Air in Baseboard heating system


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Old 01-25-16, 04:55 AM
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Air in Baseboard heating system

I have a Crown boiler that heats a 4 zone baseboard system. I have to purge the air out of the system more often than I think is normal.
By looking at a previous post on this GREAT forum, I realized that I have no air scoop on the system and the air vent is not installed at the proper location.
I will be installing the air scoop and new air vent in the near future.

My question is why is the air generated in the first place. Could I have the high limit switch on the Honeywell aquastat set too high?

Also, what do you think of NOT using an automatic fill valve. Mine is shot and I have closed the inlet valve to it. I keep an eye on the pressure and it does not move much at all.

Thanks in advance
 
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Old 01-25-16, 05:45 AM
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Purging air more often than on an initial fill and MAYBE again a few days to a week later is excessive. The most common source of air is it being entrained in make-up water. The only reason for making up water is because of excessive purging and/or leaks in the system.

I used to be in charge of about fifty "closed loop" heating and cooling systems. On every single one of them I either ran them with the make-up water off or I had a water meter installed to track how much additional water was being used. Most would go for years without any additional water and when one DID start using water we went looking for the leak.
 
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Old 01-25-16, 05:58 AM
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We would need pics of your system .. What type of expansion tank and such... Without that we can only guess..

Maybe your gauge is off and you dont have enough water in the boiler. Maybe you have old steel exp tank that needs to be drained, and the air vents are your issue..

We dont know...

Post pics and we can guide you further...
 
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Old 01-25-16, 08:26 AM
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Thanks to both of you.
For some reason this site doesn't want me to post the photos that just took. I will try to figure that out.
While taking the pictures I realized that, out of the box, the Aquastat was set to 200 degrees. I lowered it to about 190. The Aquastat is net even a year old. Maybe the water was actually at or near boiling. ?????
I replaced the old expansion tank a couple of years ago. It was an old steel tank mounted in the floor joists. In its place is a diaphragm type of expansion tank . I have not have any pressure problems and I replaced the gauge a year ago.

I am going to install an air scoop and vent. Does it HAVE TO be on the supply side? I just don't have enough horizontal 1 1/4" copper pipe to install it in and I am limited to the return side. I figure that at least it is in the system and should work.

I am not a plumber although I have had a lot of plumbing experience, years ago, in the Solar Hot water biz.
I bought this 160 year old house and try to do everything myself because "this old house" would bankrupt me if I hired people for everything. 18 years ago I took out an old oil burning heater, replaced it with the Crown, and split the system into 4 zones. This air in the water has been on on going thing but I know that it's not right. It wasn't until today that I realized that when I installed the heater that I forgot to install the air scoop. ooops.
 
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Old 01-25-16, 08:50 AM
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Old 01-25-16, 09:41 AM
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The pictures DO help!

Forget about an air scoop, you don't need one. The air is released from the water in the boiler. I dare say that you have a huge amount of air in the boiler right now because it has no way of getting out. Is there not a tapping in the side or perhaps the back where you can mount the aquastat? If not, is there another tapping on the top of the boiler? How about where the original compression (expansion) tank was piped to the boiler? I dare say that this continuing air problem started shortly after you removed the connection to the compression tank. More pictures will help.
 
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Old 01-25-16, 10:25 AM
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Remove the relief valve on the top of the boiler. Add a tee to the nipple sticking up.. Put the relief valve in the side of the tee. Add an air vent to the top of the tee..

While your at it replace the existing air vent also..

Use these types they are much better.. Its all I use..


http://www.homedepot.com/p/1-8-in-Hy...00-4/202312925

Take more pics please...
 
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Old 01-25-16, 10:34 AM
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I really like the tee idea. It makes a lot of sense. Will do!! I will also get the better air vents.
There are no other places for the Aquastat to go.

What do you guys think an optimal temperature should be?
 
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Old 01-25-16, 10:35 AM
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what do you guys think an optimal temperature should be?

180f .
 
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Old 01-25-16, 10:45 AM
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You will have to add a nipple and an elbow to the side of the tee to allow the safety valve to be mounted with the stem vertical. I would add a ball valve on top of the tee and below the vent to allow for changing the vent while underway. This will also allow you to remove the itty bitty 1/8 inch vent for gross air removal while filling the system.

And I agree with Mike that 180 is the optimal temperature unless you can comfortably heat the house with a lower temperature.
 
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Old 01-25-16, 12:10 PM
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Thank you for all your help. I am assuming that the PT valve can come with a short stem, unlike the ones that I am more familiar with like for a water heater.
I have an infrared temperature device and I measured the temp coming out of the supply side and I got 193-198 degrees. I turned the Aquastat down and will remeasure the temperature later. Maybe that temperature is contributing to more air in the system.
Thanks again. I think that I have a handle on this now
 
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Old 01-25-16, 12:26 PM
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Boiler safety valve operate strictly on pressure, no temperature probe like on a water heater safety valve.

The water temperature is having almost no effect upon the air being liberated from the water. Your boiler is not a deaerating feedwater heater (used in steam plants to remove air from the water fed to a boiler) and to really cause the air to come out of solution it would be necessary to heat the water to well above 212 degrees.
 
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Old 02-01-16, 11:48 PM
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TACO:
Mounting position – Circulator must be mounted with the motor in a horizontal position. It may be mounted
vertically with the motor up, provided that the system pressure is at least 20 psi (138 kPa).
You might want to leave a note on the expansion tank and the reducing valve.
 
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Old 12-30-17, 06:53 AM
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I need some more advice

First, I really value the wealth of knowledge available on this forum for a DIYer like me.
I am going on 18 years for this heater that I installed. It is a Crown CTPB-45 160000 Btu oil burner with a Becket AFG V1 head Oil burner. Over the years various "experts" have worked this heater and I have now decided to most of this work myself.

Last night, at 1:30 AM of course, we lost heat. While cleaning off the nozzle I noticed that the insulation on the door has broken off in some areas around the opening where the flame comes out. Will this effect the burn pattern and cause the build up on the nozzle?
Can I get the insulation or a new door somewhere, if needed?

I am expecting delivery of the Crown recommended nozzles (1.1 60W) today and I have a new set of electrodes and a Becket multipurpose tool for setting the positions of the electrodes. How exactly do you set air flow? Could that be issue?

Thanks in advance,
Gary
 
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Old 12-30-17, 12:34 PM
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p,
You really should have a combustion analyzer to set up your burner. the test equipment consists of a stack temp gauge, smoke tester, CO2 tester and draft gauge.

Without these instruments there's really no way to tell.

The missing insulation shouldn't effect the fire at all.

If the nozzle is getting sooty your assembly may be out of adjustment allowing the oil spray to hit part of the head and not burning creating soot which eventually will create a problem with ignition.

Lack of air or the wrong oil/ air mixture could cause sooting.

If you don't have a smoke tester one thing you can do to at least see if you have draft through the boiler is with the fire on, open the observation door and carefully put the back of your hand in front of it.

If you have sufficient draft you shouldn't feel the heat. If your boiler is plugged or you have insufficient draft you will feel the heat coming back at you and sometimes a lot of heat so be careful.

If you feel a lot of heat from the backdraft the problem should be looked into.

Hope this helps a little.
 
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Old 12-31-17, 12:32 PM
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Thank you, Yes, this all helps!
This model does not have an access. There is only a fixed site glass on the door that is only about an inch in diameter.
I am going to look online for some testing tools.
I ran into a friend, who works for a heating contractor, at Lowes yesterday and he looked in his Becket book for my heater and there was NO air adjustment setting listed. I gave it some more air, we'll see.
I have a 36 foot chimney but I have a good draft. When the heater is cold I get a momentary back draft but it clears quickly.
It is 16 degrees out here in Philly.
The heater is running for now so I will wait for the temps to go up in the new year to take everything out and replace the electrodes and the nozzle and do all the adjustments.
Not that this games matters, but GO EAGLES!!!
 
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Old 12-31-17, 12:44 PM
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I hope so. I took them and I haven't been doing too good so I hope I didn't jinx them.

I knew as soon as I took them they were doomed!!


https://www.beckettcorp.com/

When you go to this sight you will click on SUPPORT, then click on OEM SPEC GUIDES, then click on RESIDENTIAL OIL, then in the search bar type in your boiler. (CROWN), just crown and nothing else. Scroll to bottom of page and type in CT45 in the model box and your burner will come up or you can go to page 7.

Unfortunately it doesn't give the air settings but it does have other info and what is interesting they want your pump pressure at 140psi instead of the standard 100psi.

This is not uncommon but it is noteworthy in case somebody wants to play with that pump.

Pumps come factory set at 100psi and must be adjusted manually if the boiler or burner manufacturer wants something different and must be done using a gauge.

Low oil pressure can also cause sooting and your nozzle output is partially determined by your pump pressure.

This sight is handy to have if you have a beckett burner. It's good for all different model boilers and other info. Your buddy might find this useful if he hasn't seen it yet.
 

Last edited by spott; 12-31-17 at 03:27 PM.
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Old 01-01-18, 09:26 AM
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I didn't know that about the oil pump pressure being 100 psi by default. I'm assuming that Crown would have adjusted that but ASSUME NOTHING! I will have to get a good pressure gauge.

As far as the Eagles go. We will blame YOU! LOL
 
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Old 01-01-18, 10:29 AM
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p,
If that was bought as a packaged boiler and came with that burner installed it most likely was set up for 140 but more of a concern is if somebody worked on it or replaced it and didn't know what the boiler called for..

The boiler is made by one company and the burner another.

Nowadays when you buy a boiler you can choose the burner you want to go with it so it's up to the installer to check to make sure everything is set up right.

If you need a pump replacement for instance the new pump would come factory set at 100psi and would have to be manually adjusted when installed.

It wasn't only the Eagles. With 15.5 pts I went against my Pats, figuring they would win but not cover the spread and I got hosed there too I could go on and on. Just another quality day.
 
 

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