Central Boiler vent cap

Rugged made
Wesspur
Advertise with us
Shop deals on ebay
Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
D

deutzman

ArboristSite Operative
Joined
Mar 12, 2010
Messages
138
Reaction score
21
Location
Cody, Virginia
I've had the water level show low several times on my Central Boiler. Start adding water and couldn't get more than a gallon in before I knew it was already full, because I could here the water in the top vent.(that's where I fill from) Yesterday I checked the water level and was 3/4" below the full mark. Figured I had a leak for sure. Checked all the connections and found no leaks. Climbed up and removed the vent cap and checked the level again and it was showing full. I then used a piece of high tensile fence wire and ran it through copper tune in the cap. Don't know what it was but got a wad of something out. That should take care of the problem till the tube gets plugged up again.

With the copper tube plugged and water temp down before the damper opened there was a vacuum and when I opened the little ball valve for the sight tube it wouldn't allow the water to come all the way up in the sight level tube.

Just thought I'd pass this little bit of info on to others that may run in to this problem. This site has help me so much by reading here that I thought it only fitting to share this.
 
I had this issue as well!! A few days before Thanksgiving I noticed the water level fluctuating quite a bit from day to day, then it showed low for a few days and I started freaking out! I also did the run around checking connections and such and finally climbed up on top and added a few gallons to find that the thing was in fact full.

Glad to know I wasn't the only one that wasn't wondering about this! I was going to be pissed if my 2 1/2 year old boiler was already crapping out! I will try the wire to see if I can find anything in there. Thanks for the tip!
 
I have owned and operated two different Central Boiler furnaces over the last 21 years. The vent caps fit loose on the vent pipe and do not seal to the steel pipe unless the pipe or the vent cap has been modified. The copper tube could become plugged from spiders or mud dobber wasps but the cap still fits so loose it is not sealed well enough to hold a vacuum. Occasionally the 1/4 inch pipe that extends from the water jacket to the water level check valve can become restricted or plugged requiring the valve to be removed to clean the 1/4" pipe. This is not likely to occur unless the corrosion inhibitor is not maintained properly. It is very important to be sure that the inhibitor level be maintained properly to pevent corrosion in the furnace and parts of the system. If inhibitor is added when the furnace is new the inhibitor level remains quite static unless water is added to the system thereby diluting the inhibitor. In a two or three year period of time there may need to be a quart or so of inhibitor added to the system if a small amount of water is added after that time period. If the water needs to be added more than a few gallons once every couple years, then there must be a leak in the system and it should be found and corrected immediately to prevent the potential of diluting the inhibitor because water is added frequently and inhibitor is not maintained. Operating the furnace with a low inhibitor level even for short periods of time can create the potential for corrosion. It is also important to replace the inhibitor test kit reagent every 4 years as there is a shelf life on that item.
 
woodheatowf said:
I have owned and operated two different Central Boiler furnaces over the last 21 years. The vent caps fit loose on the vent pipe and do not seal to the steel pipe unless the pipe or the vent cap has been modified. The copper tube could become plugged from spiders or mud dobber wasps but the cap still fits so loose it is not sealed well enough to hold a vacuum. Occasionally the 1/4 inch pipe that extends from the water jacket to the water level check valve can become restricted or plugged requiring the valve to be removed to clean the 1/4" pipe. This is not likely to occur unless the corrosion inhibitor is not maintained properly. It is very important to be sure that the inhibitor level be maintained properly to pevent corrosion in the furnace and parts of the system. If inhibitor is added when the furnace is new the inhibitor level remains quite static unless water is added to the system thereby diluting the inhibitor. In a two or three year period of time there may need to be a quart or so of inhibitor added to the system if a small amount of water is added after that time period. If the water needs to be added more than a few gallons once every couple years, then there must be a leak in the system and it should be found and corrected immediately to prevent the potential of diluting the inhibitor because water is added frequently and inhibitor is not maintained. Operating the furnace with a low inhibitor level even for short periods of time can create the potential for corrosion. It is also important to replace the inhibitor test kit reagent every 4 years as there is a shelf life on that item.
Click to expand...
OK. great. Here is a guy that has had 2 CB. I am on my 3rd year with mine and just wondered how long did your first boiler last and what model did you have? mine is a 5036.
 
bringing this thread back from the dead cause it helped me out tonight. water level showed low yesterday on my central boiler and i thought i had a leak for sure i ran all around and checked. no leaks... checked sight tube again and it was back up to normal thought it must of had an air bubble. got home tonight water level showed only half on sight tube ran around again checked for leaks all good. ate dinner got online found this thread went out and bumped up vent cap which had a little ice and snow around it and water temp was back up to full!!!! guess tomorrow ill clean out the tube for the vent cap
 
I had this problem also. I have a 5036, it's been heating for 4 years, then this thanksgiving the water level started checking at different levels almost every day. I initially thought that there was some debris in the "check valve or hose" but nothing.

Then one morning I noticed that there was a small amount of steam coming from around the base of the vent cap. I checked the water and it checked low, I bumped the vent cap off of the top of the boiler and up came the water level in the vent cap. I ran some wire through the copper tube and it was blocked.

I'm not sure if it was a wasp trying to build a home in there, minerals from the water, or dirt that got jammed in there when the wind blew the cap off a few times. Clean tube and all is well for the last months.
 
woodheatowf said:
I have owned and operated two different Central Boiler furnaces over the last 21 years. The vent caps fit loose on the vent pipe and do not seal to the steel pipe unless the pipe or the vent cap has been modified. The copper tube could become plugged from spiders or mud dobber wasps but the cap still fits so loose it is not sealed well enough to hold a vacuum.

I have a 4436 and the fill pipe is long enough for the vent cap to seat if the copper tube becomes plugged with an insect or what ever. I've had to clean mine out about 3 times per year for the last 3 years. And as others have said it will cause the water lever to show low. The bottom edge of my vent cap is about 1/2" from touching the top of the roof. It just sits on top of the pipe and is not loose.
Click to expand...
 

Similar threads

docdoc
Am I in danger of killing my whole family by poisoning from outdoor wood burning boiler water contamination?
2
Replies
33
Views
5K
sean donato
sean donato
E
Central Boiler owner w/ issues
Replies
5
Views
2K
OH_Varmntr
OH_Varmntr
A
Husqvarna 236 Vent Problem
Replies
8
Views
1K
aditzuuu
A
C
2100CD runs but surges/dies in the cut
Replies
17
Views
665
singinwoodwackr
singinwoodwackr
deanbrown
Cannot start MS260
7 8 9
Replies
177
Views
8K
ZeroJunk
ZeroJunk

Latest posts

Back
Top