Hot water oil burner shuts down with a "wa-thump"


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Old 01-06-03, 09:50 AM
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Hot water oil burner shuts down with a "wa-thump"

I have a thirty or so years old oil burner hot water furnace. The furnace is making a loud "wa-thump" noise when shutting down. We are relatively new to the house and I'm not sure but it does seem somewhat louder than a month ago. Otherwise, provides good heat, and also is the domestic water heater as well. Typically only needs to run about 5-10 minutes at a time. Does the noise signify some problem? If so, can you surmise what needs to be done?

Thanks.
 
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Old 01-06-03, 10:20 AM
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oil burner

When was the last time you had someone look at and work on the burner??Im sorry but after 40 years as a hvac this is the first time I have heard of a burner that on shut down went WA-THUMP
Need more info here, is it the oil lines , burner , boiler, water lines? ED
 
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Old 01-06-03, 10:31 AM
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The noise happens inside the furnace, either the burner or the boiler I guess. Another way to describe the wa-thump would be a moderate "bang" and "bump". It is hard to describe a noise. I'll try and do a real good listen when I get home tonite. Thanks.

The furnace was checked out by the previous owner in May 2002 who provided a receipt showing some minor adjustment (?) and costing about $185.
 
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Old 01-06-03, 02:00 PM
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dave houlihan:

Hey, the oil burner in a house I use to own did that.

Cleaned the chamber and burner, installed the correct nozzle, adjusted the spark gap and it still did it. After a while we never heard it any more.

It was the equivalent of the little pop you sometimes hear when a standard gas burner shuts down.

Someone will likely be along with a GOOD explanation.
 
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Old 01-06-03, 02:20 PM
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Thanks GregH, I was just wondering what you meant by "we never heard it anymore" - does that mean, it was still there and you just stopped noticing, or, it really went away?

Thanks!
 
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Old 01-06-03, 04:36 PM
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Sorry about the lack of clarity.

I meant that it still did it but we got used to it.

I asked a local oil burmer tech about it and he said don't worry about it................so I didn't.
The reason I didn't worry about it was we were planning to switch to electric heat.

In your case I would search out a permanent solution.
 
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Old 01-06-03, 07:10 PM
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Sounds like the Weil Mclain Wa-thump to me.
 
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Old 01-08-03, 04:26 AM
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The Weil McClain wa-thump

Ok KField - The Weil McClain wa thump. Sounds like you mean the domestic water heater thing a majig which is somewhere inside this boiler. I don't know if it is a Weil McClain in there or not. The nameplate on the outside calls my boiler "The New Yorker" which I think is made by York.

So do you think my wa-thump is typical of this Weil McClain. Can you explain a little further please. It would be much appreciated. Thanks.
 
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Old 01-08-03, 05:31 AM
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Actually, the Weil Mclain reference was based on the number of complaints I get from people who say their boiler lights with a thump and is loud in general. If yours is a New Yorker, it is now owned by Burnham. It is not a bad boiler but if you have the FR model you cannot successfully reduce the firing rate below the manufacturers specs. without problems. There is no refractory combustion chamber and the burner is on its own for clean combustion. If you want to dig into it, reply with the boiler model and max fire rate from the name plate. and I'll give you my 2 cents on setup. You will still need someone with a combustion test kit to do the fine tuning.

If it is around 10 years old, look on the burner for a sticker that says it has an air inlet damper installed. You will probably awant to get rid of that thing if it is still in there.
 
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Old 01-08-03, 12:01 PM
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Thanks KField. I wish Easton were a little closer to Binghamton, where I am. Heres the info on the New Yorker, the model is FR 147, and per my wife the firing rate is 1 25 804 which is what she read to me over the phone, hope its right. And 147,000 btu's.

It is a loud burner when on. It does kick out the heat and hot water. It almost seems to big for our heating needs cause it only runs for about 5-10 minutes at a time. As for the hot water, it is tooooo hot.....like the coffee you could sue McDonads for. And there is apparently no way to adjust it.

Any advice you have is appreciated. As mentioned in my earlier post, it was probably tuned in May 2002 by the previous owner. So if the noise I am hearing is somewhat normal, I don't want to have a service call.

Thanks.
 
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Old 01-08-03, 12:39 PM
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The noise is probably not serious at all and may be difficult to stop unless it is the draft regulator. When you are near the boiler and it shuts off, can you pinpoint the location of the sound. Inside, outside, front or back. The 1.25 is the correct nozzle for that unit and should be 80 degree Hollow pattern. So the 804 that your wife read to you should be 80 A or 80 H both being hollow. If someone used a Solid pattern nozzle, you could get a slightly noisier fire, but not by much. As long as you keep an eye on the hot water coil gasket area for leakage, that boiler will last a very long time.
 
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Old 01-16-03, 04:49 AM
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KField - I've had a hard time determining where the noise comes from, its seems either from inside the middle or towards the back (the back being where the exhaust vent is), but I can more accurately describe the noise as a shudder, or vibration.

But another problem has arisen. For the domestic hot water, I seem to be losing pressure somewhere within the boiler, or coil, or whatever is in there. I believe this is so as I have spiggots on the inlet and outlet sides, on the inlet side the pressure is normal, on the outlet side the flow is reduced by half or more.

I have drained about 5 gallons each from both sides and no change and no notable amount of debris coming out. I assume there is still some type of blockage in the coil. I am contemplating backflushing the coil by attaching a hose on the outlet side and openning the spiggot on the inlet side (I have enough valves in my water system to isolate the boiler/coil).

Is this a feasible approach and/or what else can I do to investigate or correct the low pressure problem. This is a New Yorker FR 147 as I mentioned a few posts back.

It would also help me to be able to conceptualize what the configuration is inside this boiler. I can see the heat lines and domestic hot water lines going in and out, but the guts are a mystery to me. Is there a tank for each, or coils or what?

Any input on these matters is greatly appreciated. Thanks!
 
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Old 01-16-03, 06:02 AM
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On the domestic hot water side, it sounds like a mineral build-up problem inside the coil. Do you have a well? If so do you have a water softener or hard water?

To picture the way the boiler heats your domestic water. Look at the plate that the hot water coil fittings are on. Behind it is a coil of finned copper tube that looks kind of like a slinky. Probably 20 feet of small diameter copper tube that reaches back into the boiler and is immersed in the boiler water. It is a continuous piece of copper from one fitting to the other. The reason you may have all the fittings on your hot water coil could be because it has needed an acid flush in the past. It is necessary to have all those valves to run acid through the coil and remove the calcium.

The rest of the boiler is one big water container.

As an experiment you might try just cracking the sight door on the front of the boiler open like 1/8" and see if the noise stops. Or even if it changes. If it does, it is a combustion related noise and you can track it as such.
 
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Old 01-16-03, 07:04 AM
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Thanks again KField.

I do have a 160' deep well and presumably hard water. There is an old water softener before the coil which is currently bypassed. The previous owner of this house I have been in for 6 months implied it did not work per his disclosure form and I have not touched it. I assume there are deposits, though the drop in pressure seems to have come on abruptly, not gradual like you would expect.

As for deposits in the coil, you mention an acid bath. Should I get a pro? Could I try something like CLR and do it myself?What would you recommend?

As for the noisy boiler -- I'm a novice -- by the sight door, do you mean the approx 20" x 24" heavy metal plate with a handle on the front? And crack it open during firing and shut down?

Thanks again.
 
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Old 01-16-03, 10:38 AM
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hot water

You said that you had valves there and you could lock off the hot water coil in the boiler from the home. If you can do this This is how we clean out water coils. Get a bucket fill with the CLR , acid or like calgon , Nu-coil.
Now with a short hose from the out water of the coil put it in the bucket. Now get one of those cheap little pumps that go on a small electric drill.On this pump put a short hose from the bucket and a short hose to the in let to the boiler coil and turn on the drill. You may have to renew what you use in the bucket from time to time as it will lose its power to clean.You see you are takeing the water out of the bucket through the coil and back into the bucket. When you are done be sure and flush the coil out real good before you turn it back on in the home. I would also look into that softener and see if the bypass is ok and if your water is as hard as you say get it working also. ED

Yes KField meant That big door if thats what you have just a crack like he said
 
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Old 01-16-03, 11:16 AM
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The door I wanted you to crack open is below the clean-out cover you described. It is just above the burner tube and is only about 5 " wide by 4" high.

Good luck with the acid. It is relatively dangerous but the only way to get the job done. I use an SOS produce called lime-solv but there are probably many names for it.
 
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Old 01-17-03, 09:57 AM
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Thanks Ed I and KField -- I will try the coil flush this weekend and let you know how it turns out.
 
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Old 01-20-03, 09:58 AM
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The coil flush worked great!!!

I had to look at the local plumbing supply house,Lowe's, Home Depot, Wal-Mart and then finally found the little pump that fits on an electric drill at Sears Hardware for about $6.50. I picked up a bottle, about a quart, of Lime-Away for $3.50 at Home Depot (only $3.00 at Wal-Mart I later discovered). At the plumbing supply house they told me only their acid would work, but the warnings were so ominous I preferred to try something less powerful.

I circulated on and off for about one hour and then flushed it well.
There was dark reddish sediment in the sink that I flushed into. Would this be iron? Or what? Anyways, the pressure is back to normal.

I am very pleased and grateful for the advice from Ed I and KField. It looks like I need to do this two or three times per year. I see from the recepit the last time this was done by the previous owner it was $100!!! So I am going to save a lot of money.

Next, I'll get back to the noisy shut down.

Thanks again -- this is the best site on the entire internet!
 
 

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