MPO - 5 section , 6 zones

Burnham MPO

I wish they would sell the MPO line in a knockdown version . We received the boiler from our supplier with the jacket already damaged . It's very easy to rip the sides of the jacket where the screws hold it in place . A little creative thinking and we fixed the problem .

Me and Kenny went back for a 2nd day to wrap it up . Odd thing happened on the intial firing . Either the aquastat hung up on the first call of heat , or there was an overide . Somehow the boiler temp got to 235 degrees . This was after we reset the high limit to 180 . We ran the boiler 5 or 6 more times but couldn't duplicate what happened . Has anyone had such a temp override with the MPO before ?

Other than those 2 little details , the job went smooth . We busted our butts ripping that monster out and setting the new one in place in less than 3 hours . Needless to say , the rest of the 1st day everyone was exhausted .

Chris

The Alliance is one HEAVY indirect . Forget about handtrucking the 50 gallon or bigger down a flight of steps . I do like the levelling legs - just spin them in or out to get the tank straight . They don't have a lifetime warantee like other brands . So far after 3 years or so of installing them , they're all going good .

The homeowner didn't give us an attaboy . All he was concerned about was shoving the boiler as close to the wall as possible and changing that water filter to the right of the boiler . He tried twisting it off while we're still working - ad while it's still live . I stopped him and told him we'd try to spin it out later . The lady of the house was real sweet though , kept asking us if we wanted drinks .

Thanks alot Chris .

Haha

You got it right . We have dozens of them left over from the hanging GEs we replace . We don't use them on those jobs because the boiler switch is literally 2 feet away from the boiler , easily reached when working on the burner . Thanks alot Dave .

Ron

The relief valve needs to be piped into either one of the 3/4" tappings in the return manifold. We give you two to be able to cover all return pipe configurations such as straight down, from the left or from the right. The return fitting reduces the flow from the 1-1/2" connection and chokes it down through the 3/4" nozzle (nipple) to create a venturi effect within the boiler. It will speed up the discharge velocity of the water through the top nipple port where the rear section joins the first intermediate section from the rear. As that velocity is increased, there will be a veturi effect at that point creating a low pressure point which actually pulls much hotter water from the rear section in and around the nozzle to blend with the cooler return water to warm it up. From there the warmed up return water goes forward and down through all of the sections forward of the rear section where it all joins together in the bottom of the boiler at the bottom nipple port. The flow then goes through the bottom nipple port to the bottom of the rear section where it turns 90 degrees and up the rear section to the supply manifold connection. most of it goes on out to the system and some of it gets pulled back into the top of the boiler by the return water venturi effect.

I discussed this situation you had with the override today with our engineers and they agree that the smaller inner area of a standard tee may be the cause. If you look at the inside of the supply manifold it is fairly large at the point where the aquastat well inserts into thus keeping the well a good distance in all dirctions away from possible cooler metal surfaces. This would also explain why it didn't do again after the boiler warmed up. I have been advising to use a fair quantity of teflon tape on the threads of the supply manifold and then to apply teflon paste as well over the tape (teflon on teflon). This will ensure a good snug and leakproof connection without having to overtighten the manifold. By the way....how are you and Kenny liking the built in leveling bolts? Now you don't need that box of electrical cover plates, flattened copper or steel washers anymore to level the boiler up!
Keep up the great work and I hope to see you soon. I'll be down in Maspeth at the end of the month with some of your service people.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Might have been

condensation from filling it up with cold water . I noticed it too . Not wet , just damp .

OK

We have to go back to run new oil lines , I'll change the relief valve spot to the return tee . What I meant to ask is why such a large tapping in the boiler ( 2 inch ) , if the nozzle chokes the flow down to 3/4 anyway ? Is there an application where a bigger nozzle-nipple would be used ?

The well insertion depth was right on the money - right in the middle of a 1-1/2 inch cross tee . I think what might have happened is in my reply to Weezbo , but in that scenerio I'm not sure how the LWCO wouldn't trip . Very strange , and I'm guessing it was one of those fluke occurances . Something you see once in a lifetime . The aquastat comes from the factory preset at 200 ?

Hahaha

Now that is funny , Glenn . Holohan's magic dust . Thanks I needed a good laugh after this week .

Lchmb , the room was kind of tight , maybe 7 by 12 and a built in work bench to the left of the heater . I really wanted to push the beast to the side and let they kids rip it out , but ... no room . I have to talk to my manager about these big ripouts . Somehow me and Kenny never learned to pace ourselves , so we go full force till the boiler is out . Thats all well and good except we're pretty much shot for a few days after . Those days of feeling indestructible are long gone .

Just figured it out

Obvious all along , I'm so dense . The reason the aquastat overrode the first time was that even though the boiler was full of water , there was no flow past the well - the indirect zone was full of air . I remember opening the valves to the indirect and opening the airscoop cap . What I didn't do was purge the indirect zone , or any other zone . After a few minutes of firing I felt the indirect return pipe was lukewarm . The aquastat finally picked up a temp reading from the steam . Doh !!!!!