# pressure relief valve is leaking on boiler



## wlmpdiycr (Mar 2, 2011)

Help Please!

Short version - pressure relief valve is leaking. Tried replacing leaking pressure valve with new APOLLO Value RVW30-F Safety Relief Valve and this valve leaked water from the top after we put it on and turned the water back on. So we put the old valve back on and it is constantly dripping water. We didn't turn the unit on because pressure relief valve is leaking. The pressure is at 19. What should we do? Tired of emptying water buckets!

Long version
In March the thermostat went out. We tried to replace it, but it still didn’t work. Did a few tested and figured out it was the aquastat acting up. Called a heating tech. He came out and said the aquastat needed replacing. He replaced it and the boiler worked! But the next day we weren’t really getting good heat. So we called tech and asked it aquastat needed adjusting? Tech told us it doesn’t but he would stop by. Tech looked at pipes and touched them and told us the system wasn’t balanced. He opened the screw on one big pipe, drained the expansion tank, and then bleed the radiators. We got fantastic heat. Two days later, we noticed water near the boiler, the pressure relief valve was leaking. We were about to turn boiler off when we saw the psi was 30, but we noticed the expansion tank was off. So now we need to replace the pressure relief valve because the heating tech wants to charge us again to put on the pressure relief valve after we purchase another one! 
What is weird is the water leaking from the pressure relief valve. When we tried to replace valve, we turned off water to boiler, turned off fill valve, and expansion tank and we still got a good stream of water trickling from pressure relief valve. We know that you have to drain a little water out of boiler, but the water hasn’t stop?

Peerless Gas Boiler GEM-9958 series (1st picture)
The old pressure relief valve (2nd picture)
Apollo value RVW30-F (replacement pressure relief valve) (3rd picture)

Any advice is greatly appreciated!


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## oh'mike (Sep 18, 2009)

An HVAC guy will help soon----However---most often when the pressure relief valve dribbles it is a symptom of an expansion tank failure----

Let's see what a boiler man has to say.


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## COLDIRON (Mar 15, 2009)

Check your auto feed valve, it might be sticing open and not closing completely.


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## wlmpdiycr (Mar 2, 2011)

Is there a way to check to see if auto feed valve is not working or the expansion tank ?


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## diyorpay (Sep 21, 2010)

Flick it fast. In other words, with a bucket underneath, pull up tab and let it go, fast. Try a number of times. If any luck, it may adjust to normal.


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## beenthere (Oct 11, 2008)

A. It looks like you have the old relief valve on wrong. looks like you have its discharge port piped to the boiler. Look at it, it should be marked which end is which.


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## wlmpdiycr (Mar 2, 2011)

Is the relief valve on the second picture wrong? Its the new one we tried, but it leaked at the top when we put it on, so maybe its wrong?


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## beenthere (Oct 11, 2008)

Yes, its connected that its discharge port is connected to the boiler.


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## wlmpdiycr (Mar 2, 2011)

Is it normal to have water coming out of the pipe connected to the safety relief valve when you are trying to replace it?

we turned off water to boiler
turned off expansion tank
drained water from boiler until pressure read 0 PSI
then we put the new relief valve on wrong, but while putting it on water was coming out? Is that normal?


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## oh'mike (Sep 18, 2009)

That would be normal--the boiler and pipes are holding water----so you are draining some from the system.


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## beenthere (Oct 11, 2008)

Yep, its normal. Gotta be fast when changing them out.


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## biggles (Jan 1, 2008)

is that a cold start boiler as in it doesn't maintain the water temp but heats when stat calls? when it starts the auto feed PSI should be just readable on the guage by the time the house reaches setpoint and shuts off you should be no where near 30PSI how many floors??..the relief is doing what it was designed for.now where is that pressure coming from...flip the lever on the relief and let it flush if you need the heat running a dripping relief isn't a big thing to worry about just check the bucket but it should never flow and make up feed water...water has to expand when heated and if the EX tank isn't taking up the heated water it will show back on the boiler guage....and water will blup out of an isolated boiler when changing anything below the piping going up into the house...:wink:


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## wlmpdiycr (Mar 2, 2011)

Yes, its a cold start boiler. We have 2 floors. We haven't heated boiler yet. Was waiting to get pressure relief valve on first before we turned boiler on. 

Right now the PSI is 17. The water is on, the fill valve is on, but the expansion tank is closed. Today I will test to see if the fill valve is working. If the fill valve is okay, then we will put on pressure relief valve, the right way this time - like in picture below. If this goes well, then we will open expansion tank and turn on boiler. 

Or should I bleed each radiator before turning on boiler to make sure no air is in system? 

Are there any other thing I should do or test before I turn on boiler?


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## wlmpdiycr (Mar 2, 2011)

Should I check setting on the aquastat to make sure its okay too?


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## beenthere (Oct 11, 2008)

The 30 PSIG came from when the boiler ran with the valve to the expansion tank closed.

Cast iron rads, the aquastat can probably be set down to 160 if its not already set there or lower.


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## biggles (Jan 1, 2008)

look at the auto feed valve RED ONE on the water feed what is the setting....typical 12LBs from the factory on the lock down nut that difference as your at when cold then heating the water is pushing the relief to drip....do you know if the tech adjusted it.might want to lower the feed water make up pressure...you'll have to drain off the actual boiler water and keep adjusting the stem(turn CW looking down on the adjusting screw..one half turn at a time)till the water stops at 10-12 PSI...or slightly lower.the circ.pump does the cycling of the water thru the system and that tank has to be open to the system so it can tke the expanded water and keep that PSI below the relief trip


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## wlmpdiycr (Mar 2, 2011)

Okay, while the water to the boiler is off, the expansion tank closed we drained water out of the boiler until PSI was 0. We quickly removed the old pressure valve. Put plumber's tape on treads and put the new pressure valve on correct. NO LEAKS .... Yeaaaaaaaaa! PSI is almost 10. Then we drained the expansion tank. 

Then we open water to boiler and the expansion tank PSI is 12. We turned boiler on. But you could hear water moving in the boiler? Is this normal? We turn boiler off, PSI is 17. 

We decide to check the radiators on both floors to make sure water is in system. All but one has water, I will take time to bleed the one radiator tonight, So we figure its okay to turn back on.

We've had system on for under and hour and PSI is 22. What should we do? Still hear water movement in boiler and pressure is slowly raising?


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## wlmpdiycr (Mar 2, 2011)

PSI is now 25!!! Shutting boiler off.


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## biggles (Jan 1, 2008)

your hi pressure is coming from the cold water over feeding it should stop at 12psi as tagged check right on the feeder info tag...thats what causing the heated hi pressure...drain it down again taking the pressure off that guage turn the stem CCW up close the drain off,and let the water feed and stop then keep tweeking it CW till the guage hits 12psi cold off no heating no burner.then when you bleed the rads no circ or heat running all off.you have to have the boiler pressure gauge at 12 psi or lower COLD:wink: please realize the new relief is for heated water right when the stat satisfies at set point and should be tops 20PSI..what are you missing here work the water feed psi down to make room for the heated water...the relief is doing exactly as designed SORRY.....last post got it backwards on the PSI adjusting that water feed stem(looking down on it) its CW to raise cold water pressure and CCW to lower the pressure after a quick drain off to release the actual boiler of pressureNOTE you can't adjust the cold water feed with a hot or running boiler must be off and cold...


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## wlmpdiycr (Mar 2, 2011)

Let me make sure I understand what you think I should do to lower PSI.

1. turn of water to boiler. *Do I close expansion tank or keep it open?*
2. turn off boiler and drain it to 0 PSI.
3. loosen the hex screw nut on Pressure Reducing Water Feed Valve
4. then turn the slotted adjusting screw counterclockwise (a little) to lower the pressure.
4.5 tighten hex screw back
5. turn water to boiler back on *(and expansion tank, if I closed it)?
*6. then look to see if the pressure is around 12 PSI? How long do I wait for pressure to go up after turning water back on? 
7. repeat until I get to 12 PSI with a cold boiler.

Is this what you are saying to do?
*
*


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## COLDIRON (Mar 15, 2009)

I say replace the water auto fill valve with a new one, it really shouldn't need adjusting, usually when it keeps feeding they are replaced once you start adjusting and messing with it becomes nothing but trouble especially if your not used to doing it. Now is the time not in the dead of Winter.


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## beenthere (Oct 11, 2008)

Technically. the manual shut off valve for the auto feed is not suppose to be open, except when you are filling or bleeding the system. During normal boiler operation, its suppose to be closed.


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## wlmpdiycr (Mar 2, 2011)

Sorry I'm using wrong terminology. The auto feed valve is in the down/auto position (open for when the boiler needs water), not in the up position (when water freely flows to boiler). 

We think we should just purchase a new auto feed valve instead of chancing incorrectly adjusting the feed valve. I do have a quick question - a friend told me to try this:

1. drain water from boiler until it reaches 12 - 15 PSI
2. shut off water going to boiler
3. turn boiler on
4. watch to see if PSI gets higher, if it goes past 20 PSI - shut boiler off.
5. if it stays around 12 PSI for a few hours then its the auto feed value.
He thinks this will let me know for sure its the auto feed valve and give me a chance to warm building. Could doing this for a few hours harm the boiler? Would this let me know its the auto feed valve?


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## beenthere (Oct 11, 2008)

It won't harm the boiler. It ill indicate it may be the feed valve, but won't prove it, since it could also be a restriction in the pipe going to the expansion tank. Turning off the manual valv before the auto feed, and letting the boiler sit without running for few hours, and then seeing if the pressure increases, will tell you if its the auto feed or not.

And again, the manual feed valve is suppose to be closed at all times, unless your adding water to the boiler. Because you are bleeding rads, or refilling the system. Its not suppose to be open for normal operation. If the boiler were to spring a leak, or a rad, it would flood your house.


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## COLDIRON (Mar 15, 2009)

Are you talking about a manual fast fill valve or the hand valve that feeds the auto fill valve. If it's the latter I would leave the valve open that feeds the autofil and see if the pressure rises. If it keeps rising it's time for replacement. 99% boilers have the autofil valves open all the time, not saying it's correct but it's fact. Would rather have a flood than a blown up boiler or burnt up boiler. Homeowners for water damage.


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## beenthere (Oct 11, 2008)

COLDIRON said:


> Are you talking about a manual fast fill valve or the hand valve that feeds the auto fill valve. If it's the latter I would leave the valve open that feeds the autofil and see if the pressure rises. If it keeps rising it's time for replacement. 99% boilers have the autofil valves open all the time, not saying it's correct but it's fact. Would rather have a flood than a blown up boiler or burnt up boiler. Homeowners for water damage.


Boiler won't blow up because of low water. Plus it should have a low water cut off. If it doesn't, one should be installed. Water damage from a leak can cost more to fix then a replacing a boiler.


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## COLDIRON (Mar 15, 2009)

I would rather trust my life on a flooded house than a malfunctioning low water cutoff, or some other control subject to failure at any time. Besides if I do have a leak it will leak at 12 pounds not 60-100 pounds, I know even at 12 it will still do a job on the house. Remember washer hoses, washing machine hoses, are always subject to leak. I put my money on leaving the autofil valve open 24/7 as millions of others are. Why are autofil valves required? Please advise?


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## biggles (Jan 1, 2008)

isn't this a hot water boiler the feed stas open all the time bleeding or not the red pressure regulator will maintain 12psi.if you don't have room with heated water tripping the relief set the reg lower 5psi 7psi as long as there is water before it gets called to heat...and there is no low water cutoff on a hot water boiler only boilers with steam heat risers....lets keep it in line this guy is confused enough:thumbsup:


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## beenthere (Oct 11, 2008)

COLDIRON said:


> I would rather trust my life on a flooded house than a malfunctioning low water cutoff, or some other control subject to failure at any time. Besides if I do have a leak it will leak at 12 pounds not 60-100 pounds, I know even at 12 it will still do a job on the house. Remember washer hoses, washing machine hoses, are always subject to leak. I put my money on leaving the autofil valve open 24/7 as millions of others are. Why are autofil valves required? Please advise?


Auto fill valves are not required.

They are for filling the boiler to the required pressure after installation, or topping it off when you bleed the air out. The installer is suppose to set it to the proper pressue for the applicaton its in. And then after having filled and purged the system, close the manual valve.

They are also what has caused boilers to crack when the burner becomes a run away. Because they add cold water to a hot cast iron boiler that is too hot.

An auto fill valve won't prevent a boiler from running dry, as many become clogged, and most don't even know it doesn't work. They also cover up leaks on in floor radiant systems, and cause sink holes under the slab.


What protection do you think an auto water feed provides?


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## beenthere (Oct 11, 2008)

From the B&G installation instructions.

*WARNING:* Injecting cold water into a boiler that
has overheated due to uncontrolled firing and/or
improper water level control, can cause excessive stresses
in boiler components and possible rupture of the boiler.
This will be prevented by proper selection and installation of
a water level control and burner safety controls. The shutoff
valve at the pressure reducing valve inlet must be closed
except when filling the system, after installation, or after service.
Failure to follow these instructions could result in serious
personal injury or death and property damage.


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## COLDIRON (Mar 15, 2009)

I don't think cold water should ever be injected into a overheated Boiler and if it was installed properly the feed water would not be injected into the boiler but into the system for tempering before returning to the boiler. B & G so what they are only a manufacturer, who cares what one manufacturer's says, do you do every single thing manufacturer's say? I don't think so.

Autofil's are not required but they are on every system I have seen, it's up to the installer to set the pressure HA HA now I know why their installed.

I think they should remain open to the system until all the air is out, who knows how long that will take? A Boiler running dry is the worst another thing is if the valve is overfeeding it won't ruin the house it would come out the pressure relief valve which is usually piped to a drain or is in the basement and someone would notice it. Q Can you tell me why 99% autofil valves are left with line pressure on them or main valve feeding open. I don't' ever want a boiler running dry that's it. Don't tell me they won't blow or burn or melt down.


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## beenthere (Oct 11, 2008)

Nothing to blow if the boiler is dry. Melt down is possible on higher fired boilers that are cast iron, but few residential are fired high enough to melt cast iron. Steel boilers could melt through. But no damage to the house from melting through unless its installed in a manor that is not approved.


Number ONE reason those auto feeds your talking about are left open. Is that the installer isn't willing to take the time to bleed and purge the system like he is suppose to. A form of laziness. 


B&G is the manufacturer of pressure reducing valves, they know the reliability of them. No boiler manufacturer recommends that you leave the shut off valve to a PRV open.


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## wlmpdiycr (Mar 2, 2011)

Again,, sorry about confusion. Will post a picture of the position the pressure relief valve has been in throughout this journey, So last night I tried cutting off the water to the boiler. PSI was 1t 18, and turning on boiler. It stayed at 18 PSI for about 45 minutes, then it started going up. I shut boiler down at 25 PSI, the boiler was on for 1hour & 30 minutes. The expansion tank was open. Oh yeah, I did drain expansion tank before I cut boiler on. Both floors radiators were hot. Could the expansion tank be the problem or/and should I replace water feed valve? We don't have a low water PSI shut off.


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## wlmpdiycr (Mar 2, 2011)

the water feed valve


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## beenthere (Oct 11, 2008)

Post pic of expansion tank. And post how you drained the expansion tank. The complete process of what valves you opened and closed.


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## wlmpdiycr (Mar 2, 2011)

What are the steps in bleeding and purging the system? Maybe I'm doing a few things wrong.


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## beenthere (Oct 11, 2008)

The system, or the expansion tank?

Would need more pics of boiler and expansion tank to give better/more appropriate steps/instructions for doing it.


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## wlmpdiycr (Mar 2, 2011)

We connected a hose to the expansion tank drain, shut of the water going into the expansion tank, then open the drain. Filled a 5 gallon bucket. (the water going to the boiler was open at the time). When the water no longer came out of hose, we closed the drain, removed hose and open the connection between the boiler and expansion tank.


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## beenthere (Oct 11, 2008)

Does the shut off valve to the tank, have a vent cap on the other side of it? If not, how are you letting air into the tank to drain it?


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## wlmpdiycr (Mar 2, 2011)

What are the steps in bleeding and purging the system and the expansion tank? I will put up more pictures of the system if needed when I get home. Is there a particular picture you what me to take?


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## beenthere (Oct 11, 2008)

The piping at the boiler. So I can see if ti has a purging set up or not, and how the set up is installed to say how to do it.

If there is no vent cap on the shut off valve, you need to loosen the union between the tank and valve to let air into the tank while you drain it.


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## wlmpdiycr (Mar 2, 2011)

Never checked. Was told by a plumber that when the water coming out of hose start making a burping noise that that was are going into the hose as the water trickled out. So when I drain tank I should open up the cap in the back to let air in? How long and when do I open cap?


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## wlmpdiycr (Mar 2, 2011)

These are the pics I have on me - will send more later

1st boiler
2nd boiler
3rd shut off to expansion tank


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## beenthere (Oct 11, 2008)

When the water stop coming out of the tank, crack the cap open slowly and leave air into the tank. Leave open until no more water comes out. close cap and drain valve. Then add water to boiler until its pressure reaches 12 PSIG, if you have a 2 story house and the highest rads/heat emitters are no more then 20 foot above the boiler.

No purge set up in the boiler pics. If you have cast iron rads, they should have vents on them for you to leave the air out.


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## wlmpdiycr (Mar 2, 2011)

So when I drain the expansion tank, the PSIG should drop below 12PSI? Have cast iron rads with vents. When the boiler was off. We bleed off rads, all but two had water come out, but the boiler was off. Should it only be bleed when boiler is on?


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## beenthere (Oct 11, 2008)

It can be bleed with or without the boiler running. I prefer to do it with the boiler not running, as air can be moving in the water fast enough that it does reach the rads while your bleeding them.

How high is the top of your highest rad from the boiler. You need enough pressure to each this height.


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## wlmpdiycr (Mar 2, 2011)

I think its about 17 feet from the top of the boiler to the top of the radiator on the 2nd floor.


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## beenthere (Oct 11, 2008)

Then 12 PSIG is plenty, as that will raise a column of water to a height of 27.6 foot.


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## wlmpdiycr (Mar 2, 2011)

No vent cap on tank. But we did notice a screw above drain area. Can I open it to let air in?


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## beenthere (Oct 11, 2008)

Don't know, as i don't know what screw you see.


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## wlmpdiycr (Mar 2, 2011)

the expansion tank drain. Father has finger on it


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## wlmpdiycr (Mar 2, 2011)

and there is a hex type screw on belly of tank. We think its there to completely drain tank.


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## newtech (Mar 21, 2009)

beenthere said:


> Number ONE reason those auto feeds your talking about are left open. Is that the installer isn't willing to take the time to bleed and purge the system like he is suppose to. A form of laziness.



The only time that i will close one if the system has glycol in it.

Other wise the prv stays open..

And no it is not laziness to keep it open..


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## beenthere (Oct 11, 2008)

wlmpdiycr said:


> and there is a hex type screw on belly of tank. We think its there to completely drain tank.


No, its just another tap for different types of set ups.

Use the union on the pipe going to it from the boiler.


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## beenthere (Oct 11, 2008)

newtech said:


> The only time that i will close one if the system has glycol in it.
> 
> Other wise the prv stays open..
> 
> And no it is not laziness to keep it open..


If its ok to close it because the system has glycol in it, its ok to close it if its 100% water.

There is no good reason to leave it open. Other then a tech doesn't want to come back and add water and purge/bleed the system.

Fresh water is an enemy of boilers.


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## ben's plumbing (Oct 6, 2011)

not sure why keep shuting off expanison tank this is the part that keeps relief valve closed when heating water.....so install new relief the proper way drain expanison tank start to fill system and bleed rads....after all air is out of rads ..take pressure to about 12-14 lbs...and turn off inlet water to boiler this will isolate your feeder......boiler should work fine.....after a day open inlet valve again see if problem returns.....


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## beenthere (Oct 11, 2008)

Expansion tank is only shut off to drain it.


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## wlmpdiycr (Mar 2, 2011)

We did a few things to test system

1. checked aquastat relay: it was set to 220 so I lowered it to 180.
2. shut of water to boiler
3. checked PSI at 18
4. expansion tank open
5. put thermostat to 74

Boiler was on 90 minutes went to almost 30 PSI. Boiler shut off, house was very warm. Hasn't cycle back on yet. Checked it about 2 hours later, house still warm, PSI has dropped to 20 PSI and boiler hasn't turned back on. 

So far, with the exception of the PSI running between 18 - 28, the boiler and radiators are acting okay.

So we are thinking about replacing water feed valve, if we do, do we have to drain the boiler and radiators?

the picture below shows the water feeder valve and the water shut off to boiler

what if it turns out the water feeder valve is okay, its the shut off valve from the city water that leaks?


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## beenthere (Oct 11, 2008)

What your describing is an expansion tank that is almost full of water. You can change the PRV, but that won't correct the problem of the tank being to full.

Drain it fully.


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## ben's plumbing (Oct 6, 2011)

look to see if you can change out old expanison tank to precharged new style expanison problems gone......if old tank is going to stay in system they make a combo drain ...where it lets air in as it drains water out?????


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## COLDIRON (Mar 15, 2009)

You probably should have replaced the auto fill valve as referenced back some 50 posts ago, by the looks of that valve and the aggravation you have been going through is it worth it? A new valve is cheap as is a new expansion tank with an air separator and auto air bleed. Even if your system is old and needs replacement, in the near future you could have kept the fill valve with the new expansion tank. For less than $100 you could have done all this and still can. Not trying to make you a parts changer but sometimes things just need to be replaced.


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## wlmpdiycr (Mar 2, 2011)

I will turn off expansion tank, drain the expansion tank and open the union on the pipe going to expansion tank from the boiler to let in air while draining. (No venting cap on expansion tank)

If PSI falls below 12, while draining tank, I will turn water to boiler back on to refill to 12PSI, then shut the water off again.

Then open expansion tank and turn boiler back on.

If this works/ even if it doesn't. I will purchase a new auto fill valve and expansion tank to put on. Found out the boiler was put in 20 years ago and it won't hurt to have these new parts.

After turning boiler back on, should I bleed radiators to make sure they still have water in them?

Last night they were hot, except one, it was warm (on second floor).


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## wlmpdiycr (Mar 2, 2011)

What is a good brand expansion tank? The place I get parts from sells Extrol Boiler Expansion Tanks  by *Amtrol, in *in a 2, 4.4 or 7.6 gallon*. *How do I determine what size tank to buy?


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## beenthere (Oct 11, 2008)

Amtrol is good.




PS: Don't worry about boiler pressure while draining the expansion tank. Adjust it after you reopen the valve to the tank.


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## newtech (Mar 21, 2009)

wlmpdiycr said:


> If PSI falls below 12, while draining tank, I will turn water to boiler back on to refill to 12PSI, then shut the water off again.
> 
> Then open expansion tank and turn boiler back on.


Leave the water off until the tank is drained. Very common to see a lower pressure while draining the tank. 

You need to drain the tank, let it sit to get the air in the tank. No air or not enough air will give you higher pressures.

When this is done then you can open the valve to the tank and then turn on the water to the prv. Then it should stop at around 12psi.

If not then maybe it is better to call a pro to check it out.....


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## COLDIRON (Mar 15, 2009)

wlmpdiycr said:


> What is a good brand expansion tank? The place I get parts from sells Extrol Boiler Expansion Tanks by *Amtrol, in *in a 2, 4.4 or 7.6 gallon*. *How do I determine what size tank to buy?


Look on line for the tanks you listed there should be a tank sizing calcular that will ask you several questions, IE: gallons of water in system, temperature ranges, pressure ranges then it will give you the size tank you need.


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