Hi all,

I have a serious issue with a circa 1999 Peerless gas boiler throwing smoke. All of a sudden it started throwing heavy black smoke. This unit does have a draft fan that is mounted above the furnace exhausts on the side of the house. I do hear that kicking on. As well as the blower seems to be working.

I had the unit serviced last year, but I was not happy with them not actually cleaning the firebox and such, and it seems that for the past three years no adjustments have been required. After the black smoke started I took the liberty of cleaning the unit as required. (figured it was a good start). Of course this did not solve the problem, but at least it is clean, just still smoky.

If I open the fire box inspection port, it spews out a heavy black smoke.

Besides smoking way too much, it does seem to be starting and firing fine. At the moment I have the unit turned off until resolved. A heavy black smoke, I assume an incomplete burn?

Any help would be appreciated. Funds are tight this year and I would like to resolve this myself.

Thanks,
Chris

 

I would advise you get a tech in pronto.

If funds are tight, they will work with you on a payment plan.

To get black smoke from a gas appliance is unusual IMHO...
and for it to just alla sudden start doing this ? shut it off and call a tech.

Oh, check the batteries in your CARBON MONOXIDE detectors too!
You _do_ have CO detectors installed, yes ?

Wait a second.... the title says OIL, but your text says GAS ... which is it ?

My gess is a clogged nozzle and dirty combustion head if it is oil.
You still wanna call a tech for this though.

 

Good timing.

Oh yes 3 carbon detectors in house as I heat with wood (each level) and they are powered with battery backups.

I think before I call, I might try cleaning and inspecting the exhaust fan. Tight on funds and I really need to find someone new to service as I am not entirely happy with the previous service.

I am getting some exhaust (although black), but have to wonder if the draft fan is dirty or not 100% functional.

After that, I will call.

Thanks again.

 

You're getting back pressure from the chamber, which means the boiler is plugged. You need to remove the top and brush & vacuum out the cast iron sections. Be careful of the chamber liner, you can puncture it if you brush too far down in the rear section.

Also, open the door the burner is mounted in and clean from the bottom.

This is a nasty,dirty job, and once it's done you still need to know why it did it.

Main causes:
Lack of combustion air

Poor draft (but probably not with your powerventer)

You can clean out the soot to save $, but still get a simple tune up to set up the burner right.

 

HVACGuy,
Thanks for the response. That was my first thoughts when I took the flue off and started cleaning. It did look like the area inbetween the nipples (for lack of a better term) was clogged, I cleaned and vacuumed it out as best as possible (I am not sure if I got far enough down the nipples), but it was passing through to the fire chamber. Used a plastic brush as I did see the warnings about the soft ceramic.

As far as I could tell there nipples went down about 3 deep. I cleaned good in there and after cleaning the soot did seem to fall through.

The flue part that I did take off seemed to have about 1/8 of an inch of soot on the sides. I think I might take the rest pf the flue off and clean it, and at the same time take down the power venter (thanks for the correct term), and clean that.

Am I correct in assuming that with this much soot build up, there might be a flap or some other element (animal nest even) that is causing the back pressure in the power venter? There is exhaust outside, but still inside as well (even after the furnace cleaning).

After I get it sorted I will definatley call for a tech to tune. I am not happy with the current ones seeing the mess the furnace is in. I have only had this furnace for three years, each year it was serviced, but now I am pretty sure that it was not cleaned as promised. Besides, I am pretty sure I can take my time and clean it better.

FWIW I am in NH and only burn a tank of oil a year (275 gals) as I heat with wood.

Lack of combustion air is not a problem, I hope.... To be honest I have inspected the blower and fan and they seem clean, but cannot find were the air intake for the thing is. It is a Becket burner.

Thanks again for the help.

 

GOT IT!!!!

Thanks for the vote of confidence HVACGUY. I took her apart again today and cleaned her a little better. Got down deeper from the top. There was a big mess down there right above the firebox. Got that cleaned out good and she is a lot better. Used a thin rod to get down best I and got about a 1.5 cups of junk to fall into the firebox. Then from the inside of the firebox as best I could. And yes I did poke the rod through the firebox while cleaning the back as you described. Just a small 1/8 hole maybe.

The nipples on the water jacket sure are a pain to get in between, I am curious as to how the pros do it? Either way she is running fine. I did run her for about 5 minutes, let her cool off and then opened the top and cleaned / vacumened again. So my plan of attack now is :

1. Finish cleaning the flue and power ventor.
2. Let her run for 2 more days and then clean again (more or less she is only hot water).
3. Correctly wire the burner as to allow for it to swing open with firebox door. As of now it is hard wired and the firebox cannot be opened without removing the burner.
4. Replace burner to furnace gasket. See above.
5. monitor CO alarm during process
6. Find new tech to tune furnace within a week.

Anything wrong with this plan?

Thanks again.

 

Sounds like you have the right idea. I have alot of different brushes. For the peerless I use a 3/4" tapered brush and a soot saw if it's clogged. A long piece of flat metal like a slim jim works just as well. Take a flash light and look down through the sections to make sure you can see all the way down.

Did you take the top of the boiler off to get full access?

When you get a tune-up demand a smoke & efficiency test. Lot of techs don't do it unless you ask.

 

I did use a flashlight. Worked great. I also had a lamp pointing into the firebox and looking from the top (yes I did open it). She seems to be doing fine. Local store had the burner gasket and the flue gasket is on order (I feel better getting them replaced.

Also got a recommendation of a new local guy to service the unit. The company I was using was the same that installed the unit before I purchased the home. The fact that you cannot quick disconnect the electrical from the burner to get into the fire box, is enough reason for me to look elsewhere for service. Plus I do not think that it has been cleaned in 10 years, even though they have been doing the service.

Am I correct to assume that a furnace could not of been cleaned for 10 years could still work? And further more would it just go boom one day? That is to say that at some point it is not getting enough draft and boom it starts smoking?

I am thinking there is a fine line to the draft and the point of smoking it does. Or even more so the lack of draft clogs it worse almost instantly.

Either way I am on the right path. Could of been worse even. Plus I saved some money and learned a few things.

Thanks again.

 

I still think yer nozzle clogged up on ya.

 

Are you referring to the filter on the back of the nozzle? Ir the nozzle itself? If it was clogged would it not be spitting out less oil meaning no black smoke? Or could the angle be effected and causing an incomplete burn?

I am pretty sure that this is something that cannot be cleaned. Or can it?

 

Other causes are a broken or warped burner head, malfunctioning fuel pump, burner fan dirty, etc., etc.

 

I wouldn't try cleaning a nozzle...

The actual spray head itself can get teensy bits of crud in them and cause a really poor spray pattern that won't be able to burn properly. Kinda like them flame throwers from WWII... That oil really needs to be atomized to burn right.

Or, what Grady sed too...

Could possibly even be a problem with yer burner coupling, maybe it's stripped out and the pump and blower aren't coming up to speed.

speshully since you sed it started alla sudden...

 

Thanks for the tips.

Nozzle or no nozzle it is beyond what I am comfortable with. I got the bulk of it done (and saved a few bucks) and think it is time to leave it to the expert.

Hopefully it will not be too costly.

Thanks again all.

 

I can certainly appreciate a person who knows when he/she is approaching the level of being in over his/her head. Let us know how things go & if the servicer doesn't perform a combustion analysis, ask him/her to do so & leave a copy of the results with you.