steam boiler

[heatseeker]

Weil McClain boiler 68 series, costumer let fuel oil tank run to empty. went to check it out bled air from fuel line,changed nozzle & filter. Fired it up it worked fine,boss always wants to run several cycles on everything we work on to make sure everything is working right. Evetything tested good,done smoke test,draft test etc.


Let boiler run for awhile while i was at lunch. Came back and the pressure relief valve had released some water onto the floor. had to replace the relief valve , fire the boiler again and got a puff of smoke when it fired.

The rest of the day the thing would fire perfect and then the next time it would smoke again.Fire good , smoke,smoke,fire good. ???

[tinker toys]

Do a pump pressure test. sounds like your dripping fuel out the nozzle during shut down

[heatseeker]

done a pump pressure test,showed 120 psi & a vacuum test, still the darn thing will fire perfect one time and puff smoke the next

[condenseddave]

The relief valve has nothing to do with the smoke problem. That 15 psi relief popping should worry you. What is the steam pressure????????

What was the vacuum cutoff and is this one or two pipe?

Draft? Chimney, power or direct vent?

Pump strainer?

Actual combustion test results?

Cad cell resistance?

Need a lot more info.

[condenseddave]

Weil McLain 68?? Does this have their old QB burner on it?

[heatseeker]

The smoke test showed about a 1,& the draft test showed 6.It is direct vent into a chimney,the steam presure is 18 but keeps trying to rise to around 20 psi,the pressure relief valve is rated 30 psi. The boiler runs fine but you still get that puff of smoke about every third fire up.

[heatseeker]

did not test the cad cell,but did't thing it would be the problem since this thing fires perfect sometimes and it runs good even after it fires with the smoke puff, Dave

[nutshell]

Draft should be closer to -.03. Also 18PSI in a steam boiler...that is a bomb waiting to go off. Steam should run at half a pound.

[condenseddave]

Originally posted by heatseeker
The smoke test showed about a 1,& the draft test showed 6.It is direct vent into a chimney,the steam presure is 18 but keeps trying to rise to around 20 psi,the pressure relief valve is rated 30 psi. The boiler runs fine but you still get that puff of smoke about every third fire up.

First off, if this is a residential steam boiler, in a typical home, that pressure is dangerous. The relief on a residential steam boiler shouldn't exceed 15 psi. That 30 psi relief has turned that boiler into a bomb.

The steam pressure should be no higher than 2 psi.

The presssures you list are typical of hot water boiler pressures, and would be normal for hot water.
Are you CERTAIN that this is steam????

[condenseddave]

If that is steam, and it's residential, either call your boss or the homeowner, and get them to turn that off NOW.

Seriously. That needs IMMEDIATE attention.

Smoke is the least of your worries right now.....

[condenseddave]

Heatseeker, you out there??????????/

[heatseeker]

I'm back Dave need help, the draft pressure i quoted may have been wrong the company i work for has very primitive equipment, so that draft reading may have been wrong, this draft gauge is old and doesn't work right some time, Stupid question. When the needle drops to the right is this a negative or a positive reading?

[heatseeker]

The burner on this thing is called Blue Angel,this thing was installed in 1988