* or regulator?

What's the chimney lining, tile, metal, none, other?

Bill_18

Re Questions

Its an original (5 yrs old) oil fired steel boiler firing .85 gals with a pump preasure of 100psi. Its your everyday brick exterior chiminey with clay lining. I didn't take stack temps. I can see how that would be a factor. Gas boilers condense I know, but never seen it with oil. Boiler doesn't seem to be leaking.

S Davis

What size is the flue off the boiler and the clay liner?
If the clay liner is too large the boiler will not be able to heat it past condencing temp. especially on an exterior chimney. The boiler manufacturer should have flue size charts.

S Davis