Taco 006 circulator cartridge O-ring too big to reseat???

Jells

I took off the motor and pulled out the check valve to sweat the frame of a new bronze Taco 006 in. When I went to put the O-ring back it was too big! I've done this reassembly a few times before for installs and cartridge replacement, no issues. I could not get it in the seat cut in the bronze. I tried to get it to compress in by gently screwing down the motor housing and only succeeded in destroying the O-ring.



Fortunately I had a spare cartridge with the ring that I could steal, thinking maybe that one was a fluke. Nope, exact same size and problem! Not even close. ???? At this point I'm thinking measure the seat and order a new O-ring from McMaster that will actually fit. Does anyone know anything about this issue? Is there something I'm missing or messing up?

hot_rod

Try a local auto parts store. Most have O-ring kits to build exactly what you need. Same with hydraulic repair, and hose shops.

pedmec

I have had the same problem a bunch of times. i think you really need patience. that's the only way i know. i think they are purposely bigger to hold them in place but its just an educated guess. lot of the first company ceiling units are in terrible locations and almost impossible to replace the oo6 circulators so its worth leaving volute in place. you will get it.

Jells

hot_rod said:

Try a local auto parts store. Most have O-ring kits to build exactly what you need. Same with hydraulic repair, and hose shops.

I guess that's a possibility, but it's bit easier just to order the proper size from McMaster and have it in the afternoon. I've made hot knife o-rings before, but I'm not sure I want to trust it for a circulator pump. 

But I'm still baffled as to how this problem exists. You don't want to have to compress your o-ring into the seat because you risk a loop popping up on the inside where you can't see it even if it looks like the unit has seated properly.

Jells

pedmec said:

I have had the same problem a bunch of times. i think you really need patience. that's the only way i know. i think they are purposely bigger to hold them in place but its just an educated guess. lot of the first company ceiling units are in terrible locations and almost impossible to replace the oo6 circulators so its worth leaving volute in place. you will get it.

I don't know. I'm a pretty patient guy when it comes to this stuff, I'm a professional craftsman even though I am not a full-time heating pro. There is simply no way to have this whole ring sit in the seat by itself. I've just looked at a bunch of videos on YouTube and a lot of them show that people just put the o-ring in and it sits there! One guy struggled but eventually got it to sit. You can see in the picture there is just too much slack to get it to press and sit in there so that you can put on the motor housing.

GW

Wasn’t there a trick where you throw it into the freezer? Maybe I dreamed that

Jells

GW said:

Wasn’t there a trick where you throw it into the freezer? Maybe I dreamed that

Maybe you're remembering the Challenger disaster!

EDIT: bizarrely, a search turns up recs to put it in boiling water to shrink it! Some say it's for rings that have absorbed fuels and solvents, and the heat drives it out. But the virgin ring I have that had been in storage for years is the exact same size as the one in the virgin pump. I might try it, what do I have to lose?

pedmec

chilling it might be the answer. one time i was replacing a flush valve for a one piece kohler toilet. you have to push in and then turn it to lock it in. but the gasket was so hard and the flush made out of plastic that i was afraid to break it. so i said, what the hell and i called kohler to see if they had any tricks and the tech from kohler told me to put the gasket in hot water for a minute to soften it up. did what he said and within seconds i was done. good little trick. flush valve was special order so couldn't afford to break it

Jells

I'm still baffled. I 've tried heat and cold, nope, won't go in. I just don't get it, Taco gave me the spec for the O-ring and it's a standard plain vanilla ring with a OD spec of 2.381" (I bet it's really 60.5mm). The O-rings I have seem to be around 2.395 on my caliper, so a little over spec. The seat measures 2.342 (59.5mm), even more under than the ring is over.  I doubt they screwed up the cutting of the seat.

I'm going to order rings from McMaster, 25 for $8 rather than the absurd $16 for the Taco 2 pack of 2 possible sizes for a pump. I'm also ordering the next size smaller rings, 2.318" which should work fine as the pressure should just set it against the outer rim of the seat.  Something just makes no sense, maybe someday I'll find out...

Dave Carpentier

The spare cartridge that you took the second ring out of.. can you get either/both back into that spare unit ?

Jells

Dave Carpentier said:

The spare cartridge that you took the second ring out of.. can you get either/both back into that spare unit ?

It doesn't sit in the cartridge, that has a face that the housing presses on the o-ring when its in it's seat on the volute.

pedmec

they might have changed companies that make them. had that happen before. not with taco but other companies. all in the effort to save a few bucks.

did they tell you they were standard o-rings? not high tempered o-rings? most high temp equipment I work on require high temperature epdm o-rings or washers.

Jells

pedmec said:

they might have changed companies that make them. had that happen before. not with taco but other companies. all in the effort to save a few bucks.

did they tell you they were standard o-rings? not high tempered o-rings? most high temp equipment I work on require high temperature epdm o-rings or washers.

Weird thing is the rings from the spare cartridges are at least 5, maybe 10 years old! So not from a new supplier.

Taco told me the exact dims and it was EPDM. Found them as a common standard part on McMaster, 9557K173. They have exotic o-rings listed, but these are clearly from a common series. Makes good sense to design to a common spec if you can. These pumps aren't for anything hotter than a hydronic boiler,180F is not what I would consider hi temp, and McM describes them as "Water- and Steam-Resistant EPDM O-Ring". I'll have them tomorrow, one ring or the other should work!

pecmsg

Jells said:

I took off the motor and pulled out the check valve to sweat the frame of a new bronze Taco 006 in. When I went to put the O-ring back it was too big! I've done this reassembly a few times before for installs and cartridge replacement, no issues. I could not get it in the seat cut in the bronze. I tried to get it to compress in by gently screwing down the motor housing and only succeeded in destroying the O-ring. Fortunately I had a spare cartridge with the ring that I could steal, thinking maybe that one was a fluke. Nope, exact same size and problem! Not even close. ???? At this point I'm thinking measure the seat and order a new O-ring from McMaster that will actually fit. Does anyone know anything about this issue? Is there something I'm missing or messing up?

How much was it stretched removing it?

mattmia2

They will swell if they are a marginal material for what fluid they are in, but if you just took this out of the box it should not have swollen. I like to order o-rings from one of the couple o-ring web sites, they have virtually every size and material available so you can pick something that will still be pliable in 20 years and is just a little smaller od so it fits the groove. Make sure the cross section diameter is the same, that is important. Usually you can get it to stay in the groove if your kind of slide it in with a couple thumbs. Maybe the bronze circulators are a little smaller then the CI cirulators but they use the same o-ring.

HVACNUT

Did it get wet? I've had that happen... once.

Joe Mattiello

the o-ring slimy in addition to large? it might have been compromised. Taco does put a couple sizes in with replacment cartridge to capture different rev. Get the exact part number off the tag, and Call Taco tech support at 401-942-8000 and ask for tech support. They can put one or two in an envelope and get it out to you right away. hopefully this helps

Alan (California Radiant) Forbes

I’ve had the same problem more than once. Very frustrating and it makes no sense.  And tech. support says they’ve never heard of the problem before. None of the o-rings they give you with the replacement cartridges work. 

mattmia2

Does it seal to a flat surface or is there a groove on the other side too? If it is flat then there is a lot of variance in the diameter of the groove where it will still be compatible with replacement parts but use a different size o-ring. That application is probably a good candidate for just cut a little section out since it isn't a moving part, it is essentially just a gasket.

hot_rod

mattmia2 said:

Does it seal to a flat surface or is there a groove on the other side too? If it is flat then there is a lot of variance in the diameter of the groove where it will still be compatible with replacement parts but use a different size o-ring. That application is probably a good candidate for just cut a little section out since it isn't a moving part, it is essentially just a gasket.

It is captive on one side only, and I have tried cutting an o-ring in that applications, it will leak!

Might be better served with a flat gasket, like pump flanges use, if the o-ring size is too elusive

jumper

Incorrect O ring will not work for long. In my day a company called Apple offered countless variations. If there isn't too much thermal cycling goretex packing may work.

Jells

jumper said:

Incorrect O ring will not work for long. In my day a company called Apple offered countless variations. If there isn't too much thermal cycling goretex packing may work.

C'mon, if it's the right diameter material only 1/32" under in the ring OD, the water pressure will stretch it the little bit to fit against the outside of its seat and it will work just fine.

Jells

Well, I finally got the McMaster O-rings a day late, they nicely comped me the shipping. And the answer to the riddle is that Taco is getting out of spec Dash #139 O-rings, and has for many years since the one from the spare cartridge is at least 5 years old. The new Parker branded ones that met the spec Taco told me on the phone went right in, snug but with minimal effort.

It's hard to get an accurate dia measurement of a rubber ring without gauge pins, but I set up this shot of them stacked and restrained with steel parallels so you could see the difference in the length of these rings. That extra on the end of the bottom ring is what would not fit into the volute seat! I'd be fascinated to know what trick they use in the Taco assembly room to get that damn ring in!

rich p_4

Hello,
I have run into the same problem. I replaced one 2 days ago and was lucky I had a square face o-ring in my truck that was in a TACO bag with other o rings. Bag was marked006-047RP
I have realized that the ones TACO sells now are not exactly what I need.
I am primarily looking for the O-ring for the bronze 006 circulator.
By chance could you share the ones you have found. As well as where to purchase.
Thanks,
Rich

Jells

rich p_4 said:

Hello, I have run into the same problem. I replaced one 2 days ago and was lucky I had a square face o-ring in my truck that was in a TACO bag with other o rings. Bag was marked006-047RP I have realized that the ones TACO sells now are not exactly what I need. I am primarily looking for the O-ring for the bronze 006 circulator. By chance could you share the ones you have found. As well as where to purchase. Thanks, Rich

Rich, it's all in my post above, the part description and I got them from McMaster-Carr.

rich p_4

Hello Jells,
I looked at McMaster Carr and tried to identify the Dash#139. I am not familiar with their catalog
Do you have more detailed info to help me with the purchase.
I appreciate your time and help!!
Rich

mattmia2

somewhere in the search bar on the left on the o-ring page is a selection for dash numbers. You can also go to web sites that only sell o-rings, they have more selection and more flexibility with quantity than mcmaster-carr.

109A_5

Hello @rich p_4,

If you want to use McMaster-Carr as your vendor, if you are using a phone try a computer, their catalog is very easy.

Go to https://www.mcmaster.com/o-rings/ pick the O ring material you want and then scroll down to the size you want.

Joe Mattiello

hi
there are several generations of Taco 006 pumps, and O-ring diameter has changed because of diferent castings. Taco includes a couple different sizes in repart part kit for this reason. If you take part number off tag, and call Taco tech support at 401-942-8000, ask for tech support, they will provide correct replacement O-ring diameter. let me know how you make out...

Pumpguy

Some words about O rings:

O rings are available in many different elastomer compounds. The elastomers I'm familiar with are Buna-N, Viton, and EPDM.

The temperature ratings for these are: Buna N, 225*F. , Viton, 400*F., and EPDM 300*F. Buna and Viton elastomers are recommended for use with petroleum fluids but EPDM is not.

EPDM elastomers are recommended for use with boiler water treated with Amine based chemicals. On the other hand, Buna and Viton are not recommended for use with Amine treated boiler water.

Based on the temperature rating and Amine resistance, I use EPDM elastomer shaft seals for any application that will see boiler condensate.

I am sure there is a concentration threshold where the Amines begin to affect Buna and Viton, but I have never been able to learn what that threshold concentration is.

Ever heard of Crazy Glue? This product originated as a product called Eastman 910, or so I'm told. Eastman 910 was developed as a product to glue O rings together from bulk stock or for a non-standard size. I've never tried it, but we were taught about this when I worked at the Argonne National Laboratory.

hot_rod

Pumpguy said:

Some words about O rings: O rings are available in many different elastomer compounds. The elastomers I'm familiar with are Buna-N, Viton, and EPDM. The temperature ratings for these are: Buna N, 225*F. , Viton, 400*F., and EPDM 300*F. Buna and Viton elastomers are recommended for use with petroleum fluids but EPDM is not. EPDM elastomers are recommended for use with boiler water treated with Amine based chemicals. On the other hand, Buna and Viton are not recommended for use with Amine treated boiler water. Based on the temperature rating and Amine resistance, I use EPDM elastomer shaft seals for any application that will see boiler condensate. I am sure there is a concentration threshold where the Amines begin to affect Buna and Viton, but I have never been able to learn what that threshold concentration is. Ever heard of Crazy Glue? This product originated as a product called Eastman 910, or so I'm told. Eastman 910 was developed as a product to glue O rings together from bulk stock or for a non-standard size. I've never tried it, but we were taught about this when I worked at the Argonne National Laboratory.

The durometer of a sealing ring is also important for the specific application.
 I think Viega has 2 or 3 different rings for their press fittings, depending on the fluid and temperature.