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Can I retire the old B&G circulator in place?

Tom Elam
Tom Elam Member Posts: 57
I have a 50 year old natural gas fired 120k BTU boiler with the circulator mounted on the side of it. I need to set up my system to pump away. The old B&G circulator flanges look like they may be a challenge to remove due to the rust and crust on the 90° elbow on the return side of the boiler. I am looking for options so I don't open a can of worms. Here are my 3 ideas in order.

1. Can I retire the old B&G circulator in place? Since it is a centrifugal pump water will flow through the impeller. I will probably use a new Taco 007 circulator. My concern is not having enough flow through the boiler and overheating it.

2. I can remove the old circulator and cut the copper return pipe and bolt the two old circulator flanges together than spool in a new piece of copper pipe.

3. I can buy two new flanges and make a spool piece to bolt in place of the old circulator.

I am open to any suggestions.

Thanks

Comments

  • hot_rod
    hot_rod Member Posts: 18,279
    Remove it is possible, it will add some pressure drop, and may squeal some day :) Build a spool piece with two sweat pump flanges and copper tube and install the new circ pumping away.

    The new ECM circs are a nice upgrade, plenty of choices.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Tom Elam
  • icesailor
    icesailor Member Posts: 7,265
    What is so unusual about your 50 YO system with the circulator on the return, that is so bad that you need to re-pipe the system and put the circulator in the supply side? Do you think that the time, money and effort of moving that circulator will cause the heavens to open up and shower dollar bills on you?

    It won't.

    If you want to make an improvement, put a ECM circulator in place of that old Series 100. That has provided you and countless others with yeomen's service for 50 years. One of the reasons that Series 100 is mounted on the return and it has lasted so long is the cooler return water not lunching the bearing seal like happened when they are mounted on the supply.

    In MY experience.
    AlCorelliNY
  • Gordy
    Gordy Member Posts: 9,537
    edited February 2015
    So long as the pump curve matches the old b and g flow should not be an issue for the boiler. Has everything been working properly? Are you having air issues?

    If you want to pump Away from the x tank you can leave the circ on the return where it's at, and move the x tank location to the inlet of the circ.

    What type of x tank do you have now compression up in the ceiling, or diaphram/ bladder type?

    Changing x tank types changes how air is controlled. Removed verses contained at a location in the system.
  • Tinman
    Tinman Member Posts: 2,797
    All due respect Ice, I've re-piped 3 really old cast iron boilers this winter for the sole purpose of pumping away and adding a good air separator to correct constant noise and air problems. In all 3 cases, our customers were amazed by the result after initially being skeptical.

    I should add that on each job it was a small wet rotor pump or pumps on the returns, not a flat curve Series 100.
    Steve Minnich
    Tom Elam
  • Tinman
    Tinman Member Posts: 2,797
    I take that back. One of them did have a Series 100.
    Steve Minnich
    Tom Elam
  • icesailor
    icesailor Member Posts: 7,265
    edited February 2015
    I took my new car to the dealer for something. The RFT pressure monitor kept going off and telling me I had 4 flat tires. They had neglected to have one of their (Brand) Tech Genius's explain all the computerized maintenance issues of the car. A very nice young lady. I mentioned that thingy many of us figured out in the early era of computers. If something acts up, and you can't figure out why, open the case of the computer, pull out all the plugs and reinsert them. All the memory cards and controller plugs. It often solved the problem.

    A vast majority of noise complaints in heating systems I found to be from a lack of adequate pressure. Especially system noise.

    Yu replaced the fill valve when you moved the circulators. That's sort of like my re-inserting all the equipment on my old computers. Was it a bad memory card, or a bad connection. When I upgraded the memory with all new cards, was it the new connections that made it work or did I replace a bad card? I would never know.

    I do know that not that many years ago, there was, and I saw an issue with what they called "System Creep" when you put the fill valve in that location where the circulators cause the fill valve to "see" a lower pressure because of the drop in Delta P at the circulator. That of the expansion tank isn't big enough for expansion, and the pressure is set too low, the fill valve can add water to the system. Causing the Pressure Relief Valve to drip from high pressure. Something that never happens when you feed the boiler on the bottom. And the benefit of if you need to purge, you can tell if you are successful because you get hot water back when you have done a proper purge.

    Did you replaced those nasty 2 wire White-Rogers zone valves? The one to the left is a leaker. They could add system noise too.

    What is that right hand one connected to for a supply? Is that a hole for the PRV and they used it as another supply? That's usually used for a expansion tank and to get rid or air. Perhaps some air/noise came from there.

    I would say that about anything you did to that system was an improvement.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    What reason or problem have you encountered that would facilitate the pump location change? Sounds to me like a Can of Worms.
    If you're not experiencing any air related problems and the circulator still works, why not wait until you change the boiler. I mean, it's of sufficient age to warrant replacement anyway.
    You're going to encounter pressure drop by leaving it in place.
    Why not change location of expansion tank & water?
    Leave it alone. Or, at least wait till spring before fooling with this.
    Not trying to sound harsh but if you find this challenging, I'd find a pro in your area.
    icesailor
  • Tinman
    Tinman Member Posts: 2,797
    @Ice - the zone valves were removed. They served no purpose. Maybe they were someone's very bad idea for a check valve? I honestly don't know why they were there?
    Steve Minnich
  • icesailor
    icesailor Member Posts: 7,265
    Well, that's my very point. The system was so FU'ed that anything you, as a knowledgeable professional did, was an improvement. It was just BAD,BAD, BAD.

    Years ago, as I understood the issue, it was a bad thing to connect like that. Amtrol or someone started promoting using a special (expensive) fitting to hang under a air scoop and hang the bladder tank to it. You fed through the fitting in to the system, and because the circulator was then supposed to be installed on the supply, the circulator was pumping "AT" the tank. When Weil-McLain came out with their WGO boilers, they had you put the circulator on top of the boiler. You HAD to pump AT the tank. The cable was also long enough to put it on the return. I always put zone valves on the supply, circulators on the return. And fed the bottom so I could purge from one place with everything within arms reach. Because high mass cast iron boilers have so little restriction, the pressure drop at the inlet of a circulator could be higher (lower) than the pressure in the boiler of at the return purging place. I tried them all. For something to do. I never saw any system pressure creep when fed at the bottom with a properly sized bladder tank.

    I never saw an old system that couldn't be improved by doing something. Old split mains were my favorite. Perfect for two zone valves, splitting the load of the house in half. You certainly improved a pesky situation. There's never enough time to do it right. But always time for someone else to do it over.
    Tinman
  • Tom Elam
    Tom Elam Member Posts: 57
    There is nothing wrong with the boiler. My parents can hear air running through the baseboard radiators in the 3rd level loop, which is the 3 bedrooms and a bathroom. That area of the house is cooler.

    I increased the water pressure to 20 psig as a temporary fix to get them to warmer heat pump weather. Also I made an adjustment to one of the three flow control valves for the 3 loops in their system. Now the bedroom area is warmer and they don't have the noise. My parents are happy.

    The boiler input is 120k BTU and output is 96k BTU so it is around 80% efficient. The new boilers they have been quoted to replace theirs are 83% efficient. My parents will never see their payback for the new boiler, so now it is just an issue of comfort.

    My parents have a service contract with the local utility company (BGE), so every year someone comes to the their house to "bleed the air from the system". It appears to me the only thing BGE is doing by trying to push air out through the drain connections near the lowest point in the system is fill the system with freshly oxygenated water.

    I plan on setting up their system pumping away with a new Spirovent, bladder expansion tank, pressure regulator, check valve and circulator.

    Hot Rod, thank you for the advice I will make a spool piece with the flanges and copper pipe. I will look into the ECM circulators,
    I want mom and dad to be as comfortable as possible.

    Bob Bona_4
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    Great plan, Tom. Maybe this coming summer, go back and hard pipe the old circ bridge so youwon't have future flange gaskets to worry about replacing. Pipe it good now, leave room for future boiler swap if you replace with another atmospheric type. It will be basically a supply and return cut and swap.
    Tom Elam
  • icesailor
    icesailor Member Posts: 7,265
    edited February 2015
    Tom Elam said:

    There is nothing wrong with the boiler. My parents can hear air running through the baseboard radiators in the 3rd level loop, which is the 3 bedrooms and a bathroom. That area of the house is cooler.

    I increased the water pressure to 20 psig as a temporary fix to get them to warmer heat pump weather. Also I made an adjustment to one of the three flow control valves for the 3 loops in their system. Now the bedroom area is warmer and they don't have the noise. My parents are happy.



    Raising the water pressure to 20# isn't a temporary fix, it's a permanent fix. If the "Third Level" is cold, and you hear air in the pipes, the pressure in the system isn't high enough to get the water up there to be circulated. The circulator pump isn't a pump to push the water higher in the system, it is a pump meant to circulate the water through the system.



    The boiler input is 120k BTU and output is 96k BTU so it is around 80% efficient. The new boilers they have been quoted to replace theirs are 83% efficient. My parents will never see their payback for the new boiler, so now it is just an issue of comfort.

    My parents have a service contract with the local utility company (BGE), so every year someone comes to the their house to "bleed the air from the system". It appears to me the only thing BGE is doing by trying to push air out through the drain connections near the lowest point in the system is fill the system with freshly oxygenated water.



    Your parents have a "Service Contract" for NOTHING!!!. If the service person comes once a year to "bleed the air from the system", that person is incompetent!!! The "Air" comes from a lack of adequate pressure in the system. Either the boiler pressure reducing/fill valve needs to be adjusted, or replaced and the system pressure set high enough to support water at the highest point in the system.




    I plan on setting up their system pumping away with a new Spirovent, bladder expansion tank, pressure regulator, check valve and circulator.



    Raise the pressure first. If you want to spend a lot of time and money doing some un-necessary modifications, knock yourself out. Raise the pressure first. The system will work as it is supposed to be working.



    Hot Rod, thank you for the advice I will make a spool piece with the flanges and copper pipe. I will look into the ECM circulators,
    I want mom and dad to be as comfortable as possible.

  • RobG
    RobG Member Posts: 1,850
    You said that you are in BGE territory. If you end up needing a Pro you should contact @Steamhead with "All Steamed Up" out of Baltimore. Have your parents keep his number in their rolodex.
  • Tom Elam
    Tom Elam Member Posts: 57
    I read that some of these ECM circulators are backing down to less than 1 GMP flow. Will flow that low be hard on the cast iron boiler? Will it cause the boiler to cycle off and on?
  • Tom Elam
    Tom Elam Member Posts: 57
    Ice, I did raise the water pressure. However the air is still in the water, the bubbles are just smaller now or it is back in solution. My desire is to remove the air from the water. That it why I call raising the water pressure a temporary fix. The spirovent and pumping away is the way to remove the dissolved oxygen from the water.