Taco 007 O-ring failures

Dave Mundee

Taco says there is an incompatibility with the glycol that's in the system and the EPDM O-rings are swelling. It's Hercules CryoTek propylene glycol that's made for water boilers. And the Taco docs say the circulator is compatible with glycol. Sounds like it isn't...I sure wish I had know that, I would never have to gone to the expense and aggravation of glycol. This all doesn't make sense. These two products should work together. Taco wants me to flush the system with TSP and go back to water. Can I use a commercially vaialable boiler cleaner like the Hercules "Boiler Cleaner" in the quart bottle?

Dave Mundee

Taco 007 O-ring failures

What would cause the o-ring that seals the cartridge housing to the pump body to fail and wind up inside the impellor cavity? Of course once that happens it leaks everywhere. I had one do that a month ago and I dismissed it as a fluke but I had a second one do the same thing yesterday on the same boiler. What a mess. I put in a new circulator but is this a manufacturing defect or what is causing this? I've never heard of it. I have 5 ciculators and 2 have done this a week after start up. Should I be concerned about the other 3?

Gene_3

sounds weird

anti freeze or other additives in system maybe, I have never seen that, and I have reused the O rings on occasion.

contact Taco, I'm sure they would help

Al Corelli_2

New one here.

Never had any problem with a 007, or any Taco pump.

Perhaps there is some petroleum product in the heating system that is attacking the O-ring.

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Gene_3

ugh

did they say if non toxic RV anti freeze would be the alternative??

I'd say use the TSP

Ken_40

Don't forget to

purge ALL the glycol out first with CLEAN water; THEN add the TSP, fire the boiler, circulating every zone totally with warm water; THEN drain that and rinse with clean water: THEN refill with water, or a compatible product; THEN ffire the boiler and bleed all te air by getting the water and all zones to 160F for a few minutes (180 out, 160 back).

Dave Mundee

How much TSP for how long

TSP is ususally a powder right? Do I disolve some in water and pump it in? How much should I use? Total system capacity is about 25 gallons. How long do you leave the TSP solution circulating? Do you leave it to work for a few days or just long enough to circulate and then flush right out? Is the TSP as good or better than the bottle of boiler cleaner?

Ken_40

Yes.

It comes from small "crystals" to almost a garnular powder.

Since stuff is almost harmless, AFTER YOU FLUSH AND RINSE THE GLYCOL out, mix up a rounded cup of TSP and mix it with ~3 gallons of the hottest water you can get in a 4-5 gallon pail and leave enough room in the system to accept it; or, pump it in one end and let the clear water come out the other until the mostly dissolved TSP solution is injected. Small traces of undisolved TSP is typical. Get at least 90% of the TSP in there.

Bleed the air as usual so you know you have full circulation. Fire the boiler. Let it go to whataver the limit temp is (180F?), making sure all zones are thoroughly washed. Let it run for at least an hour at limit setting. If you leave it in for a day, it will hurt nothing.

Then drain all the TSP and crud out. Power rinse the entire system with fresh, clean water until pure. If small trace amounts of TSP are left in the system, that's okay. TSP is mildly alkaline, that's a good thing. When you have all the TSP rinsed out, inject whatever you are going to inject. Unless the threat of frozen pipes is an issue, it's tough to beat just straight, plain H2O.

MAKE SURE YOU BLEED THE AIR OUT!

kevin coppinger_4

before you ...

do the tsp thing why not call George @ Rhomar water conditioning...this is their thing...1-800-543-5975.
www.rhomarwater.com.

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Henry_13

different o-ring?

Maybe getting a different o-ring is easier than draining, flushing, filling. O-rings can be had in just about any size and any material - some of which are compatible with glycol. Buna-N is probably a good choice. MSC industrial supply has them if you can get the inside or outside diameter and the thickness.

Just a thought...

http://www1.mscdirect.com/CGI/N2DRVSH?PMSECT=1926

Gary Jansen_2

Taco said?

Are you sure someone from Taco said you had a compatability issue, or was it a wholesaler or someone "speaking" for Taco. As a former contractor with literally HUNDREDS of Taco wet rotor pumps installed, and now as a rep overseeing thousands of Taco pumps installed in our area, I have never has an issue with Taco O rings and glycol. Noble and Cyrotek are the dominant antifreezes in our area. Taco's seals are compatable with all glycols that I am aware of. I believe you have some other issue in your system. Draw off a water sample and have it analysed.

Dave Mundee

Taco 007 O-ring failure

Yes, it was right from Taco support. He claims the EPDM O-rings were affected by the presence of some kind of hydrocarbons in the system (oil etc.) I don't know where that would come from. It's a three-year-old system and I pumped in Cryotek right from the 5-gal pails. He claims the ring swelled and became slimy. When the ring gets bigger it eventually pushes itself out of the rabbet in the casting and into the chamber where the impellor is. How would I get any oils in the system? I don't know if it's relevant but it's a Peerless WBV-04 cast iron 4-section water boiler.

Ken_40

Did you remember to....

Clean the entire system BEFORE putting the Cryotec in?

If not, the cutting oils all boiler makers use to cut threads, pipe dope used to seal joints and flux used to solder any copperwork, and the fill water "purety" - may have become a chemical "soup"! Adding Crytec, may have made a "soup" that o-rings cannot tolerate. Especially at high temperatures when all chemical activity becomes accelerated.

Most pipe dopes contain oils. Most old system contain "junk" (the highly technical word for dormant - and to use the crude and vernacular word, "crap" - that has not been disturbed, nor should it ever be - until a new boiler is installed, and that coats and lines every inch of pipe and emitters within the system). The soup created may have loosened all that "junk" - which in turn was unfriendly to the o-rings? The flux, "junk," dope, and oils create a compound scientifically equal to "junk" known as "mung."

The cardinal rule being: Only add Cryotec to clean water; never with either "mung" OR "junk".

Dave Mundee

Taco 007 O-ring failure

It was an entirely new system when the glycol was pumped in. Cast iron boiler and all copper zones with fin tube baseboard. I did not clean the system beforehand though. I did use Rectorseal dope on the black iron near-boiler piping. Of course the rest is sweat.

Ken_40

Ooooh...

HWBB, all soldered, flux city; plus, Rectorseal, an oil based pipe-dope; plus, the Peerless, factory threads cut with coolant/oil; plus, oils used to extrude HWBB copper internally; plus Cryotec...

Heat + flux + cutting oils + oil-based dope + drawn-copper HWBB lube + Cryotec = "chemical soup" resulting in: TACO o-ring swelling.

Of course I cannot KNOW this. Just a very educated guess.

Dave Mundee

Taco 007 O-ring failure

It must not take much oil to affect the seals. It's in 25 or 30 gallons of solution. And is it pretty likely that the TSP clean and flush will remedy this now?

Ken_40

Dave,

Again, I'm only surmising. You've witnessed the o-ring and know how much flux (which is a strong acid most times) you used, as well as what the boiler block thrads looked, before you plugged or piped 'em.

And yes. TSP will with certainty, clean the system.

I urge you to observe the color and content of the TSP as it comes out of your hose - when you dump it. I suspect you will be AMAZED! I suspect you will also be amazed at the stink of draining what's in there right now! Chemical Soup is NOT MMMmmm-good (;-o) The scent will also provide feedback.

We love to hear about both times; the draining first, the water "look" when you dump or purge the TSP.

Please stay in touch.

Dave Mundee

Taco 007 O-ring failure

Last weekend when I replaced the circulator that had leaked, I drained all the glycol out of the system and replaced it with water. There was no smell and the glycol looked very clean as it came out. I never saw any black water or anything alarming.

Dave

Ken_40

Mmm...

I'm am mildly surprised, but not that much. Whe you state you drained it, did you mean merely open the boiler drain cock, and vented someway, or did you "power flush" the entire system - making sure ALL traces of glycol were "chased" out? Not that it makes that difference now, but the flux and oils I mentioned, have an affinity to cling, if not in solution. Suggesting the chemistry involved, may be different than the solids from which they emminate?

Do the TSP treatment, get the water up to 180 for an hour or two through anything connected to the system and dump it; THEN POWER RINSE IT.

Fill with clean water and the correct concentration of Cryotec, if still required, and rest easy. You've done all you can, and done it right!

Joe Mattiello

o-rings

The consensus is, something in the system is causing the o-rings to swell. Taco uses EPDM elastomer o-rings which is common in the HVAC industry, because of its resiliency to hot water. However, reiterating from my previous correspondence, sometimes there is something in the water that is not compatible with the EPDM, as Ken mentions in his thread. Normal glycol solutions do not impinge on EPDM elastomer o-rings.
Certainly, the o-rings used on the taco pumps are compatible with glycols, which are commonly used throughout the industry. There are thousands, and thousands of these pumps out there, problematic free, working hard for the customer. Without dwelling on this any longer, I recommend cleaning the system with TSP as I recommended, have the water tested, and continue using Taco pumps. The O-rings that swelled I will replace for you at no charge.

Dave Mundee

Flush

I drained the entire system of glycol (all zones open) out through the boiler drain and then ran lots of clean water through all the zones one at a time repeatedly to purge the air and make sure only clean water was coming out. Admittedly the cold water I flushed through it isn't going to carry much oil out with it like hot water would. When I clean it is it OK to drain the TSP solution out while it's hot or should I wait for the system to cool down to 100 degreees or so? I won't put cold water back in until the mass has cooled down nearer to ambient temp. I don't want to crack anything.

Ken_40

I'd dump it

and purge it when still warm.

Don't worry about cracking anything! Think about what happens 10 times a day anyhow! Zone one calls. The boiler bounces off limit, water temps at max. Zone two calls, water at limit temp surges out while ambient zone two water screams back! Can you say delta tee of over 100F degrees? This happens many times a day!

You may want to flush the hot TSP and attendant "soup" under pressure via purgeing anyhow? Why not? Just check the odor and color/look of the dumping system water. Don't also forget the boiler block itself! Most times we have a drain on one end of the piping, the fill on the other and the boiler "valved out"!

You're doing fine. Easy does it. Common sense will be your guide.