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high pressure?

I have a rather small hydronic system: Weil McLain WGO-4 oil boiler in basement, with 2 AHU's each w/ hot water coils. one AHU right next to boiler and the other is on 2nd floor. 1 loop of radiant floor heat in master bathroom, and an indirect fired water heater next to boiler. total system volume is probably less than 20 or 30 gallons. i just noticed that the pressure was 50 psi and temp was 180 deg F, with all 4 zones calling for demand. the 30psi releif valve had not "popped" off. i'm concerned that something's not right. i have a service call to replace the releif valve, but my question is: why is the pressure going so high? is the expansion tank not sized properly or in the wrong place? Taco air scoop with flexcon exp tank below it, but there is not the required straight pipe diameters upstream of the air scoop. i felt the exp tank, and it was warm toward the top, but with 180 deg wtr, i would think that if it was expanding properly, it would be hot to the touch. help!

Comments

  • Ron Jr._3
    Ron Jr._3 Member Posts: 605
    More than likely

    the gauge is busted . I've been finding even brand new ones are off by 10 to 20 psi right out of the box .  



    I'd recommend keeping a boiler drain pressure gauge handy . Screws right on to a hose cock . Any big box store or plumbing supply will have it . Watts makes a nice one . 
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