Pressure Relief Valve and Boiler Water

Nick_28

I have a 11 yr old Utica Starfire III boiler and it has two zones for two lenox air handlers in attic and one zone for phase III indirect 45 gal tankless coil. The pressure relief valve has been changed twice and it keeps dripping. The boiler was cleaned by a technician recently and he said it was replaced as the unit did finally stop dripping water only for a week and now it started again. It has been a little over a week and there is over a gallon of water in a five gallon pail dripping from this valve. The boiler temps get to about 200 degrees and the pressure hits 30. Not sure what is causing the problem.



Also.. does anyone know what is inside boiler water that can make the lawn grass dead? The helper dumped 2 pails of boiler water on my front lawn when he replaced the hot water circulator and now the lawn is brown where you can see the large burn mark splash. Can I neutralize the soil or grass? Or wait till the spring to fertilize the area? What is in the water to make it do that? He told me it shouldn't be anything bad in the boiler water so the next time he came to swap out the circulator for the second time he threw the water in the street this time.



thanks

Nick_28

Boiler Pressure Relief Valve

Awesome... will post a couple of pics to get an idea. The feed valve was replaced a couple of years ago and the tank is empty when I tap on the unit. Will check to see if I can check the pressure with gauge. Thanks..

Ron Jr._3

More than likely

the Phase 3 is leaking domestic water into the boiler side , causing the boiler to overpressurise . Are there shutoffs on the supply and return piping from the boiler to the indirect ? The only way to rule that out is to shut the valves , pull the indirect wire and see if the pressure still rises .



Regular boiler water should not effect the lawn at all . Unless it was hot water ? That'll burn it for sure .

Nick_28

Pressure Relief Valve

The temps vary and as you can see on pics the range for pressure as well. The phase III was isolated to see if there was a leak and was told no leak to the boiler. The gasket needs changing as you can see the water stain/droplet on the face of boiler. Still wondering why pressure is up so high if the valves all hold and nothing checks out wrong from what I've been told. I was getting use to manually relieving the pressure from the domestic hot water valve and emptying the bucket every other week for the last two plus years. This shouldn't be running this way as it is obvious with the temps up and down and water bucket brigade.

icesailor

PRV Leaking

The Extrol tank is too small for a cold start boiler. You need to switch it out to a Amtrol #60 for more expansion room. And when you have the system at "0" pressure, take a tire guage and check the pre-charge on the #30 Extrol. It must be the system pressure or slightly lower. If the pressure is much lower than 12# PSIG, the tank may be failing. Atter 11 years, you could replace it. If it is still good, you can connect them both for more room. If it was a warm start, you might get away with it but not with a cold start. There is not enough room for hydraulic expansion in the system. If you have a air handler in the attic, you probably need higher system pressurs than 12#. 27' above the gauge, there will be zero pressure.

Also, if you have crappy water, that cast iron Taco fill valve could be leaking bye. I would switch it to a brass one. I don't remember what the Taco number is but you can only ger Watts 1156F's in brass.

Nick_28

PRV

Thank you! Interesting point of view and suggested correction will take serious for change. I do need to lower the temp on the aqua stat  to get it lower than 200. 

Big Ed_4

PhasIII

As Ron Has mentioned , Isolate the indirect and see if pressures settle.... they are noted to have leaky welds ....

Charlie from wmass

Note that fresh water eats boilers

I do wish you found this site earlier, if you have been doing bucket brigade for 2 years there is a good chance for heavy mineral and scale build up in the boiler. Also the expansion tank is quite small mostly due to the Phase III as it holds a fair volume of water that needs room to expand to. If you tap the tank and it sounds like a bell it is likely not shot yet but if it is a dull thud it is often toast. I prefer using 2- #30 tanks to one # 60. but either will work.

billtwocase

killin grass

The hot water will do that. I think the #30 size is fine, may be over or under charged, also as Ron said, isolate the Phase 3 and leave it off (heating sides) and see what happens. I've run into bad extrols that the diaphram wouldn't compress as the pressure rose. There could be a few things that cause pressure problems. I wouldn't disregard the feed valve because it is only 2 years old, they can be defective. Testing it would be to take the pressure off the boiler, feed in 15 lbs, and shut it off.  Let us know what you find

Nick_28

PRV and Phase III

Thanks guys for the feedback as I tried lowering the temp on

the aquastat on the boiler by a couple of degrees. It now shuts off at 180 and

the temp slowly rises to 190 inching to slightly under 195 degrees instead of

200.



The technician's assistant I believe did shut the feed valve the last time he

was there to replace the Taco temp circ with the original 2nd replacement Taco with

a new Wilo circulator. I know..Sounds confusing.. huh... anyway..  He said

he and his assistant isolated the Phase III and deemed it wasn't leaking. After

he left, the pressure stayed steady at 15-20 psi and not higher than that. Then

within ~two - four days, it slowly crept up again to 30 psi where the PRV drips

into a bucket. The PRV somewhat looks like it was the same one that was

originally replaced two years ago and the tech said he flushed it out and was

working fine. Then again, I was told DON'T touch it… I don’t know if it had been replaced which perhaps that is not the case??



I generally have a rule to not touch something I'm told don't touch. That is

why I won't touch the PRV to relieve the pressure. In the building code field,

we're taught that if you touch something and it breaks, it’s yours! Since it is my

house... I would have to pay anyway and I hate paying twice nevertheless three

times. I don't also like to sit there and watch people work as I think it makes

them feel uncomfortable as I generally will walk away leaving them to do the

business that they are in. As to be expected, sometimes it is important to

learn and ask questions no matter how they feel you are watching over their

shoulder. Every day is a learning experience so why not be involved. I think

honesty is important in any business and open communications are a must to

share with the client. Not that the motto should be the "customer is always

right" but at least the respect and utmost professionalism should stand out to

where, if I were doing work for someone, I would want the best as if I am doing

it for myself in my own home.



OK .. back to the boiler...



The boiler plate gasket to the aquastat is leaking at the top which appears to

have alot of white stuff dripping on the face of boiler. Is that calcium

deposits? How difficult is it to replace and should I have the extrol tank

sized up to 60 psi at the same time? I did tap on the 30 gal tank and it has an

empty pitch sound when I tap on it. It doesn't sound water logged at all.  Also do they make a replacement external insulated jacket for the phase III 45 gallon tank? The foam was crushed by leaning on it and now you can feel the heat transfer on the surface of the original insulated jacket where it was crushed.



My next future challenge may be relocating an air handler to allow attic access

to the unit rather than a coat closet roof scuttle with a ladder. Then again,

the two Lenox units are working fine up there in the attic but one pet peeve is

the installer Cool P__ , didn't put a return in three of the bedrooms on one

end of the house. Instead they installed a return air in the hallway outside

the three rooms. So when you close off the bedroom doors, the rooms overheat

which my kids love because it’s close to 72 degrees, but the Programmable

t'stat in my room 50 feet down the hall is satisfied with the 65 it is set at.

There is a return in master bedroom which balances the temps accordingly. Now I

am wondering how to retrofit the three bedrooms to have each a return but one filter

bank to take care of that unit exhaust.



0n that note...about the grass.. it is burnt from the boiler water which I am

unhappy about since it was my front lawn, BUT not overly worried as I will deal

with that in the spring and hope to restore it with some miracle grow!

billtwocase

let them repair the lawn

That's a given not to pour hot water, or even the old stagnant water from the system on a lawn. They should have know that, and should make it good. I've always found a mulch area, or out in the street in a drain to empty buckets. Sounds like they are charging you for their education? 

Nick_28

PRV and Boiler Water

You are right about that, that is why I asked the question what is in it to make that happen and was told nothing would harm it. Second time they came back they dumped it in the road. Most important thing dealing with people is honesty no matter which side of the table you're talking from. Otherwise how comfortable do you feel to have them come back in your home. I don't judge people with a fine tooth comb but I believe in sticking with people you can trust hence the reason why I trust the guy that does my brakes on my car!

thanks for the feedback..

Charlie from wmass

Nick the basic test for the tank is this

1. cklose the feed valve to the boiler.

2. drain the water pressure down to a zero reading on the gauge.

3. use a tire gauge and check on the air valve on the bottom of the tank. it should be 12 pounds to 15 pounds depending on your feed pressure.

The PRV may be crusted up if it has been going for a while now.

I actually just had this issue at my fathers house and I charged the extrol tank and it is all set again. I was ready to replace feed valves and tankless coils and expansion tanks. With your system being an air handler system the 30 may be fine, I prefer a bit more room but enough is enough. It work for 9 years no issue so it must be ok for size.

Nick_28

PRV

Wow thanks!.. what if it doesn't read 12-15 psi at the tank after draining the system down? 

Charlie from wmass

Try pumping it up as you do a tire

If water comes out of the valve stem go buy a new tank.

Nick_28

Pumping Away

Thanks Charlie!

World Plumber

Another test

After you check the expansion tank and bring the boiler back to the 12 to 15 PSI state close the valve before your feeder valve. Then watch your pressure it should hold steady. after several days open the valve and watch to see if the pressure starts to creep up. Generally it's either the expansion tank went bad or the feeder valve is overfilling the system many times both.

     Did this start after you had the circulator changed? If so get a new feeder valve. After they sit and rust for a while. They usually don't seat completely because  rust or debris  gets in the seat.

World Plumber

Picture

Is the expansion tank hanging from just the pipe? If so I would advise adding a support. I've seen the bladder fail and the weight break the pipe when hung like that. Even if it's a piece of strap iron next to the elbow and run up to the ceiling joist. something to keep the weight of a tank of water from bending the pipe down and breaking it.

Nick_28

PRV

Good observation which it is suspended from black iron pipe. I am sure I can add metal strap to the floor joist. thanks!

Nick_28

Relief

OK...wow.. what a difference.. I shut the water supply valve feed, relieved the pressure from 32 psi down to 15 - 18 psi, brought temp down to 180 after its fired up, and now pressure is maintained at ~15 - 18 psi. The PRV still drips but nothing as drastic as before. So after four weeks since last repair, I probably emptied close to 8 - 9 gals of water that dripped from the PRV. Bucket brigade finally at some resting point! Time for the holiday cheer!

icesailor

Dripping PRV:

The PRV shouldn't drip at all. If the system shows nothing over 18# and the PRV is driping, the valve needs to be replaced. If it drips, water must be added. Added water = failed boiler. Fix the PRV now or replace tghe boiler later.

Nick_28

Drip

Yesss... thanks for the tip on the drip! 

World Plumber

Sadly

Sadly Once a PRV has opened they sometimes will not always seal again. Try pushing in on the stem and rotating the handle, Not lifting to open. Sometimes they will reset that way.  

Nick_28

Feed Valve

Well, the feed valve was closed two days and pressure was relieved down to ~18 psi and temp at 180  max. Two days later, psi up to 25 and boiler gauge temp 190 and prv drips ever so. Hmmm... frustrating to say the least...

icesailor

Altitude, Extrols & leaking PRV's

Again,

Put a #60 or equal #60 Extrol tank. A #30 is too small for a cold start and the height of the air handlers above the boiler.

You don't have enough room for expansion and contraction.

Ron Jr._3

Semi - simple test

to see if the expansion tank is sized right ( without going into the math ) .



Make sure the expansion tank is charged the the psi you want it at . Fill and purge the system ( cold water ) .After that make sure the boiler is at the pressure you'd normally want it at ( 12 psi typical ) , and fire it up . Once it hits the high limit , check the pressure again . If it's close or past 25 psi , I'd recommend adding another tank or going with a 60 like Ice said . Around here , 2 - 30 Extrols cost less than a 60 and are more readily available ............



Personally , we use many 15 Extrols on boilers rated 100,000 btus or less ( space restrictions ) . For the most part they stay under the 20 psi threshold when heating from 60 degrees to 180 . Homes like in this pic we have to tuck one in above the boiler horizontally on the right . My own Peerless has a 15 Extrol and last I checked was at 18 psi  ( cold start oil boiler ) .

billtwocase

I would check

The air pressure in the extrol. I don't see those results yet, and have also found them over charged, which will cause the same pressure problem.

Nick_28

Aquastat

I lowered the temp on the aquastat to 160 and the temp rises to 185 and eventually falls to about 160. whats that all about? shouldn't it max at 160 if it is set?

billtwocase

there is

what's called residual heat going on. Nothing to be concerned about. The gauge is usually the highest point on the boiler. The control is shutting down the boiler at 160, but the chamber, etc will still give off enough residual heat to drive it up a little more. Gauges are also not an exact pressure and temp displaying device. They can be off on one or both of their functions. 

JPD

Coil trouble

I am pretty sure you have a pinhole in your water coil leaking into the boiler. Water pressure is 50-70 p.s.i. and will pressurize your boiler through the indirect water heater you have over time. You said the guys tested it and it was o.k.? In most situations where there is  a small enough pinhole it can take days to pressurize the system. I would try shutting the feed and return valves off to the unit and see if it rises at all over a few days. I know cold showers do not sound nice but after everything else you have done this seems like a step that needs to be taken. Hope this helps and there is no way those guys tested it properly if they were there for any short amount of time.

JPD

Coil trouble

I am pretty sure you have a pinhole in your water coil leaking into the boiler. Water pressure is 50-70 p.s.i. and will pressurize your boiler through the indirect water heater you have over time. You said the guys tested it and it was o.k.? In most situations where there is  a small enough pinhole it can take days to pressurize the system. I would try shutting the feed and return valves off to the unit and see if it rises at all over a few days. I know cold showers do not sound nice but after everything else you have done this seems like a step that needs to be taken. Hope this helps and there is no way those guys tested it properly if they were there for any short amount of time.

Nick_28

PRV Final Update

Well.. I wanna thank everyone for commenting with your feedback several months ago on this post. Problem solved with replacement of the indirect hot water heater that had a hole in it pushing the water pressure to 30+. With that said, 15 psi and normal temps...





End of Story!..Cheers

Ron Jr._3

No more bucket brigade !

Thanks for getting back to us with the solution !