Expansion tank correct install

asib512

Hey I’m usually always reading on these forums and learning a lot of information. I’ve been searching around hoping to find an answer to my question but i just got confused. 

I’m a new home owner and this is my 2nd winter here. I have an old Utica boiler i believe from late 1980s. All I’ve done was changed the PRV and the air vent. When i changed the PRV i added a ball valve so i can replace or do any maintenance to the expansion tank. When I changed the x-tank it wasn’t waterlogged and the air pressure from valve was 12 psi. On the other side where water enters, i see the black diaphragm and i tried to push it in but it wasn’t moving. Not sure if that’s normal. 

My question is, where the expansion tank is now, is that fine? The boiler cold pressure is 15 and usually goes up to 20 when heated. For some reason lately I’ve seen pressure up to 25. The fill valve is closed. I have to drain some water out to get it down back to 20 when hot and then i usually here water running on the baseboards. I believe the expansion tank isn’t working properly so I’m going to replace it and if i have to move it. 

I was thinking where the fill valve is at there’s a T fitting where it goes to supply pipe, to an air vent, and the other side is capped. I was thinking of removing the cap and running pipe to the air vent and either capping it or returning pipe to where the air vent is at. Would that work? The circulator would be pumping to the x-tank. 

Thank you for any advice and help!  

Here are pictures hopefully this helps. 

EdTheHeaterMan

YIKES!!! there can not be a manually operated valve between a relief valve and the boiler. That is a violation of CODE and all recognized safety practices.

You should let a professional do that work, you have shown that your knowledge of Hydronics and your boiler system can lead to potential danger in your DIY ventures.

You clearly did not understand the code book that covers relief valves on boilers.

You don't know what you don't know and that is dangerous.

HomerJSmith

HOLY COW! Putting a ball valve between the boiler and the PRV is a big,Big, BIG, NO, NO!

The only thing that should be in that PRV port is a Pressure Relief Valve within 6" of the boiler.

That is not the place to install a expansion tank, PERIOD!
Maybe I'm not seeing this right, it's morning and I haven't had my coffee.

GGross

In addition to the other comments. That relief valve needs to be piped vertically, Most PRV are designed to be installed that way, and may not function if piped in a non-vertical orientation

EdTheHeaterMan

Regarding the expansion tank (at one point you called it an explosion tank...How appropriate) there are different ways to test and check if the tank is operating properly, pushing on the diaphragm while it is disconnected from the piping is not one of them. You should have a professional that understands your system look into relocating that tank. The best practice is to put the expansion tank, the automatic water feeder and the air scoop all in the same location on the supply pipe in the following order.

Boiler supply outlet > Air Scoop with Expansion tank and fill valve > Circulator pump > zone valve manifolds to zone valves > then to the radiators > then to a return manifold > then the return inlet of the boiler.

From the information you provided to this point, I don't believe the expansion tank is defective. Just misunderstood.

asib512

I’m so glad i made this thread! You guys possibly saved my life and house! Thank you so much. 

I’m going to remove that ball valve now. 

You guys are right as much as i want to learn and do this on my own i should just call a professional and let them do it since it can be a catastrophic problem. 

Thank you all i really appreciate it!!

asib512

I removed the ball valve and basically put it back how everything was when i got the house. That is how the PRV was installed i just replaced it. Same with air vent. 

I’ll be looking and calling a professional soon. 

Thank you all for the help! 

Happy holidays 🍻

HomerJSmith

Better, but still wrong. There is a tire valve under that black cap on the top of the Amtrol Ex tank that you use to put air in the bladder side of the tank. The pressure that you put into the tank should match the pressure that your fill valve is set to. You put air in when the tank is empty of boiler water. You should check that, too.

asib512

HomerJSmith said:

Better, but still wrong. There is a tire valve under that black cap on the top of the Amtrol Ex tank that you use to put air in the bladder side of the tank. The pressure that you put into the tank should match the pressure that your fill valve is set to. You put air in when the tank is empty of boiler water. You should check that, too.

Yes I did that. When I removed the ball valve i checked the x-tank pressure and it was at 12psi. 

My water feed valve is set for 12psi. 

I have a professional coming Friday afternoon.
I’m going to ask him if my tank is upside down, schrader valve on the bottom instead of the top like mine is, but i thought I’d ask here first for a 2nd opinion. When searching online some say it doesn’t matter and some say the way mine is installed is wrong.

I appreciate any help. Thanks!

JAdams

You could have just moved the ball valve to just under the exp. tank (between the tank and the tee for the PRV. for servicing purposes.

cubbydog

Nice little star fire!

Vegas

right out of the course: Bailing Wire Mechanic 101. !!

hot_rod

Really no reason to have an expansion tank under an air purger? It puts it in the hottest spot in the system, possibly shortening the life, and it can also get debris settling onto the diaphragm under the purger.

With low pressure drop boilers the tank could certainly be on any connection into the boiler or on the return.

The Wire Nut

Wire-nut here. That wiring is worse than the plumbing was. Even if it's low voltage, it should be in some sort of conduit, and the splices should be done in a box. It's obvious water has already been spilled in that area, and you don't want the wires and connections getting wet. And the wires should be only as long as needed to make the connections, some extra as a "service loop" and then coiled into the box nice and neat. You might also want to look a Wago Lever connectors (Amazon sells them) as it will make it a lot easier to re-connect those wires, especially the multiple wire ones. It would also make a lot of sense to make some sort of diagram, so someone can service it when necessary, without having to figure out all those hoops and loops!