boiler overpressurizing

Big Ed

I would check the gauge.Is its scale in pounds ?or oz.? Could also be bad but the pop safety would have poped at 15#....

I would also test to see if the pressuretrol has control on the burner.Could be wired low voltage to a stuck relay.Which would be in correct and a hazzard...

Odds are a incorrect gauge...
The .5 should be the "cut in" on a P404.. The cut out ,which is the limit is ( cut-in + the diff equals the cut-out)

TOM DUFAULT

SINGLE PIPE SYSTEM OVERPRESSURIZING

GOOD MORNING,

HAVING AN ISSUE WITH MY BOILER OVERPRESSURIZING. I FOUND IT UP TO 15LBS THE OTHER DAY, AND HAD A SINGLE RADIATOR IN THE HOME SINGING VERY LOUD, WITH ALL THE OTHER RADITORS IN THE SYSTEM BLEEDING NORMALLY. I PULLED THE MAIN BLEEDER OFF IN THE BASEMENT, AND IT SEEMED TO BE OK, PULLED THE PRESSURETROL OFF AND THE PIGTAIL, PIGTAIL WAS CLEAR, BUT THE PRESSURETROL IS NOT SHUTTING THE BOILER DOWN FOR THE OVERPRESSURE. I AM GOING TO PURCHASE A NEW PRESSURETROL AND A MAIN BLEEDER FOR THE SYSTEM, BUT I DO NOT KNOW IF THIS IS THE PROBLEM. IF I AM CORRECT, THE PRESSURETROL IS DESIGNED TO SHUT DOWN THE BOILER FOR OVERPRESSURIZATION, NOT TO REGULATE THE PRESSURE, AND THE MAIL BLEEDER WAS WORKING BLEEDING OFF UNTIL THE RETURN GOT HOT, WHICH I WAS TOLD THAT WAS PROPER. THE BOILER IS CURRENTLY RUNNING AT 5PSI AFTER MESSING WITH THE MAIN BLEEDER, AND THE PRESSURETROL IS NOT SHUTTING DOWN THE BOILER AT.5 PSI. ANY WORDS OF DEVINE INTERVENTION WOULD BE MUCH APPRECIATED!!!

TOM DUFAULT

BOILER OVERPRESSURIZING

REPLACED THE PRESSURETROL AND ALL THE BLEEDERS , INCLUDING THE MAIN VENT, AND THE SYSTEM IS NOW SHORT CYCLING BECAUSE THE PRESSURETROL IS NOW WORKING. THE ONLY THING I CAN THINK OF IS THAT THE FLAME IS TOO HIGH...... ANYONE HAVE A THOUGHT ON THIS???

TOM DUFAULT

BOILER OVERPRESSURE

THE PRESSURETROL IS CUTTING OUT THE BOILER AT THE PRESSURE MARK ON THE GAUGE + - THE DIFFERENTIAL SETTING. IT SEEMED THAT THE PRESSURE WAS ACHIEVED VERY FAST VERSUS OTHER BOILERS THAT I HAVE HAD THE PLEASURE OF WORKING ON THAT DID NOT CYCLE OFF AND ON AT SUCH A RATE, AND PRESSURE WAS NOT AN ISSUE. THIS IS A PEERLESS BOILER, SINGLE PIPE, AND INSTALLED SOME TIME IN THE 80'S. THE REASON IT CONCERNS ME IS THAT IT IS CYCLING OFF AND ON SO RAPIDLY. IS THE PRESSURETROL SUPPOSED TO BE THE MAIN CONTROL FEATURE IN THIS SYSTEM, OR IS THIS BOILER SUPPOSED TO BREATHE ON ITS OWN, MAKE HEAT, NOT PRESSUREIZE THIS WAY, AND THE PRESSURETROL IS JUST A FAILSAFE FEATURE TO SHUT THE BOILER DOWN?

Big Ed

Limit

The pressuretrol is a limit and controls the system pressure through the burner. The system does not need a lot of pressure to fill the system with steam.Most only need ounces. The build up of pressure tells the boiler "ok my radiators are full,cut the production of steam" burner off. Pressure is counter productive on producing steam .The higher the pressure ,the higher of temperature you need to produce it.True more btus ,but you don't need more to heat those old systems. I look at a steam system as a baloon.Your lungs are the burner and the baloon is the radiators.The bigger the baloon the more your lungs are pushing.If you have leaks in the baloon the more your working to maintain the size.

Ryan_10

First of all...

Stop screaming. NO MORE CAPS PLEASE. Now, why are you building so much pressure before satisfying the thermostat if you have the temperature set at a static setting? In this scenario, *MY* Pressuretrol is basically a failsafe. I only hit the limit when I try to bump up 6 degrees or something, and even then, not often. Is this a small residential system? Are the radiators getting hot all the way across and THEN the pressure is going up? If not, you've got venting issues.

Incidentally, at 15 pounds you might have nuked all the radiator vents, if they weren't junk before and causing the problem, and very like need all new ones. Pull each one and ensure that you can blow through it easily without resistance.

Ryan_10

Wait a minute again...

All the "bleeders"? You didn't go and toss hot water manual bleeders on the thing did you? Some other guy here just did that trick.

What vents do you have where (Brand/type) on how many and what size radiators? Are they actually working to vent air?

TOM DUFAULT

My apologies on the caps!!! I am in the military, and the system I work on requires caps. I did replace all of the vents with brand new vent rite non adjustable vents, and replaced the main vent on the retire with a vent rite no. 35 vent. The system is venting out of the main ontil the return/condensate line gets real hot, and then the main vent shuts off. The radiator vents are working properly upstairs, and they have not experienced the overpressure.

This system is operating an 1,100sf floor in a residential multi family home. All of the radiators are getting hot all the way across.

Steamhead (in transit)

The main vent (Vent-Rite #35)

is probably too small. Measure the length and diameter of your steam main(s) and we can tell you for sure. You should be distributing steam thru that system on a few ounces pressure. Lower pressure = less fuel burned. Properly sized main vents help a lot.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"