furnace initially running rough....

[brewyourown]

Looking for opinions on the following: (a little background as well)

1) oil furnace cleaned in august

2) tech downfired furnace for me from a 0.75 to 0.65 gph nozzle. I requested b/c furnace a bit oversized. Furnace is Carrier 58CMA, 6 years old with Beckett Burner.

3) tech told me furnace was running nicely with new nozzle and he used a test kit for CO, etc....efficiency he told me was 80%

4) tech also told me that the pump was weak and that the transformer was weak. He told me it was not a necessity to purchase these parts and replace, but that at some point in the future, one or both might fail. Said that sometimes a burner could go for years with the weak pump or transformer and sometimes it might go in a month, or it may never go at all...

5) I just turned heat on recently. Not cold enough to make it run all the time, but cold enough to cycle it a few times overnight.

6) Here's what I notice: when furnace kicks on, the barometric damper is flapping back and forth for about a minute or two, then it finally settles down to a somewhat set position tilted inside.

Also, upon initial startup, there is a slight exhaust smell that goes away once it is running smoother. There is also a lingering smell while on, but from previous experience I have tracked this smell down to the new duct tape put on the hole in the flue where the efficiency testing was done, so at the moment not worried about that.

7) The flapping back and forth seems to me to indicate that the fuel stream coming out of the nozzle is not "smooth" right when it starts up, but that over a little time, it rights itself.

Could this be due to the weak pump or transformer? Is this a problem that requires another call to tech? If it is simply the weak pump, I would rather wait until it fails to replace seeing as it seems to correct itself after a minute, but if it is at all dangerous, then I don't want to screw around, I would want to pay for service.

I also thought that maybe there was air in the fuel line, and it needs to be bled?

can anyone give me a hand to help figure out whether I have a major, minor problem or whether I am way offbase with my assumption that the problem is the pump.

[snupytcb]

did he adjust anything or just do his test? how many volts was the transformer putting out? anything below 8000 volts i change. you also need to remember your chimney is not warm all the time when the furnace only runs once in a while, it may take a couple minuts to get warm enough to create a good draft. did he check pump pressure? i am just wondering how thorough the tech was.

[beenthere]

How did he determine the pump was weak?
By pressure test, shut valve test, or vacuum test?

How did he determine that the transformer was weak?
By output voltage test, or spark gap test?

You'll need them to come back and check it. There are many things that can cause this. And it will soot up your furnace and make it less efficient with each on cycle that it does this.

[brewyourown]

did he adjust anything or just do his test? how many volts was the transformer putting out? anything below 8000 volts i change. you also need to remember your chimney is not warm all the time when the furnace only runs once in a while, it may take a couple minuts to get warm enough to create a good draft. did he check pump pressure? i am just wondering how thorough the tech was.

I don't know the answers to your questoins. I believe he made some adjustments, b/c a new type of nozzle was installed.

The chimney thing I didn't think about, but the furnace is really hardly running at all right now, I am just using it to keep the house above 65 degrees at night and it only cyles a couple of times during the night to maintain that depending on actual outdoor temp obviously.

[snupytcb]

as beenthere said i would call them to come back. they should have all readings documented. tell them your situation, most company will be willing to help you.

[brewyourown]

How did he determine the pump was weak?
By pressure test, shut valve test, or vacuum test?

How did he determine that the transformer was weak?
By output voltage test, or spark gap test?

You'll need them to come back and check it. There are many things that can cause this. And it will soot up your furnace and make it less efficient with each on cycle that it does this.


thanks. I just called and made an appointment for them to come take another look at it tomorrow morning.

as far as your questions: i don't know how he determined the pump was weak, but he told me that he measured the low end of accepted voltage for the transformer, but that as long as this voltage is enough to start it that it would be fine, but also that it has the real possiblity of failing and if the transformer didn't put out enough voltage, he told me I would be without heat until it was repaired.

As far as the pump, he said that it was the type of thing that would not cause me suddenly to be without heat, but that the oil stream would not flow through the nozzle like it should which would cause issues.........do these explanations sound plausible?

at any rate, I am taking your advice and they will be back out tomorrow. I really appreciate being able to bounce these topics off of all of you, otherwise I would be home wondering what to do and thinking to myself that I should just live with it.

[snupytcb]

make sure he notes the readings from his test. stack temp, draft at breach and over fire, co, fuel pressure, and fuel cut off pressure. he should put this on your invoice so if he has to come back he has something to go by. just those readings can tell you almost everything you need to know about how your equitment is running and what shape it is in.

[flange]

Another thought......some techs try to hard to get you the most efficiency possible, thikning they are doing right by you. As the weather changes, so do atmospheric conditions, meaning your combustion air density. This can cause problems with misfiring, or even flame failure faults. He may just be trying to hard to do right by you. It sure sounds like some adjustments are needed. If he truly believes you have a weak transformer and pump, he should be selling you new ones to prevent a cold winter night failure. While ignition transformers are pretty durable, they do fail and cause havoc sometimes.

[brewyourown]

Another thought......some techs try to hard to get you the most efficiency possible, thikning they are doing right by you. As the weather changes, so do atmospheric conditions, meaning your combustion air density. This can cause problems with misfiring, or even flame failure faults. He may just be trying to hard to do right by you. It sure sounds like some adjustments are needed. If he truly believes you have a weak transformer and pump, he should be selling you new ones to prevent a cold winter night failure. While ignition transformers are pretty durable, they do fail and cause havoc sometimes.


Is the fuel pump a possible cause for the burner running rough on the initial 1 to 2 minutes of operation?

[beenthere]

It is a possibility.
So is a weak transformer.
Too much air for the smaller nozzle.
The smaller nozzle its self.
And a few other things.

Thats why its important they check it as soon as possible.

[brewyourown]

It is a possibility.
So is a weak transformer.
Too much air for the smaller nozzle.
The smaller nozzle its self.
And a few other things.

Thats why its important they check it as soon as possible.

Turned out to be a faulty nozzle. Tech put in new nozzle and told me he had to readjust things, not sure what that means, but at the end, burner seems to be running great and tech told me it was running great.

Told me that chimney was working very well with good draft. I don't have any measurements, but I trust the guy, seemed like he really knew what he was doing.

He moved the damper knob over toward the higher end, something in the neighborhood of 0.08. It had been set at around 0.05. I asked him about it and he told me the setting is based on what he measures at the burner.

Bottomline, thank you all because I wouldn't have called him otherwise and the tech told me that what I was observing is definitely something I should be calling them about, it meant that it was not operating correctly. And of course there was no charge for the visit given that it was a faulty nozzle.

Does that happen a lot? a faulty nozzle that is.

[Ladiesman271]

Looking for opinions on the following: (a little background as well)


2) tech downfired furnace for me from a 0.75 to 0.65 gph nozzle. I requested b/c furnace a bit oversized. Furnace is Carrier 58CMA, 6 years old with Beckett Burner.





My brother had his nozzle "downsized". It would work for a while and then caused repeat problems. After three trips to repair same (on service contract), the original size nozzle was put back in. That cured the maintenance headache!

[snupytcb]

My brother had his nozzle "downsized". It would work for a while and then caused repeat problems. After three trips to repair same (on service contract), the original size nozzle was put back in. That cured the maintenance headache!

it seems some units just don't want to run when they are downfired. the old peerless pin type boilers were always a struggle for me. if i downfire i just bump the pressure up and adjust accordingly.

[brewyourown]

still curious.....the barometric damper is set toward the high end now, something like 0.08 and when the burner was running, it doesn't open at all.

Tech told me that was OK and that during winter I may see that it does open up some, but that it is OK not to be open.

Is that correct?

[beenthere]

Not unusal to have a nozzle go out relatively soon after install. But, is sometimes a sign that a short cut was taken when the cleaning was done.

Depends what his over fire draft reading was.

Do you know what it was.

[brewyourown]

Not unusal to have a nozzle go out relatively soon after install. But, is sometimes a sign that a short cut was taken when the cleaning was done.

Depends what his over fire draft reading was.

Do you know what it was.

I don't know what it was unfortunately. He told me that I had a "good" draft and also that he could tell that my chimney was working very well.

Anything to offer regarding my question listed just previous to your post regarding whether it is OK to have the barometric damper not open much if at all during burn?

[beenthere]

During milder outdoor temps, its not uncommon for the damper not to be open, or not open very far.

Again, this depends on what the over fire draft is.
That damper is used to maintain the same over fire draft at various outdoor air temps. That effect the amount of draft the chimney has.

[brewyourown]

During milder outdoor temps, its not uncommon for the damper not to be open, or not open very far.

Again, this depends on what the over fire draft is.
That damper is used to maintain the same over fire draft at various outdoor air temps. That effect the amount of draft the chimney has.

OK, that kind of jives with what he told me. He said that when it got colder, I would likely see the damper open up a bit.

At any rate, furnace seems to be running great, It had always previously been set so that the damper was open when running, this is first time that it is running with the screw knob set so far to right and not open.

I need to just slowly walk away from the furnace, slowly...lol

[snupytcb]

I don't know what it was unfortunately. He told me that I had a "good" draft and also that he could tell that my chimney was working very well.

Anything to offer regarding my question listed just previous to your post regarding whether it is OK to have the barometric damper not open much if at all during burn?

the damper will open as needed, if it is set corectly. he told you the chimney was fine but did he tell you how clean the hx was?

[brewyourown]

the damper will open as needed, if it is set corectly. he told you the chimney was fine but did he tell you how clean the hx was?

no, he didn't say anything about heat exchanger. He was just here about a month ago for an annual service/cleaning. So I assume if the heat exchanger was a problem, he would have said something?

[beenthere]

I worked for oil companies for over 12 years.

I was never told to make a burner use more oil.

How ever, I was told it wasn't my job to make it work too efficient, after all, we made our money by selling oil. :(