I could use some help with replacing expansion tank in glycol boiler system. Pic included.

[Clydesdale6]

Hi. I could use some help, as my boiler guy is backed up and has no idea when he can get to me. My pressure relief valve has been leaking and I have had to empty a 5 gallon pail a few times. I did not think this through and thought this was just a minor headache. But, I believe I diluted most of my glycol. I have a air handler in an unheated space and last night it got down to 9 degrees. The system was not heating well at first, but it then started working, after an hour and a half. I am not sure if the coil was partially frozen or if there was an air pocket. At one point I had to turn the heat on down stairs in order to get the boiler to turn on and heat the water for upstairs. I then kept the heat at 62, so it would keep turning on. I heat mostly with wood and upstairs will get to upper 50s during the night.
So, I have an expansion tank coming today. My current one is filled with water. I hit the schrader valve and some water came out, certainly not air. I want to replace that at least and see if I can stop that issue and then keep the heat on til the guy can get here. Do I just shut the ball valve on either side of the tank, unscrew it and then replace it? One valve is right below the tank and one is near the water tank. The water flows to the left in the picture. I have a 4.4 gallon 12psi tank coming today. Thanks!!

 

[Reach4]

My current one is filled with water. I hit the schrader valve and some water came out, certainly not air. I want to replace that at least and see if I can stop that issue and then keep the heat on til the guy can get here. Do I just shut the ball valve on either side of the tank, unscrew it and then replace it?

It's nice that you have those valves. Position a container to catch spilled water if you want to minimize water on the floor.

The tank will be a bit heavy to handle at arm's length.

You will want to set the air precharge to match the automatic refill pressure. They typically are shipped with 12 psi, but you can adjust.

 

[Sponsor]

 

[Fitter30]

Take few more pic top of tank and piping to see if have any valves to close.

 

[Reach4]

I think the opening on the tank is down, and the Schrader valve would be high.

That is upside down from the usual, but I think Extrol permits that.
https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1351074626254/84983_PROD_FILE.pdf says

WARNING: Mount vertically only. Do not mount
on dead-end pipe.

I do wonder what the problem would be for a dead end pipe. I could see that for potable, but why for hydronic? And for potable, the expansion tanks are often on a short dead-end pipe... Different topic, but related.

 

[Clydesdale6]

OK. I had a boiler repair friend come over and assist me with replacing the tank and the PRV. I walked him through what I planned to do on the phone the night before and he insisted on helping me out, which I greatly appreciated. I am totally capable of this repair. We shut off all the zones, shut power to the boiler, turned both valves in the picture, relieved the pressure by lifting the pressure relief valve and then unthreaded the full of water expansion tank. We then threaded on a new tank and new PRV. It heats fine. Thank you. Now the question is what to do about all the glycol that I diluted. There is literally none left. I am going to make a new thread about that later tonight. Thank you so much guys!!!!

 

[Fitter30]

Hope your using boiler/ chilled water glycol not automtive. First test the strength for freeze protection. Boiler glycol they want 30% minimum for the inhibitor package with a max % of 50%. Glycol has two ways of protection freeze and slush. Slush protection might be on the manufacturer web site or phone them ask for tech. Glycol needs to be checked after leaks and week after work.on system after it has run long enough for a good mix. Not knowing what your system holds its a guess. With boiler and pumps off could drain a.couple of gallons out, pump in couple test it in a few days. Might also what to add some boiler treatment like Rectorseal 9 way - 1 qt especially if water smells if black needs to flushed and filled measure the water drained in 5 gallon bucket to see what system holds.

 

[Clydesdale6]

Using cryotek 100. Boiler holds 5.1 gallons and we made rough measurements of all piping and we believe it will all be around 23 gallons.

 

[Fitter30]

Using cryotek 100. Boiler holds 5.1 gallons and we made rough measurements of all piping and we believe it wil

50% mix -20° burst protection. They don't recommend over 50% mix.They make pump that fits in a drill motor. Two cothes washer hoses works well. Drain out 15-20 gallons in a 5 gallon bucket gallons or just drain and measure volume. Open any air vent if their high. Would also want to check the air charge in ex tank with a 0-50 tire guage before filling.

 

[KnoxEvermere]

Hi. I could use some help, as my boiler guy is backed up and has no idea when he can get to me. My pressure relief valve has been leaking and I have had to empty a 5 gallon pail a few times. I did not think this through and thought this was just a minor headache. But, I believe I diluted most of my glycol. I have a air handler in an unheated space and last night it got down to 9 degrees. The system was not heating well at first, but it then started working, after an hour and a half. I am not sure if the coil was partially frozen or if there was an air pocket. At one point I had to turn the heat on down stairs in order to get the boiler to turn on and heat the water for upstairs. I then kept the heat at 62, so it would keep turning on. I heat mostly with wood and upstairs will get to upper 50s during the night.
So, I have an expansion tank coming today. My current one is filled with water. I hit the schrader valve and some water came out, certainly not air. I want to replace that at least and see if I can stop that issue and then keep the heat on til the guy can get here. Do I just shut the ball valve on either side of the tank, unscrew it and then replace it? One valve is right below the tank and one is near the water tank. The water flows to the left in the picture. I have a 4.4 gallon 12psi tank coming today. Thanks!!View attachment 106734 rent a lamborghini in dubai

Yeah, if water’s coming out of the Schrader, that tank is shot. If you’ve got shutoff valves, you should be able to swap it pretty easily - just make sure the new one’s pre-charged before opening it back up.