Very Cold

BJG

I have a Columbia Emerald Green fornance madel number EM 110. Its about 20 years old. It keeps getting air in the lines then I dont have any heat until I flush the lines. This happens every 3 to 4 days. I have tried many different companies to get this problem resolved, even the one who installed it, they cant even figure out the problem. No one want to figure out the problem they want to replace with a new one. Does anyone know what could be wrong or refer me to someone who may?

Jean-David Beyer

what could be wrong

I am not a heating contractor, but lots of things could be wrong. I assume you have a forced hot water system. Various possibilities come to mind.



1.) The pressure in your system may be too low. This is set by the supply valve that connects your system to the municipal water supply. It may be misadjusted or defective.



2.) The piping of your system may be incorrect. Generally speaking, the supply pipe from your boiler should go first to a pressure relief valve (unless there is a separate location for one in the boiler itself), then to an air eliminator, then to the circulator (if you have only one), then to the heat emitters. The expansion tank is usually connected to the bottom of the air eliminator.



3.) Does the pressure relief valve dribble water at any time? If so, the expansion tank may not be working correctly (too small, insufficient air pressure, leaky diaphragm).



Lots more, but a competent boiler technician can methodically go through the possibilities and adjust or replace what needs to be done, and even re-pipe the system if need be.



Did it always do this (for 20 years?), or did something change recently?

Gordy

What kind of emitters?

  Are they baseboard, radiant in floor heat, radiators? 



Is the boiler setup with a diaphram type expansion tank, or the old style expansion tank that hangs up in the joists?



Is the circulator on the return side of the boiler?



What type of air removal system does it have if a diaphram type expansion tank is installed?



This sounds like a small leak that is allowing air in the system under negative pressure.



Look at the top, and click on find a contractor on this web site.



Gordy

BJG

Very Cold

No it didn't do this the last 20  years. I guess its been in the last 5 years with each one getting worse.  It's mostley in the winter because it runs more. also affects the hot water in my shower. I have had it looked at many times by the same tech then changed to get another opinion, who of course charged me but gave me no answers. I did find the book on it and it was installed in 93. Still searching for answers. I guess I need to find yet another one who is willing to go through everything however my choices arfe limited. I have already used the two resources in my town.

BJG

Very Cold

its the old style expansion tank. I have baseboards that contain one pipe that runs from room to room. The circulator is in front of the unit but I dont know if it is installed on the return. A pipe has a fitting that is supposed to take out the air in the basement and nothing up stairs. A few months ago they installed another one that does not do the job either. I thought about a leak and mentioned it to the tech and he gave me a look that a woman does not know what she is talking about, and told me no. The water use to stay in the lines but now it does not and I have to keep replacing it. Is this something I could check? or is it best to find another tech?

Gordy

Indirect water heater?

Is that how you are getting your domestic hot water, or is it a sidearm.



If you have a tank style expansion tank you should not have an air removal system such as a spirovent.



I still say a slow leak that evaporates before a visual puddle is noticed.  Look for any valves fitttings joints ect. with lime deposits.  Or a boiler section could be leaking, or somewhere on the domestic side. Is any of your piping under the slab in the basement?



Did you try the find a contractor onn this site?



Gordy

BJG

Very Cold

I found 4 however they are 50 miles away. I will call one next week. My hot water is also generated from the boiler, but lately the hot water is not very hot. All pipes around the boiler are exposed, there are no pipes under the floor of the basement. I will look around for leaks. Will a very small drip cause this problem?? It seems to me that a small drip will not cause the total loss of water in the pipes, but I could be wrong. There are two things installed that help take out the air in the lines, one was installed more reciently because the old one was not doiong the job.

Gordy

Water heater

Is it an indirect. This type has a coil inside a tank to heat the water. 



 If the leak were in the coil you would see domestic water pressure enter the heating side so the relief valve would pop on the boiler. So I doubt it is that.



Are you sure the pipes are completly drained. does the pressure go to 0 on the gauge on the boiler, if so I hope you have a low water cutoff device installed. Or is there pressure 12-15 psi, and its just air bound. Is everyone sure the circulator is working?





Its hard to believe you are losing all the water from the system with out noticing a leak. Is your feeder valve always open?





Some pics would be helpful if possible.

BJG

Very Cold

The pressure guage hangs around 15 or so and I was told by a tech it is air bound because I have to add water to the system to get the air out. Please forgive me I do not know the technical terms however the tech showed me to turn off the valve to keep the water from coming into the boiler and flip over the switch that lets water into the system to force out the water and air. I am working on pictures, out of practice down loading from my camera. I will post soon. Thanks for your help. I want to learn as much as I can before I have someone else come out next week.

Fortunat

air elimination

to re-iterate what someone else has already said:



if you have an older (non bladder) expansion tank, your system shouldn't have air elimination in it, or you'll constantly lose the air from the tank through the vent.



If the tech is coming back out, consider having them install a new diaphragm expansion tank. That might not solve this particular problem, but it does eliminate a lot of other headaches and is fairly cheap.



~Fortunat

www.revisionenergy.com

Gordy

purging

 Yes you have to add water in order to purge the lines.  If your baseboard is in series he should start at the farthest bleeder, and work his way back to the boiler. Doing this with the circulator off. If this is a multi story start at the top floor farthest point working you way down to the boiler. again with the circulator off.



If you do this with the circulator on you are just chasing bound up air all over the system. Adding water chasing air ect.



 You are not losing water out of the system, other than what comes out as you are bleeding air. But rather water is taking the place of trapped air in the pipes. 



  You should not have any automatic air vents in your system with a non bladder type x tank. There should be a tanktrol fitting on the tank that keeps the air in the tank. The tank should be 2/3 full of water.



But since you have the air removal installed, as Fortunat says install a diaphram type x tank so that part is not a waste.



Gordy