OVER-PRESSURIZED water-based heating boiler

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  #1  
Old 11-05-17, 11:43 AM
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OVER-PRESSURIZED water-based heating boiler

Please advise how much I should be panicking...
I left the reducing valve open (adjusted) after purging air out of a 3-zone system. The pressure went up to 50 (maybe 55) psi and the safety valve (labeled for 30 PSI) barely let out a few drops.

Yes, I will be replacing the safety valve but as of right now, is the equipment at any risk? The pressure was up to 5 minutes while I was distracted with figuring out the incorrectly labeled pipes and wiring (previous owners made a hash out of the connections).

boiler: Weil-McLain CG-5-SPDN, MAWP, water 50 psi.
reducing valve: BG FB-38 (was left open).
Expansion tank (on return) with a Taco Air Scoop: Amtrol Extrol 30, pre-charge pressure 12 psi, max working pressure 100 psi.

Please share your advice. Should I be shutting everything off and calling a pro, or should I keep using it and just monitor for leaking?

On top of that, the circulating pump (TACO 007-BF5-JW) does not turn off unless I flip the emergency burner switch. It continues to pump even when no zone is calling and all the zone valves (TACO 571-2) are closed. It even feels hotter than the water temperature...

Thank you in advance
 

Last edited by PJmax; 11-05-17 at 11:52 AM. Reason: removed formatting
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Old 11-05-17, 11:55 AM
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Welcome to the forums.

Did you actually check the pressure tank with no system pressure ?
With 0 psi in the system...... the tank gets set for 12psi.

It sounds like your fill valve is overfilling the boiler.
Temporarily shut the water feed off to keep the system from overfilling.
 
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Old 11-05-17, 12:04 PM
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Pete,
Thank you for the lighting-fast reply.
Yes, now that I've gotten the pressure back to approx. 15 psi while operating, once I shut the system down the gauge drops down to 12 psi or so.
I have closed the water supply valve (before the reducing valve) and will keep it closed for now. Is it normal to keep it open during the heating season?
Cheers,
 
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Old 11-05-17, 12:09 PM
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Yes.... it should remain open for auto refill but if the auto refill is not shutting off it will pressurize the boiler up the city water pressure.
 
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Old 11-05-17, 12:16 PM
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Got it, thank you.
So, do you think I should be concerned about the temporary high pressure? I't been about an hour since and all seems normal...
 
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Old 11-05-17, 03:46 PM
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boiler: Weil-McLain CG-5-SPDN, MAWP, water 50 psi.

The boiler is designed to operate at 50 psi. That means that the test pressure at the factory is a minimum of 75 psi or maybe as high as 100 psi. Assuming the pressure gauge is reading correctly (many do not) it would appear that you you MIGHT have over-pressurized the boiler 5 psi from the maximum working pressure. This is nothing and would be less than any field applied test pressure.

Replace the safety valve and forget about the overpressure.

It MAY be that this was the factory installed safety valve and was set for 50 psi and THAT was why it barely dribbled. It is perfectly acceptable to replace the safety valve with a 30 psi model.
 
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Old 11-06-17, 08:58 AM
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The first thing to do is verify the actual pressure. Inaccurate gauges are common. At good DIY post on the subject is from NJtrooper:
https://www.doityourself.com/forum/b...ure-gauge.html
 
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