How the boiler expansion tank works

[@lmorchard]

Thanks again for your videos. This helped me understand what I needed to do to maintain the 1950's era expansion tank in our older home!

[@84953]

Nice job thanks. The expansion tank at our church had a third opening which is used to allow air into the tank. Makes the whole thing a lot faster. This of course was from a boiler that was from the early 60's - a huge behemoth, very inefficient boiler of it's time. That boiler went a long time ago, and just a few years ago the old expansion tank sprung a leak and now is replaced with one that is less than half that size.

[@matthewschultz3691]

Thanks. I have an old style one for my boiler. This helps it make more sense.

[@henryhill3778]

Excellent. Mine is in the ceiling from the 60's and this did the trick. took a long time to drain, but it worked.

[@albshore8]

Thank you sir. I have and old style set up. now i know why the blow off valve keeps popping, and its new also why the pressure keeps going up. All the other videos show the new style. thanks again for this video.

[@WanderleiSilva29]

+albshore8 i want a video made of your yo mama works....

[@71dembonesTV]

Thanks for the informative video! I was having some trouble with our condenser water expansion tank. After replacing the faulty make-up water pressure regulator, the relief valve was still opening. The pressure in the closed loop was above 30 psi. I noted the exp tank to be full of air, so i opened the airtrol and make-up valve till it was half full. The relief valve is staying shut and the pressure in the loop is holding about 16-17psi. Would excessive air cause an overpressure?

[@markwest-ck3gs]

Great video-thank you

[@quimshtgclg]

Is there an formula for sizing a expansion tank for the system?

[@wisconsinsculler]

If the expansion tank is full after each heating season, does this high filling rate indicate a problem? Thanks for the video.

[@grayfurnaceman]

It could be the tank is too small for the system. GFM

[@steventasker235]

What does an inspection opening on a large feeder tank typically look like? Is it above the water level? Or does the tank have to be drained to allow the inspection opening to be opened? Also how is it opened for example, is it bolted shut? The feed tank is at atmospheric pressure

[@chrisbruch1759]

I've bled my radiators and still when the system turns on i still get loud clanging noises in the piping throughout the house - could this be a expansion tank issue that is causing the noise?

[@grayfurnaceman]

Pex universe and engineering tool box are sites that give some numbers. Pex universe is for bladder tanks. engineering tool box os for closed expansion tanks. If you have a bladder tank that fails every few years, it is too small. For the closed tanks, if the relief valve leaks after only a few months, it is too small. Too big not seem to matter. GFM

[@l.crossjr]

What is the purpose of the expansion tank on a chiller?

[@grayfurnaceman]

Same as it is for a boiler. to compensate for them difference. GFM

[@popstream4972]

Hello I was wanting to get your thoughts on putting a ball valve on the hot water side of a water heater or if you were aware of any code that doesn't allow it?

[@grayfurnaceman]

pop stream You can do it if you like. I don't know of any code against it and if there were, a lot of water heaters would be in violation. Use a full flow valve. GFM

[@stealhty1]

Great explanation,,,, but how does the boiler knows when to feed it self with fresh water ?

[@grayfurnaceman]

+stealhty1 That is not shown in the video. There is a pressure reducer from the domestic water that adds water when the pressure goes down. Hope this helps. GFM

[@newporg6887]

Fuck man, thanks for this. It happened to me today, the old guy i was with, he knows his shit... not the greatest at explaining it... so when i got home, i wanted a more clear view of what was going on. This was perfect. Thank you.

[@heck2r27]

Do you match the pressure from the pressure reducing valve to the pressure for the expansion tank?? Or what should the pressure be for the tank

[@grayfurnaceman]

It should be matched. The tank pressure should be 12# unless the house has the boiler in a basement and has 2 or more floors above. GFM

[@Lukas-Jabs]

Hi, so I have boiler in the basement and 2 floors above. When heat is not on it stays at 17 psi when it is on goes up to 30 and pressure relief valve starts to leak. Could it be bad expansion tank ?

[@grayfurnaceman]

@@Lukas-Jabs The problem you have involves either a waterlogged expansion tank, which can be drained, or a burst bladder if you have a bladder tank. The bladder tank can be diagnosed by tapping the side of the tank. It should sound hollow. If it is heavy and sounds full, it is burst. An expansion tank will be located in the rafters of the basement. The bladder is usually located near the domestic water supply. GFM

[@Lukas-Jabs]

@@grayfurnaceman thanks for the reply. Expansion tank I have is extrol model 30 that is right above boiler. Sounds hollow what I tap it on the lower half and full on top which is fine I guess, also checked the valve at the bottom when pressed air comes out not water. Could it be just not enough psi’s in tank ? Thanks

[@grayfurnaceman]

@@Lukas-Jabs It could be. The pressure should equal the pressure you want in the system. In your case, 18#. You could also have a bladder tank that is too small. GFM

[@eton13_]

My pressure relief valve is leaking water on my crown boiler.. does this mean i need to replace my expansion tank ? its an old style tank like described here

[@grayfurnaceman]

You can drain the tank. Shut off the valve to the tank and open the drain cock. When it stops draining, you are done. GFM

[@eton13_]

@@grayfurnaceman so your saying all i need to do is bleed that expansion tank and this will stop the water leaking out of the release valve ? i had a heating company come by today they said it needed to be changed with a newer smaller expansion tank and said it would cost around $600 tank and labor included

[@grayfurnaceman]

@@eton13_ If your tank is located near the ceiling, it can be drained. The HVAC company is probably wanting to install a bladder tank. Your tank must be bled every 2 to 3 years. The bladder tank does not need to be bled. GFM

[@eton13_]

@@grayfurnaceman yes its an older tank thats literately connected in the ceiling. il bleed it and see if it helps ! thanks so much my friend have a happy new year and god bless

[@JT-qq2sg]

I put a small air hose up through the water so air could reach the top and increase the air pressure to force the water out of the tank

[@wisconsinsculler]

nice time-saving idea.

[@lagooncat]

Would water in the expansion tank effect the boiler pressure? I am sure our expansion tank needs draining, it is long over due and I will deal with that. My boiler gauge is only showing around 7.5psi, which sure be around 12psi, correct? I am having trouble getting heat to all of our rads, only 1 on the 2nd floor is working now and another on the main floor only partly heats. All was work working well until I replaced a fitting on a rad in the basement (same level as the furnace/bolier). Now that basement rad works great but troubles with the other. My uneducated guess is a lack of water in the system and low pressure, but could these problems be a result of the saturated expansion tank? Thanks.

[@grayfurnaceman]

MARK MACLEAN 12 PSI if you have a basement and 1 floor or 18 for 2 floors. The tank needs draining if the boiler pressure increases more than 3 # when the burner is on. Your system could also need bleeding. Hope this helps. GFM

[@sti2071]

What do you do if your expansion tank doesn't have the shutoff valve to the boiler. I have an old style tank and it just has a drain valve. The other end is connected to the boiler piping through a flow control valve which is old and I'm not sure it even functions properly.

[@grayfurnaceman]

Many of the older unit had this. You can drain the tank normally. Sometimes you will get air in the system that must be purged when you are done. Hope this helps. GFM

[@sti2071]

Ok thanks for the info!

[@rohitmali2510]

How to expansion tank liver oil up down?

[@laithtahseen7261]

I have problems with hot water hotel net the air in system pipe (it is 1200 m long) there are 6 relief valve in system

[@gerardmoran]

Is this Hank Hill?

[@joeurban3724]

The expansion tank in my boiler system (oil fired) has the expansion tank installed on the infeed side. So, water infeeds through the tank, then to the pump, then to the boiler and out to the zones. Is this wrong? Does it make a difference?Seems to defeat the purpose of the tank since the water coming in will be cooler than the water on the outfeed.

[@grayfurnaceman]

The expansion tank has little to do with temperature of return and supply water. It performs 2 functions. It allows a place for the water to expand as it heats and it catches air bubbles in the system. Newer bladder expansion tanks do not have the air bubbles function. Hope this helps. GFM

[@joeurban3724]

Thank you for the response. I was just wondering if it made any difference to the function of the furnace/boiler since the expansion tank is on the infeed side? shouldn't it be trapping air from the hot water coming directly out of the boiler? Or does it not matter where the tank is located?

[@grayfurnaceman]

Most of the expansion tanks in older boilers were on the supply. Newer ones that use a bladder tank often have it on the return. GFM

[@joeurban3724]

Thanks again for the response. The boiler is only about 20 years old so I guess the location is ok.

[@grayfurnaceman]

No, excessive air will only cause problems if it gets into the circulating system. Your half full tank is about right. It will probably need to have the water emptyed about every 3 to 5 years. GFM

[@walterschilling4512]

first great video, my tank is empty in the house I move into,the valve is shut off, so I open the valve to let the water in ,do I leave the valve open or close it after it fills,thanks

[@grayfurnaceman]

walter schilling Not a simple answer. There should be a pressure regulator at the water inlet. If so, It should stop at the rated pressure and it should be left on. However it may leak by. If the pressure reaches around 25#, the pressure relief valve will start to weep. If so, the reducing valve may have to be replaced. Hope this helps. GFM

[@3706123]

i have very poor hot water pressure. i also have sulfur water. Is it possible that my heating coil is clogged up and restricting my pressure? If so, can you tell me how to clear it out? Or is it something else? can you help me.

[@grayfurnaceman]

Martha Gillespie If you have a water heating arm in your boiler, yes it can get plugged. I would first make sure there is no problem at your faucets. As for how to clean it, it depends on how its made. You might send pics to [e-mail]

[@shyanndog]

Thank You

[@grayfurnaceman]

Welcome GFM

[@mortier9]

Are expansion tanks used on the modern high-efficiency condensing boiler systems?

[@grayfurnaceman]

Yes. The only difference between older and high efficiency units is the efficiency. GFM

[@TrevG18]

yes

[@egorbiletskiy2950]

You can learn more about it on woodprix website I think.

[@Miles-mf9kg]

why are you explaining non diaphragm expansion tanks if we no longer install them and haven't for awhile

[@grayfurnaceman]

Because they are still out there, and in great numbers. Repairmen don't fix new equipment. GFM

[@mattfoley6082]

@@grayfurnaceman My house was built in 1967 and has this old style expansion tank. One day I found water on the floor by the boiler. That was the day I learned about the pressure relief valve and the need to drain the expansion tank.

[@jackjenkins6305]

@@grayfurnaceman Thanks for the video. I have one in my house. I notice it is not warm at the bottom when heat is on and it sound like water is not in the expansion tank. I am thinking the value is shut off for some reason. I will have it looked at or replace it with bladder type. I do want to take a chance of a water leak or something. I do have to adjust my pressure to low (10-12) in hard winters, and 12-16 other seasons because it is a two levels house about 30-35 feet to the highest point to a radiator. Your thoughts on the expansion tank.

[@imhotep1613]

worst explanation ever. didn't get anything