Repairing a 40 year old circulator pump

genericnj

ha yeah it has been an interesting adventure ...

@mattmia2 I tried as you instructed -
1. the knob/cap on top of the vent coming out of top of boiler doesnt want to turn at all.
2. I tried the pressure release valve and it moves up and down but with 0 resistence and nothing comes out - no air or water... am I supposed to do this while boiler is heated? because i did it when it was cooled down and not running.

regarding replacing the flange bolts - it would have been hell to get to the bottom ones

mattmia2 said:

I assumed they built it up to the top of the boiler then slid it back in the closet but I'm better at seeing where stuff is going to end up before it gets there than most so maybe they did it the hard way.

If you managed to disassemble the circulator you could have removed and replaced the 4 flange bolts and swapped the circulator.

Dave H_2

Something I would like to add and it looks like you had a lot of good help on this. I get this call a couple times a year;
"I can't a 007-f3 circulator anywhere. I've called and searched every possible option and all anyone has is a 007-f5. Help please"
The difference between an -f3 and -f5 is just a manufacturing code for up at Taco. A -f3 part number has been superseded with an -f5 and that's it. They are essentially the same circulator. A 007 is a 007 is a 007. There are different flange configurations, materials and such but try not to get hung up on the last numbers.
Here is a webinar that discusses circulator replacement without doing the math


As Steve said above, I may not have wanted to use a "new old" stock, you never know the state if the internal bearings and parts and will you may not get the same life as you did for the one previously used.

genericnj

For sure - I was wondering same thing when I first started looking for an f3 and only saw f5s The one reason I could not use an f5 while retaining the original f3 flange is that the mount is different (screws on f3 go in from flange side and into the pump casing, on f5 the screws go in from the casing side and seat into the flange). I was very lucky to get the new old stock and it literally appeared to be in perfect condition. I hope it lasts as long as original

Now I just have to figure out the relief valve fiasco. This boiler is a gift that keeps on giving!

Dave H_2 said:

Something I would like to add and it looks like you had a lot of good help on this. I get this call a couple times a year;
"I can't a 007-f3 circulator anywhere. I've called and searched every possible option and all anyone has is a 007-f5. Help please"
The difference between an -f3 and -f5 is just a manufacturing code for up at Taco. A -f3 part number has been superseded with an -f5 and that's it. They are essentially the same circulator. A 007 is a 007 is a 007. There are different flange configurations, materials and such but try not to get hung up on the last numbers.
Here is a webinar that discusses circulator replacement without doing the math


As Steve said above, I may not have wanted to use a "new old" stock, you never know the state if the internal bearings and parts and will you may not get the same life as you did for the one previously used.

mattmia2

Are you sure there is pressure in the boiler? No pressure, nothing comes out the relief valve, although it isn't unusual for them to corrode shut if neglected for decades either.

genericnj

Very possible that there is no pressure in the boiler right now since I left it off after testing the pump until the gauge arrives tomorrow. I will connect the gauge tomorrow and then see if that shows anything. What should the pressure be with the boiler off?

mattmia2 said:

Are you sure there is pressure in the boiler? No pressure, nothing comes out the relief valve, although it isn't unusual for them to corrode shut if neglected for decades either.

mattmia2

12 psi is the standard unless you are dealing with more than a 2 story house or some other situation where the highest piping is higher above the boiler than normal. 12 psi is the cold fill, it will go up some as it heats and the water expands against the air in the expansion tank. If it goes up near 30 psi when it is hot then there is something wrong with your expansion tank. Since your system still has air trapped in it and has fresh water with dissolved air in it, you will have to keep checking on it for a few days until it works all that air out(and add water manually if the pressure reducing valve isn't adding it correctly).

You might try some pliers on that cap on the air vent on the boiler to get the air out of that section. You probably want to ultimately replace it but you can work with the cap to get things restarted.

genericnj

Thanks I will start with 12psi and monitor it. I actually bought another vent and it arrives tomorrow so will also swap that old crusty one out. Quick q, do i need to drain the boiler again to swap out that vent or just shut off the zone valves and will i be able to remove the vent without having water shoot out of the hole?

mattmia2

well. you need to bring the pressure to 0. if you have the new one ready to go with tape/dope on the threads you can unscrew the old one with a rage around the hole and quickly screw the new one in and you won't lose much water. It will more dribble slowly out a hole like that.

genericnj

ok so I had a not so fun experience I got the gauge, made sure boiler is at 0 pressure, first I changed the auto vent on top of the boiler - no issues, tiny bit of water came out. Then i started to fill the boiler and all looked good - it seemed to slow down or stop around 10 psi (gauge sucks since its a 200 psi gauge) .... and then i decided to test the pressure release valve - nothing was happening when i would lift the tab, then i pulled on it hard and it released and water started to come out and after I closed it, water kept coming out of the top of the valve and the pipe attached to it. I quickly reconnected the drain and redrained to 0 psi and the leak is under control.... So i have a pressure release valve i ordered ready to install to replace that old broken one, but alas i realized I got one that is female thread and the pipe on the boiler wants male thread. I checked local lowes and home depot but they dont have one in stock without ordering to ship. So my question....

Would it be ok for me to put a 2 ft pipe into the female on the boiler elbow and have the pressure release valve attached at the top of that or would that make it not work right because air would be trapped there? Or should I get a male to male 3/4 nipple like this one? https://www.lowes.com/pd/B-K-3-4-in-Threaded-Male-Adapter-Nipple-Fitting/1000505665 from local lowes?

mattmia2 said:

well. you need to bring the pressure to 0. if you have the new one ready to go with tape/dope on the threads you can unscrew the old one with a rage around the hole and quickly screw the new one in and you won't lose much water. It will more dribble slowly out a hole like that.

genericnj

Update - it looks like the relief valve I got from amz was a crossthreaded return.... no wonder it was last one so going to have to find another relief valve and try again... getting close to getting this project done, I can feel the heat already

mattmia2

You can use a nipple in to the boiler. I would make it long enough that you can grab it with a pipe wrench to remove it if you have to. The discharge should be within 6" of the floor so the hot water isn't up where it can scald someone.

mattmia2

You can put a wide array of fittings between the boiler and the relief valve as long as you don't put a valve between it and the boiler or reduce the size and the discharge is within 6" of the floor or an indirect drain and the discharge end is unthreaded.

genericnj

thx - originally I had bought a small nipple to mount it but quickly realized the relief valve had damaged threads - i wish I checked before i drove out to Lowes to get the nipple for nothing .... going to get another relief valve this weekend, the closest lowes that has one in stock near me is unfortunately about an hr and half drive so I probably will have to do it on saturday. Getting there slowly but surely... thank you again, you have been so helpful!!!

mattmia2 said:

You can put a wide array of fittings between the boiler and the relief valve as long as you don't put a valve between it and the boiler or reduce the size and the discharge is within 6" of the floor or an indirect drain and the discharge end is unthreaded.

mattmia2

Supplyhouse.com has numerous warehouses and will tell you a delivery date if you put an item in the cart and give them an address. could be worth it to pay shipping to avoid driving 3 hours.

ratio

I'm trying not to sound like a fanboi but I've had nothing but good experiences with supplyhouse.com. They've got a warehouse locally & I've actually received things the same day.

genericnj

mattmia2 said:

Supplyhouse.com has numerous warehouses and will tell you a delivery date if you put an item in the cart and give them an address. could be worth it to pay shipping to avoid driving 3 hours.

yup I love supplyhouse.com - they have a warehouse a few miles from me and items come the next day. I actually ended up finding a watts relief valve in a local hardware store today since Lowes cancelled my online order of it so I didnt end up driving to get it.

So... I installed the valve - works as expected, tested it. I filled the boiler and it seemed that the regulator kept letting water in even after i got to just under 20psi ... so i shut off the water feed and drained a bit of the water to get it to around 10psi. I started up the boiler and ran it for a few minutes, heat started to circulate to all the baseboards as expected, no weird noises or anything just a bit of slight knocks inside the boiler, which I'm guessing is from newly aerated water being boiled?

The one thing that I am not understanding is after a few minutes of operation I did not see the pressure on the gauge move from around 10 psi... so i shut off the boiler since i was not sure why ....

Should I let it run for a while longer? the baseboards are warm. I tried disconnecting the gauge and it reset to 0, reconnected it and turned on the drain and still around 10 psi just as it was when cold... The drain valve is open, zone valves are open, both new autovents are open and no air coming out of them (air did come out in the beginning when i filled though). Could the gauge not be accurate? i can probably test it out on my outside faucet to see what it registers there for fun. It is a cheapo 10$ 200psi gauge.. but it did go above 10psi when i was filling the boiler...

thanks again for any thoughts and advice.

mattmia2

You may still have some air in the system. Did you get water out of the relief valve/the vent on the boiler? What about the one on the air scoop? You will probably be getting air out of it for a while because your air elimination isn't great.

You might want to se what others think because i don't entirely understand what is happening. Your system volume is small so the pressure change will be small, maybe the gauge you have doesn't have enough precision to see it. You can make some marks on a piece of tape on the face that line up with the needle and 2 markings in the gauge and that will let you see small movements of the needle.

genericnj

So I waited for it to cool and added a tad more water to bring it to around 15 psi. Then I ran it for a good hour and observed the pressure. It gets to around 20psi now after running for a while and drops back to around 15 when cool. I think that is pretty good for the operation so I'm going to leave it as is.

Yes I did lift the relief valve until i got water squirting out of it. For some time the vent on top of the expansion tank also fizzed some air out, now it seems most air is out and everything seems to be pretty happy - including me since I have heat.

HUGE HUGE HUGE thank you Matt and everyone who helped me on this little journey fixing this system. It was not something I am used to doing so all the answers to my newbie questions were very appreciated! At some point in the future I will replace the gauge on the boiler since the gauge still shows 70F and 10psi no matter what setting so it is definitely shot, but for now I think I will just let it run and give me warm heat through the winter while observing via the temporary gauge. All in all, am very happy with the outcome of the pump replacement. By the way, I did test the old pump by plugging it into a power cable, the cartidge was not jammed, but would not spin when powered and just like when mounted the pump would get hot quickly.

The new pump seems to operate around 175-180F, while the old one would get over 200F while not pumping. The only thing I have left is to connect pipes to the relief valve to route water around the boiler like it was before.

Again Thank you!!!!

mattmia2 said:

You may still have some air in the system. Did you get water out of the relief valve/the vent on the boiler? What about the one on the air scoop? You will probably be getting air out of it for a while because your air elimination isn't great.

You might want to se what others think because i don't entirely understand what is happening. Your system volume is small so the pressure change will be small, maybe the gauge you have doesn't have enough precision to see it. You can make some marks on a piece of tape on the face that line up with the needle and 2 markings in the gauge and that will let you see small movements of the needle.

genericnj

OMG this morning i woke up and floor around boiler is wet and pressure is back down to 0
The boiler wasnt running at all at night .... could it be that it is cracked? I looked at all fittings i worked on and not a drop from them, it looks to be coming from the bottom of the boiler

genericnj

Found the leak - it is not cracked boiler thankfully - but it is the backflow preventer on the feed line that is steadily dripping water behind the boiler .... that thing is in the cornermost area of the closet ...

mattmia2

I think it is doing its job because the prv isn't holding. It is keeping the waterthat is leaking back out of the prv from flowing toward the potable water by spilling it out of the vent between the check valves.

I would replace both the prv and the backflow preventer and put it someplace more accessible. It might be easier to do it in pex.

genericnj

the prv is right below the pump i just replaced right near the floor, i would have to remove the pump to get to it the backflow preventer seems to leak even when I feed the water too... i may be able to replace the backflow preventer, but im not sure if i can get to the prv ... does the prv hold water from going backwards though? I thought it didnt do that, only reduced the pressure to 12 and so once 12psi was reached in the boiler no more water would go forward into boiler since it would hold at that pressure, but wouldnt care if water moves in opposite direction? i may be way off... I may try to replace it in place, if that fails then I will cut the pipes and move it higher using pex where it will be more accessible for future. I was so happy last night having a working boiler and no more issues and this morning woke up to a puddle of water... not fun

genericnj

Had an idea - what if I cut out the existing backflow prevnter and relocated it higher and put a new pressure reducing valve right below it and then left the old one in place but with the latch in open position all the time?

Red circle is where current backflow preventer is - note difficult to access area.
Green circle is where i could move it to and put a prv under it. -- thoughts ?

genericnj

I wanted to update everyone on the project.

I replaced the backflow preventer and installed a new prv right after it, with the old one still installed after that, but left in open position.

I filled the system and was seeing over 20 psi being pumped in - well turned out my test gauge was faulty, because when I picked up a cheapo 10$ watts one at home depot, it showed exactly 15 psi as the new prv is factory set to.

I've let the system run for a few days now and all is good. I have the auto feed off and have been monitoring pressure. It is sitting right around 12psi cold now that the air got purged over last couple days. Heat is going to both zones no problems.

There is only one thing that is bugging me a little.. When I firtst tested the system at very low pressure (since the gauge was lying to me, i was putting probably around 8psi in and the pump was completely silent. Now at 12psi it seems the pump makes more of a hum that i hear on both floors and at the pump itself i hear a very mild slightly grindy sound that I did not hear when I was testing earlier. The hum is the same as the old pump used to make so I'm guessing that is normal, I did like it completely silent when I first tested though... The other thing is that when the downstairs heat is on and the upstairs is off, some water gets sent upstairs too because the upstairs baseboards get slightly warm - this DID happen in the past too, except when I tested the system with the new pump and the 8psi (that again I thought was 12psi but gauge was off by around 5psi). Would it be bad for the system to run it at lower than 12psi?

Thanks all again - here are some pics of all the things I ended up replacing - before everyone jumps on me, yes I will be putting on a drain pipe on the backflow preventer and also on the pressure relief valve that will go to the floor - i am just making sure there are no leaks or other problems before i put all those on...