Puzzeling Pressure Issue

Robert O'Connor_12

Hello (W)all!
It's been a while. Hope everyone is well!

17 year old Weil-McLain fan assisted water boiler pressure increase mystery.
System has 5 zones (all B&G little red circs)
2 are radiant
1 is one pipe (monoflo)
1 indirect (30 gal)
1 tiny snowmelt zone (non priority & goes through heat exchanger)
piped primary/secondary
water is turned off (not leaking by so that takes PRV out of equation).
Expansion tank not flooded.
I isolated indirect (where I set up temporary gauge) so the indirect isn't the cause.
there are 3 pressure gauges on 3 locations, 2 on the primary loop and one set up (temporary) on indirect zones purge drain.
When boiler gets up to temperature (180*) the pressure gauge on return side of primary loop goes past 30# and relief valve on boiler weeps (discharged once last week real good too), yet supply side of primary loop (3' ft away) shows 15#'s, and temporary gauge on secondary also doesn't budge at 15#.
I purged 2 of the zones to see if maybe there was air, and drained some out of drain.
Is it even possible the inch & a quarter supply tapping is clogged in some way?
Or, could 17 yr old primary circulator ready to give up the ghost?
One thing I did notice is the water I purged was darker (brown) than I would of liked to see. Leading me to believe oxygen getting in.
Ideas?

Thanks!

Robert O'Connor/NJ

Jamie Hall

Do I assume that there is a pump in the circuit between the supply side 15 psi reading and the return side 30 psi reading? If so... something is clearly plugged up, and the reading you are getting reflects the pressure the pump is adding.

Harvey Ramer

I've heard of microbubble separators getting plugged up.

EBEBRATT-Ed

Is this a bladder tank or a compression tank?

Robert O'Connor_12

Jamie Hall said:

Do I assume that there is a pump in the circuit between the supply side 15 psi reading and the return side 30 psi reading? If so... something is clearly plugged up, and the reading you are getting reflects the pressure the pump is adding.

Yes, but 15#'s? Just seems like a lot. I always thought (at best) that circulator would maybe 6.

Robert O'Connor_12

Harvey Ramer said:

I've heard of microbubble separators getting plugged up.

The Spirovent was just recently removed and replaced with an older style air scoop. Spirovent very dirty too.

Robert O'Connor_12

EBEBRATT-Ed said:

Is this a bladder tank or a compression tank?

Bladder

STEVEusaPA

I replaced a failed bladder tank. When I removed it it was totally gunked up at the inlet. So maybe like you said, oxygen corrosion.

Robert O'Connor_12

STEVEusaPA said:

I replaced a failed bladder tank. When I removed it it was totally gunked up at the inlet. So maybe like you said, oxygen corrosion.

Based on the kind of water that was coming out of it, you might be right. The curve ball is the tank isn't original (6 yrs) but is on the inlet of the circulator. The supply side gauge is maybe 2' ft away from it. now, the 64 thousand dollar question is where did all this oxygen come from? The hose for the two zones of radiant is Onix Heatway which I thought was supposed to be without all the oxygen issues.
Thanks for you insight!

Robert O'Connor/NJ

EBEBRATT-Ed

Sounds like an expansion tank issue to me.

Steamhead

Check the rate of circulation through the boiler. The water may be moving so fast that it can't pick up enough heat from the boiler, so there may be some steam forming in there and causing the pressure spike. I've encountered this and it took longer to figure it out than I like to admit.

If the boiler is very dirty inside , steam can also form as water tries to get past the layer of gunk- just like in a water heater.

And I'm sure you've already checked the firing rate.

hot_rod

History tell us that tube has a history of slugging systems, often closing down tube and piping completely

I highly doubt the circs you defined could overflow a cast boiler

Wilth all those various zones there is somewhere to dump BTU s if you have any flow, if not the boiler will cycle off on temperature control.

Regardless I would use a strong cleaner, flush and refill.

Exp tank is a suspect, but that tube may be the key

kcopp

I have had the same issue w/ a W-Mclain GV boiler, Onix tubing. System O2 ate through the Spirovent guts. and would plug up the opening on the expansion tank. It has eaten through two extrol tanks in 6 years.
This taught me to have the customer have me go back at least every other year to add inhibitor to the system when Non- O2 barrier tubing is involved.

hot_rod

And that sludge will plug most all components in a system

ChrisJ

hot rod said:

And that sludge will plug most all components in a system

Robert O'Connor_12

I hate it when someone posts a problem, people try to help, but then the original poster never comes back and tells you the result! I'm not that guy. Just had me appendix out fellas. Not fun btw.
Anyway, changed the expansion tank but pressure still rising when it comes up to temp. I have a bad feeling it IS the tubing. The water that came out was really bad. In fact, I drained into my slop sink & it stained it so bad you'd think I poured steam boiler condensate in it from a 80 year old boiler.The smell was so raunchy and had a strong chemical smell to it. Im gonna have to completely flush entire system now, but Im a slow movi g train at the moment. How can I determine (prove) it's the hose? This is turning into a very big deal for me. I've installed miles of this hose all over North Jersey! Has anyone made any claims for this? I thought this new hose with the aluminum oxygen diffusion barrier was supposed to be the bees knees too. It certainly cost enough.

Robert O'Connor/NJ

kcopp

Good news is you are ok....

The Onix is not super great tubing but you can "fix" it.

On another post we had someone use a power flush set up to power clean the system.
You can rent it. I am not sure if Emerson Swan get down to NJ or not.
I have a number of systems out there w/ onix and polybutylene that are being kept "in check" w a yearly check up.

hot_rod

Robert O'Connor said:

I hate it when someone posts a problem, people try to help, but then the original poster never comes back and tells you the result! I'm not that guy. Just had me appendix out fellas. Not fun btw.

Anyway, changed the expansion tank but pressure still rising when it comes up to temp. I have a bad feeling it IS the tubing. The water that came out was really bad. In fact, I drained into my slop sink & it stained it so bad you'd think I poured steam boiler condensate in it from a 80 year old boiler.The smell was so raunchy and had a strong chemical smell to it. Im gonna have to completely flush entire system now, but Im a slow movi g train at the moment. How can I determine (prove) it's the hose? This is turning into a very big deal for me. I've installed miles of this hose all over North Jersey! Has anyone made any claims for this? I thought this new hose with the aluminum oxygen diffusion barrier was supposed to be the bees knees too. It certainly cost enough.



Robert O'Connor/NJ

Tough to "prove" that the hose causes sludge. But follow the logic behind the formation. O2 ingress supports the process. Now think about the places in a system where that much O2 can enter on an ongoing basis. You're an intuitive fellow, what do you come up with.

Do you see sludge formation like this in cast iron boilers connected to copper fin tube and copper pipe?

There is only one common denominator in these grossly sludge
d systems.

Talk with Dale in Bozeman, or Richardin Dillion CO, they have stories to tell.

There was talk about forming a rubber radiant chat site to try and compare data and get answers and compare lab test results, you would be the perfect host