Boiler Banging

Jason_4

The boiler is a Crane sunnyside 102A from 1974 or 1975. I moved into this house about 4 years ago and the boiler has worked fine. I've done little to it except put a new motor on it and had the main burners cleaned. I don't know much about this so please excuse the poor terminology. I don't have zones, once the thermostat kicks in all pipes get hot. The problem i'm having is when the thermostat kicks in and tells the boiler to go, it does but it after about 5 minutes it makes fairly loud knocking or hammering sounds from what sounds like the inside of the boiler. It wakes us up at night. This noise will last for about 5-10 minutes and slowly go away the hotter the boiler gets. What is causing this and what can i do about it? I'm fairly handy so i'm not afraid to open her up. I tried cleaning the main burners as there was a lot of white soot build up, this seemed to help some but the noise came back again. These noises occur everytime the boiler is turned on. Please help

leroy

Boiler banging

Is this a steam boiler ,hot water,gas,oil,what?

ScottMP

Jason

Tell us more about your boiler. Is it forced hot water ? Do you have radiators or baseboard ?

If it is forced hot water, it sounds as if you have mineral deposits built up inside your boiler. There has been alot of discussion about that here on the wall. Some believe that by using cleaners you can reduce the build up. I do not. I believe your boiler will ned to be replaced to eliminate this problem.

Again this is only a guess from what you have said. Tell us more and maybe some one can help. There are others reasons for knocking, but we need some more info.

Scott

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Jason_4

I have baseboard heat. Natural gas. Not sure what "forced" hot water is but the system has a motor attached to the boiler that turns on when the thermostat kicks in. The water is moving. Does this help? The banging noise starts out loud with at infrequent intervals, then slowly it gets quiter with more frequent intervals and all of a sudden it stops banging and the boiler continues on with no problems. Like I said, the noise starts about 5 minutes after the thermostat kicks in, lasts for about 5 minutes, than nothing.

[Deleted User]

I found

the Series 02 Sunnyday in the boiler rating book. The 1 does not compute. Sounds like the boiler stays hot all the time. Am I correct? Do you heat domestic water with it?

Next question. When the motor (that is the circulating pump that moves the water thru the baseboard) is off, what is the temperature and pressure reading on the boiler gage? Don't pay any attention to the red hand. Just temperature and pressure. Please write them down.

Now. While you are looking at the gage, have someone turn the thermostat up. Keep looking at the gage, when the pump comes on, write down what happens on the gage, and the sequence in which it happens. Then jump back on The Wall & tell us. Bet someone here can help w/ your problem.

Good luck.

Jason_4

I heat water that comes from the same water that I drink (city water). I can add water to the system as needed. Normally I don't need to add anything at all.

The water is not always hot. With the thermostat off for about 1 hour, the water in the lines are around room temp and the temp gage is pinned below 100 degrees. The pressure gage stays around 13-15 psi with the boiler not operating. When the thermostat kicks in, it takes about 5 minutes and the temp gage will start to move (the first line is 100 degrees), the pressure will go up a little but no more than 20 psi. The boiler will shut off when water temp reaches about 240 degrees (i may be off a little) and will fire back up once it cools down to around 175 degrees or until the thermostat tells it to shut off. Hope this helps. The noise starts once the water temp is around 115 degrees and ends around 140 degrees. Pressure stays the same.

[Deleted User]

You aren't drinking

the same water you heat with. If the boiler is heating the water, it is doing it thru a heat exchanger where the 2 waters never mingle.

The 240 degree number is interesting. At temperatures over 200 degrees w/ any air in the system, it is possible to generate steam. Not good. Circulators and hot water systems don't like steam. Can cause problems besides the noise you are hearing.

If you can find the boiler temperature controller, see what it is set at. For a boiler that heats hot water & baseboard, settings should be around 160 for the low limit & 190 for the high limit. Give or take 10 degrees.

Try that. If the problem continues, call a professional to eyeball it.

Happy hydronicing.

Jason_4

My bad, the gage goes up to 240, the high temp limit is about 200 degrees. To clear things up, I didn't mean I drink the same water as what runs the pipes, what I meant is I have a valve that I use to fill the pipes if needed, this is the same water as what is used to drink from.

So after all this info, any suggestions on my problem at hand? Would it be helpful if I posted pics of my boiler setup?

joe_6

Yes

pictures speak a thousand words.If you are not using the boiler to heat your domestic water(drinking water )i would lower the hi- limit setting on your boiler to 180 degrees.Sounds like you could have air problem or like somebody said deposit buildup inside boiler.Hard to tell without seeing how the near boiler piping is piped.Is circulator pumping away from boiler or into boiler?Where is compression tank connected to system,on suction side of pump?or to boiler?

Eric

Pressures

What is your pressure relief valve set to on your boiler?


How many stories is you home? feet of pipe above your boiler?

Jason_4

1 story plus basement. All hot water pipe is above boiler. Pressure valve is 30 psi. Living plus bed rooms is 1100 sq feet, how much pipe that equals i don't know.

Here are some photos, you guys/gals are asking questions I have no idea to what the answers are. I've always wondered which way the flow is but I don't know. The upper limit is 200 degrees and the gas will turn back on around 185 degrees. All the attachments for the boiler are in the two photos, everything else not shown is baseboards and copper pipe. Like I said before, these noises just started this winter, i've never heard them before. Is damage occuring or will it just always be noisy?

ScottMP

All of the questions

Above are good ones.

After seeing the picturs and answers, I'll go back to what I said before.

Deposits in the boiler, and the boiler is heating the water trapped in the deposits. As this water gets super heated it "explodes" out of the deposits and this is the banging noise you here. Not the most technical explanation but I've seen this before. You can try adding a cleaner to the system and then flushing and refilling after a week. This somtimes helps.

Look for a new system this summer.

Sorry, just my opinion.

Scott

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