Where's the air coming from?

richard_14

short cycling sounds like the puff back control is being accuated, blocked chimney or heat exchanger. check draft over fire. also check the main circulator for operation. do you have heat in all zones? ....rich

Steven Murray

Where's the air coming from?

I've got an Energy Kinetics EK2 oil-fired, hot water baseboard system (also providing domestic hot water). A few months ago the thing started short-cycling; it would fire for 10-15 seconds, shut off for 10-15 seconds, rinse, lather, repeat. Seems air is getting into the system from somewhere. Flush it, and things are good for a day or two. Then, the air's back. There are no signs of leaks anywhere. Bleeder valves are spitting water, not air. Now, to add to the annoyance, there's banging from what I assume is hammering due to the trapped air.

Where could the air be coming from?
Why doesn't the air rise out of the boiler to a point in the system where a bleeder valve could be used to release it?
Why doesn't the air escape out the vent cap?

TIA.

Brad White_9

Basic Questions

1. Is the circulator pumping AWAY from the expansion tank? (It should be.)

2. Conversely, is the expansion tank on the discharge side of the circulator, say on the boiler outlet with the circulator at the boiler inlet? (It should NOT be.)

I am surmising that you are pumping TOWARD your expansion tank. This has the net result of drawing a negative (sub atmospheric) pressure on the suction side of the circulator.

I saw one just yesterday which had a vent on the suction side of the cicrulator. When the pump ran it sucked in air. (It acts as both an air-out kind of vent and an air-in vacuum breaker by the way.)

My $0.02

Brad

clammy

leaks

Is your home of slab construction?If so do yourself a favor and check your boiler s water pressure then shut off your feed water to your boiler wait and see if the water pressure drops and by the way have it running also.The reason i say this is many years ago and still now guys used to save alot of time and drilling by roughing copper in the slab for 1 st floor heat but over time some times the copper cracks and developes small leaks so you boiler loses water but wait thatr pressure reducing valve is always keep water pressure in the boiler so what happens is you end up with air promblems on the second floor .You see the water leaking into the slab and all the air that's in the water ends up in the highest loop .Do a little investigating and you may be surprised at what you find.If it seems like alttle more then you cabn handle you can use the find a pro listing avaible on this site and find a professinal who will find and fix what ever ills your heating system peace and good luck clammy

Steven Murray

no slab

Thanks for the idea, but the house is not slab construction. It's a 150 year old Federal; none of the pipes are buried in concrete/cement.

I wish the air were in the highest loop. At least then I could bleed it out. For some reason though, it's getting trapped in the boiler.

Elmichael

air in system

Check your gauges on boiler.I've seen where they fill up with liquid or air is sucked in. It never ceases to amaze me on how cheap they can make a guage now a days

Nick L. in Vt

air

how old is ek-2, seen them leveled out and not able to eliminate air. energy kinetics=level the base not the boiler

Leo

Did someone

Has someone changed any settings? Your description sounds like overheating and flashing to steam. I saw one once where a tech changed an aquastat setting during an annual tune up and it did what you are describing.

Leo

Steven Murray

Got heat

Actually, the puff back control was disabled years ago. Long story.

Main circulator is working.

I have heat in all zones (except for 3rd floor, which is shut off).

Steven Murray

age

EK2 was installed in 1998 (if I remember correctly).

Do you mean physically level? It's sitting on cement blocks on a concrete floor. It hasn't been moved. If it's out of level, it can't be by much or have changed much. Sorry if that comes across as my being difficult.

Steven Murray

No clue

I haven't changed anything. If my "boiler guy" changed any settings during a tune-up/cleaning, I wouldn't know. I call him, he comes during the day while I'm at work, and I pay him. Since I've had him out twice to look at the problem, you'd think he would have made a connection between some change he made and the problem, but then again, who knows?

Steven Murray

gauges

What am I looking for? I can tell you that it's not like there's a dial half-filled with water.

Steven Murray

pix

Since a picture is worth a thousand words, I figured I'd just post some photos rather than try to describe the layout. Hopefully, this will answer your questions...and lead to an answer to mine.

Leo

Did it change

Did the change begin just after your boiler guy serviced it? If not then it rules out any bad adjustments.

Leo

Brad White_9

What I see:

If I am grasping this right, the expansion tank seems to be connected to the top outlet of the boiler. The circulator (black) seems to be pumping into the boiler. (I cannot tell because the flow indication arrow is on the opposite side of the circulator.)

If for the moment I assume that is the case then the first tee into the return of the circulator comes from the return from the brazed plate exchanger. This also imposes a pressure drop on the suction side of the circulator.

I suspect if the above is the case then you are drawing air into that vent atop the circulator suction. If the circulation pattern is the opposite (that the circulator is in the boiler outlet and pumping away) then what I stated above will not apply.

Can you check and verify the flow direction?

Steven Murray

I'll check

I'll confirm the direction of the arrow on the circulator when I get home, but I'm pretty sure it's pumping away from the boiler. If it helps describe the layout, maybe this will help:

Image 457 is of the supply side of the heating loops (note the zone valves) - (I know, you know this stuff). If you think of the other pix of the boiler (except 458) as the front, then 457 is from the left. Does that make any sense?

BTW, thanks!

Brad White_9

You are probably right

now that I look at it, it does appear that the zone valves, which are almost always on the supply side do connect to that side of the circulator, so it makes sense. The expansion tank does seem to be on a dedicated outlet to the boiler, the internal air eliminator. So for all intents and purposes it is pumping away. Still, let's check. It would not be the first time that a circulator was installed backwards (not saying that is what it is). Still more information.

Such tight confines, hard to see things let alone work on them!

Brad

clammy

re reading

I was re reading your post and you mentioned that you re bleed all the zones and they where fine and a few days later you had air again ,i took a look at some of your pics and see you have just a regular taco 1/8 air vent to some that may seem to be good but in all my install i put a spriovent on the suction side of the pump with the circulator pumping away from the spriovent and my expansion tank and water feed connected to it ,by any chance are you on a well water system ,but even so when you bleed a system with cold water your hose in your bucket may tell you there's no air but after the water heats up it releases the oxygen from the water you end up with air in the system .For the last 5 to 8 years i have sold every hot water boiler suystem pumping away with a spriovent and i never have any air related promblems i have not been back for any bleeding or air related issues .if your baseboard has small manual bleeder on them then just re bleed them induvally and see if your re bleeding it from ther boiler you will always end up with some air noises for me every install deserves a good air elimator and to me any of the higher quality mirco air bubble typr air elimators always do a excellent job of removing and contuining to remove any and all air with the exception of some cast iron rad system and unusual system piping hope this helps also check to see if you pressure reducing valve is feeding any water in that would also add fresh highly oxygen ladden water into the system which once heated does release it,s oxygen back to the system causing air r3elated noise hope this helps .Peace and good luck

Jerry_15

I agree with clammy, look for a pressure drop, but first nip down to the hardware and get a 30 psi gauge attached to a female hose connector. You can make this up pretty easily if they don't have a ready-made.Hook it up to the boiler drain ( after first letting out a little water/sludge) If the pressure is dirt-dog low (I bet it is), next check the expansion tank for 12/15 psi, pump up if not, if it's dead or spits water replace, CHECK THE PRESSURE ON THE NEW ONE BEFORE FILLING THE SYSTEM. I think your problem will wind up being a bad gauge and a stuck fill valve, the test gauge will tell all quickly. If pressure is not, and x tank is ok, buy a cheap thrill and hit the fast feed to 20, or screw it down after a few gentle raps with the hammer, to fifteen. Sometimes they have a strainer, sometimes they just drop dead. I love Brad's advice, and take notes (truly!!), but it might be a little deep for an already successfully operating system. Something went south. Eliminate the easy stuff first. Keep posting, like to hear how you make out.

Ronnie

System 2000 EK-2

I think you need to flush the boiler with TSP and add 8 way boiler treatment (System 2000 sells it) this will stabilize the water after flushing out system. Also back flush the plate exchanger (See system 2000 owner's manual). You need to buy 2 quarts of 8 way as one you will add after flushing system then bring the boiler up to temp and heat to all zones then flush again and, add the other one and keep in the system. Visit energykinetics.com for your local dealer.

Weezbo

i have heard of this ...

A spirovent is a good thing..

the boiler is crooked:)

call someone who likes to install and service them.

once all that starts happening its all your fault. you bought it. its Yours. a service guy i know calls them a yellow hunk of junk.dont call him though, he might go into how he has a new sawzall and a boiler /engine cherry picker .

Steven Murray

huh?

Maybe I haven't had enough coffee yet, but I'm not sure what you're saying here.

Steven Murray

a few answers and more questions

No, it's not a well water system.

I can certainly understand how "fresh" water would release air when heated, but why is it getting trapped in the boiler and not a) rising to the top of a loop; or b) bubbling out of the vent cap?

The small manual bleeders on the radiators are spouting nothing but water.

BTW, when I say hammering, I'm not talking about some minor noises; I'm talking about serious banging that can wake you up at night.

Steven Murray

could a draft problem be at play here?

I'm not saying there are any indications like smoke or tell-tale odor, but the banging reminds me of one time a few years ago when the chimney was plugged.

Cast Iron

had same problem

My mother's energy Kinetics was short cycling for a while, same symptoms you describe as well, rumbling/banging, percolating noise in the baseboard pipes. I noticed several things.

Temp gauge going up to 220*+, pressure gauge going from 10lbs to 17 as it went up to 220*, and a rushing water sound.

It turns out the HX was old, about 15 years old, and the operating aquastat was bad.

HX was sufficiently clogged that it was causing some back presure problems, they replaced the HX and the boiling noise went away.

On our model, there are two aquastats (both White-Rodgers models), one right over the burner which is the high limit, and another, near the lower right of the burner which is the operating aquastat.

For our model:
High limit = 190* with 10* diff
Operating should be 160-70 with 10*diff.

Our operating aquastat went bad.

You should check what temp your boiler goes up to. If it's over 200, try turning down the aquastat over the burner to 170 to see how the system runs. This would assume that the operating aquastat is bad.

Good luck. This went on for almost two seasons before we were able to figure it out.

Weezbo

Steve , the air eliminators,expansion tank ,fast fill and any

"field " pipe or fittings or valves could be the culprit.

any bonnet nut on a valve can take on the ability to cause ...as guesses go first there is a cause then there is an effect. i like to eliminate some of the effects first then speculate. testing some things First then correcting these variations is also a prudent course of action.

EK do not like air..then too, a fire on steel boilers is like a fire on a thin cookie sheet the water looks like you could "Fry Water" even a cookie sheet at half the temp will buckle and make some severely non Scottish noises especially when it is "Open To Air". well, theres a quick list of my guesses. without tools and being there diagnosing the correct cause is not too easy.