I need to replace a defective cast iron Taco Water Pressure Reducer and Taco Hy-vent air vent on my 3 zone residential hydronic system, and would appreciate advice.

First, I am wanting to use a 3/4" flexible copper line to connect the water supply to the reducer. It will allow me to remove a defective reducer, if needed and also come in handy when I raise the boiler 22" next spring - to meet city code (in the garage). Is the flexible water line okay?

Second, I am thinking of using a brass Wells reducer instead of the cast iron Taco. Is this a bad idea?

Third, could anyone recommend a really good vent for purging air on the second floor loop? The Taco Hyvent is new, but doesn't seem to purge air at all. I've had the same problem with two of them. I have to manually release the air. It's installed on the second floor zone, near the return to the boiler. Any advice?

Thanks in advance for replies.

 

Seems you've had constant problems with this system for several years now...

I wouldn't use a flex line for the water. When you replace the regulator, install a ball valve ahead of the regulator, far enough back that when the boiler is raised up later, you can just shut that off and run new pipe.

Don't know what a 'wells' reducer is.

If you've got a constant problem with air in the second floor loop, there is likely some repiping that could be done at the boiler to end those problems.

Pictures would help to get some answers, you can set up a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload them there and drop a link here for us to view the pics.

 

"Seems you've had constant problems with this system for several years now..."

Pretty much the whole house. lol... Thanks for advice.

I don't have the digital camera, wife took it out of town, I don't know if the sketch will help.



Link to the Wells (brand) w/p hoping to purchase
Watts 0386421 - Watts - TB1156F 1/2" Bronze High Capacity Feed Water Pressure Regulator
and replace Taco 329-3 - Taco - Taco Cast Iron Pressure Reducing Valve (Sweat)

 

where's the expansion tank?

 

Is it a conventional steel tank, or a bladder type?

And the 'air scoop' ?

You mean WATTS, and yes, that's fine, install with a backflow preventer.

 

I ommitted the steel tank in the drawing. It sits directly over the top of the boiler.

If you look at the return line, the Taco Hy-vent, is screwed in right at the 90 degree where it drops down to the boiler.

The past couple of years, I have been manually feeding a few pounds of water pressure on a daily basis, keeping the system at 15-20lbs, and purging very small amounts of air using a little petcock valve that was installed near the top zone valve, other times unscrewing the cap on the Hy-vent. I'm hoping that the new WP reducer will help alleviate build-up of the air bubbles as well as maintain pressure.

 

Ok, that's fine, but what we want to know is; Where is it connected to the system? The actual way this thing is piped will play a large part in how well the system can eliminate, and keep air out, of the rest of the system.

Alarms are going off here, full blast.

If you are adding water daily, you have a LEAK! SOMEWHERE...

There is no reason, other than a leak, to have to add water to a closed heating system on a daily basis, and what's more, adding that bit of fresh water daily is rusting out your system from the inside.

Fresh water contains Oxygen... keep adding oxygen, and you keep rusting...

Water that has been in the system for a time has the free oxygen driven out of it, and the water becomes inert... no oxygen, no rust.

Do you have radiant heat pipes embedded in concrete?

Changing the type of air vent that you use isn't going to help your problem. The air has to GET TO the vent in order for it to be released.

We really need to see pictures.

 

Wow you guys are on it tonight!!! I was getting ready to enjoy a cigar and bourbon on the patio and call it a night. Thanks again!!

Unfortunately, I have no digital camera until Tuesday, when my wife returns from Texas.

Yeah, the system seems to be losing water. The garage and main floor zones are embedded in concrete. The only place that seems to show any evidence of a possible leak is a small area in the kitchen. The floor is covered in a dark green linoleum and there are clearly red markings bleeding through at the point where two of the loops bend around. However, the system has been steadily holding about 8 pounds pressure since setting idle beginning spring.

Here is a photo of the boiler. A "T" is installed sideways and the tank is installed on a short nipple and elbow running off the side of the T. The drip leg comes off the top of the T.

http://i882.photobucket.com/albums/a...t/scan0002.jpg

 

That cigar and bourbon sounds good right about now!

What might be happening is that with the concrete and everything around the pipe that it's able to hold the 8 PSI and not leak... it's a wild theory, but maybe...

I'm guessing that your home was built probably in the mid-fifties?
Can you tell what kind of pipe is in there?

We'll wait for the pics...

 

The house was built in 1966. The boiler is original.

Pictures by UndertheInfluence_bucket - Photobucket

Got the Watts reducer and plan to install today. But as I said earlier, I want to get the boiler of the floor to meet local 18" code. Any suggestions are welcome.

Thanks again

 

Can a Taco 329 pressure reducer valve be cleaned and re-used?

I seem to be replacing them every 3 to 5 years, and have concluded it's due to a high mineral content in my well water.

I have recently replaced most automatic vents, and don't seem to be needing much additional replacement water this winter.

Replaced 329s have always been tossed as if they're a consumable item.

I'd like to buy one more and then give the current one a CLR or vinegar bath and have it available for next time it gets clogged with mineral deposits.

Is that a stupid idea?

 

No, not a stupid idea... but I don't think any replacement parts are available for their product... Watts on the other hand has repair kits available for their 1156 regulator. B&Gs FB-38 does not have to be disassembled to remove and clean the internal strainer.

Do you think it's minerals? or sediment? on a well system, could be either... think about installing a wye strainer upstream of the reducing valve, might lengthen the life some.

And always... before you replace a valve, flush the incoming line out real well.

I'm on a well here also, and have the same problems... next time I have to replace, I'm gonna add the wye strainer, and get the kind that I can put a hose bib in the flush port of the strainer, and periodically flush the line out.

 

Hello Vermont,
Are you saying that a clogged air vent caused the water pressure to drop? I am curious to know how you discovered that.

I have to say that I am confused by the operation of the hydronic system. The basic function of the components looks like a no-brainer, but trying to troubleshoot air in the lines and water pressure drops is still somewhat of a mystery to me.

I installed a new pressure regulator, which functioned flawlessly for a couple of months at around 12lbs. At least I thought so. When temps dropped to about 5-20 degrees last week, I woke up to a very cold zone one morning (60degree actual w/ T-stat set at 66) and noticed the pressure was a couple of pounds lower than it should have been. I raised the pressure manually to around 15lbs and unscrewed the cap on the Taco Hi-vent to purge a little air. Temperature stayed steady for several days. Then, the last couple days have seen drops in room temperature at night again. I'm guessing air blockages.

It's pretty frustrating having to endlessly tweak this thing and I haven't had good luck with Contractors trying to troubleshoot.

 

No; but the automatic vents played a role in allowing a continual (or periodic) escape of water (steam) and then triggered the automatic fill (Taco329 in my case) to bring in more replacement water until it itself became non-functional because of mineral deposits (I suspect). So then the feed valve needed manual encouragement to replenish water. That's what I do (very carefully now, so as to not add so much that I set off the PRV!) Air bubbles in the baseboard WERE a constant reminder of when there was a call for heat. Today I have no noisy bubbles in the distribution line. I think my circulator "pulls" rather than "pushes" so sometimes a big accumulation of air (ie a bubble) could stop the distribution cold (not to make a pun). But I don't know enough to do more than say I'll think about your problem some more. I only know what I know by having become intimately involved in this system here.
Thank you for understanding my question! I don't think it's sediment. I have a shallow well with a piston pump in the basement.I replaced the water line a few years ago and positioned the intake about 3 feet above the bottom of the well with a foot-valve and a good intake strainer. In the basement, we installed a sediment cartridge filter BEFORE the pump (to protect it) so that very little grit/sediment/or frogs and polliwogs get into the house anymore. Plus the mineral deposits become very hard and cake-like. They are not orangish or turquoise blue like rust of copper.

I have/had an air scoop at a high point in the basement above the boiler . . . . you ought see the amount of mineral deposit crusted on the outside of it. It's almost pure white! I ought to scrape up a sample and take it to a college laboratory to have it analyzed. It must be okay to ingest, people have been drinking water from my spring/well since the 1830s.

I bought this place in the 1980s and didn't even know how to spell plumber at the time; and now some days I pretend to be one. In this area, you have to tend to many household emergencies yourself, as lead times for a professional might be measured in weeks. I've replaced the nozzles; electrodes; oil pump; burner motor; stack controller (when I had one) circulator; the whole burner; and the triple acting aquastat (a few times).

I don't have a current emergency. But I've been thinking about clearing up that Reducing Valve. I wrote yesterday because it was the 6 Year anniversary of my last crisis, of 1/9/2004 when my power went out for 9 hours and the outside temp was at -48°F and I struggled to keep the inside temp above +40°F. I'd like to replace my boiler water with a mixture of propylene glycol to avoid being so concerned that I might experience another freeze-up; but this seemingly continuous water replacement has slowed me down. Maybe, if my elimination of the automatic vents has stopped the inflow of new water (with minerals), I can re-consider that anti-freeze task.

At any rate, thank you both for understanding my question. It certainly isn't fodder for polite cocktail conversation. You have to have become acquainted with some of these issues in order to find them interesting.

I don't want to belabor my welcome here; but I did replace my mechanical aquastat with a Honeywell Electronic L7224U, and I don't see how the settings for high limit, low limit, or the differential are retained in the event of a power failure. I've got a call in to Honeywell's hotline; but it has been a week; so I don't think an answer is forthcoming. The booklet for the L7224U doesn't speak to power outages; and I don't see any kind of battery which would preserve the settings.

I may start a separate thread on the L7224U. I did a search and don't see that it has been the subject of a prior discussion here . . . . yet. Thanks again!

 

Wow, you HAVE done some heavy duty maintenance! I thought it was something special when I replaced a couple of zone valves and was able to troubleshoot and temporarily repair a faulty aquastat.

But in your response I think I'm seeing a confirmation of what I have thought, but seen no mention anywhere else: the heating of the water (or some other unknown force) leads to a small conversion of water to air (vapor bubbles), and, over a period of time, if the air is not purged and replaced with water, then the vapor accumulates and ultimately restricts or completely blocks flow.

I'm suspecting that a better air-vent than a single Taco Hy-vent may correct some of my problems AND that the Hy-vent is not working properly. I've followed Vent instructions to clear a blockage, but have never been able to leave the Vent's cap loose one turn as advised w/o water streaming out. So I am probably getting virtually no air purging at this point.

Thanks for your input.

 

Any Vents that are highly recommended?

Thanks again

 

I'm not knowledgable enough to make recommendations. I'm just an observer. But I can say that I'm slowly moving to not having any automatic vents on my hydronic heating system.

I periodically feel my expansion tank and can tell that it's half filled with hot water, and half filled with air while the boiler is in operation. That seems right.

I have not had my PRV blast open in two years. That seems right. I like PRVs that have never opened. In my environment, it seems that they never fully seat themselves again . . . . probably my minerals again. After one release, they seem to continually "weep".

I've not heard bubbles traveling around in my baseboard convectors for a few years now, and that seems right.

If I had a vent that is my very favorite, it's a certain bleeder valve at the highest point in the baseboard. I have to open it with a screwdriver. In a 1830 house, nothing is level, and a few years ago, I discovered this bleeder vent at the very highest point in the baseboard (after living here over 10 years!). What I did was stop heating for an hour or so, and encourage all of my bubbles to consolidate one place . . . . the corner of the living quarters where the newly discovered bleeder vent was located. I fabricated a special piece of aquarium tubing to fit over the bleeder, and bled off a pint of bubbly (almost carbonated) filthy dirty boiler water (but probably germ free) and some air. Then I let it sit for another hour to rest a little more while I carefully, and manually added an estimated pint or so of "new" water down at the fill valve (which is no longer automatic). When I got that much air out, I knew I was on to something, and I would have repeated the procedure as many times as necessary to rid the system of air. You might want to examine your baseboard at those highest points.

I'm in Real Estate and one of the most common items I see in people's basements are abandoned expansion tanks from both their water and their heating systems. The diaphragms (neoprene I think) just give up the ghost too frequently, OR these tanks are falsely accused of being the source of many problems. I forget if you said you checked yours. All of these little gizmos play a role, and they have to work together in harmony to have a "system". And just like people, one will often point an accusing finger at another.

 

Excellent discussion gents!

Vermont, have you considered water softening equipment? (I know this is off topic, but we are, after all, talking about boiler water!)

Interesting about your 1830 well-spring. Theres one near here that the native Americans highly revered as medicinal spirit water and it is some of the nastiest stuff... IRON! OMG... probly 1000 ppm. Might as well lick an old Chevy Big Block.

more... Ive gotta reboot...

 

Oh, it's been discussed! many times...

Fresh tap water has TONS of air dissolved in it. (Well water perhaps not as much though... but certainly some)

COLD water has a much higher capacity to hold air in solution than does HOT water, so when that air rich fresh water is heated, that air just comes out of solution and forms bubbles, and just as you say, those bubbles will collect at certain points in the system and completely block the flow of water:



Experiment: Draw a glass of cold water from the tap. Let it sit on the counter and warm to room temp... see all them lil bubbles on the side of the glass?

 

Thing about air vents is this... there has to be air UNDER them in order for them to vent that air! Some guys just stick those things all willy-nilly on every pipe they see... and in most cases, it's pointless because no air will ever collect underneath them, and won't be vented.

In general, the best location for an automatic air vent is on top of a device that is designed to 'scrub' the bubbles out of the water flow. There are a few types of these devices... cast iron 'air scoops', 'micro bubble' scrubbers (Spirovent is one), and others...

The only other location that a vent will do any good at all is a high point in the system such as Vermont described.

You _could_ place an auto vent at the location in the diagram in the previous post, but in general it's not a good idea because those devices do have a tendency to leak, as you are well aware. If they are tucked inside a baseboard somewhere, they could well leak for YEARS before the bedroom floor rots out and you wake up in the kitchen.

If yours leaks, replace it, or keep the cap closed most of the time and open it periodically to let air out.

 

One concept that should be understood regarding air removal from a system is that of "Pumping Away". I'm not going to elaborate on that here and now, because there is TONS of info about it out on the 'net. Google the term, and enclose it in quotes. Ignore the porn sites that might come up... or not...

Also, the search function here on the forums will turn up lots of posts regarding same, but you won't get the porn.

If after reading all that stuff you have questions, ask 'em!

 

And I wouldn't bet any beer on it, Beer 4U2 , but there's a very good chance that half of those abandoned tanks are perfectly good... or at least were when they were abandoned.

It's a sad fact that there is precious little real UNDERSTANDING of the physics and mechanics of how hydronic systems actually work. Even (and especially) by the 'so called' pros. Also a sad fact that the expansion tanks are the most neglected part of a system. I firmly believe that if they were added to the list of preventative maintenance items, and PROPERLY maintained ANNUALLY (or at LEAST bi-annually) they would fail far less often. By keeping the proper air charge in them, the bladder will flex far less, and last far longer. Case in point: the tank on my system... over 20 years old and not a dang thing wrong with it... OOOPS! I did it now... I've jinxed it I'm sure.

 

UnderDogBone, the location of that air vent is just as I described... nearly pointless. When water is circulating, any air bubbles are not going to magically find their way into that vent... no, they'll whiz right on by, and unless it's a high spot where air can collect after some period of boiler OFF time, it will do no good.

Also, I'm still convinced that you've got leaking pipes in the slab... are you still adding water daily?

 

Thanks for the humor with which you approach this sometimes mundane subject. I actually like our Spring Water, so a water softener is probably not in the cards for me; but I do used "distilled water" for ironing clothes! For $10.00 or $15.00 I could pump distilled water into the boiler.

I'm thinking about the Propylene Glycol being employed at maybe 50/50 in the baseboard. Using 50/50 Distilled would be okay. As long as I don't have any further air infiltration.

It used to be that the Propylene Glycol would acidify after a while, especially if subjected to high temperatures; and then it would attack your sweat joints. Maybe that problem has been overcome. I also know that some plumbing companies pump propylene glycol into the domestic water system to winterize . . . . where it will over winter, completely dissolve decades worth of mineral deposits . . . . so much so that for me, to obtain a clear sample for a water test, the water has had to run for 24 to 48 hours to then run clear.

Around here I see plenty of people installing water softeners to overcome periodic "Sulphur Water", and then they don't maintain the systems anyway. Once they get used to it, it just smells like some has let gas in their houses all the time.

Now, before I start another thread, does any reader here know if the Honeywell L7224U Electronic Aquastat has the capacity for retaining boiler settings during a power outage? Could it revert to some factory settings? I can quickly reset mine (for the moment) but I'd hate to be an elderly consumer who had to await a plumber's technician to re-set them when the outside temp is -48°F . . . . it would not be good!

By the way, I still have a pressure tank for my Well Pump which does NOT have a diaphragm. And my Boiler used to have an expansion W/O a diaphragm. But it was a simpler world. I'll bet that most air in the system would migrate to the expansion tank. I like your diagram for UnderBone. I think he is on his way to a solution!

 

No, I haven't been manually adding water. I replaced the wp reducer so its done automatically. Not sure why, but it dropped a couple of pounds under the setting last week.

 

That's not good Bone... adding all that fresh water with it's dissolved O2 and minerals is going to destroy that boiler... and you say it's already been this way for years... I'm surprised it's still working! You need to do something about that leak.

By the way... brass/bronze valves supposedly are more resistant to the mineral build-up problem. I don't have any proof of that, just going by what I've read on B&G's website. (there's LOTS of stuff there that's written in plain English... vintage illustrations, but still worth reading if one wanted to be ejumicated about such stuff... check out their 'Literature' links)

Sorry VT, I meant to address this... I'm 99.99% sure that the settings will be retained. They are highly likely to be stored in Non-Volatile Random Access Memory (NVRAM) chips.

 

What can I do? I have no idea how to find a leak when the lines are buried in concrete.

 

Usually the most cost effective thing is to abandon the piping in the floor and install baseboard.

 

Thank you very much. We've had a few brief outages since my installation, and the settings seem to have been left intact; but I see nothing which would indicate that this will always be the case. I'll post again if Honeywell EVER gets back to me with something which says otherwise.

I like the L7224U. I just wish my configuration was such that I could have installed it in a way that I could read the LED digital read-out right side up! Luckily, I don't have to read it continuously standing on my head.

Now I'm going to do a search to see if putting Propylene Glycol in a boiler, and its life expectancy, has been discussed at length here.

Thanks again! I can tell you love this subject matter.

 

Thanks for the explanation, but I am little puzzled about the proper location of the air vent. You provided a diagram showing collection of air at an elbow in an earlier post. If you look at the diagram and photos that I posted earlier, the vent on my system IS in a high spot identical to the photo. Am I missing something here?

 

Hmmm... Surely that's a bit drastic. I was thinking more like, torch the house for insurance money!!!

Kidding aside, I'm curious if there are heat pumps available that would do more than merely prevent the house from turning into an ice cube during the winter. If/when the time comes, maybe I could just use the air conditioning units existing tubing and space pak unit to deliver heat as well as cooling in the summer.

It has been about 10 years, but some friends tried to use a heat pump to warm their relatively new home here in So Illinois and it didn't provide enough heat. Can't remember where, but I have heard that is common.

 

I wonder if a boiler sealant, carefully, and TEMPORARILY, employed, could address the possibility of a leak in the piping that's embedded in the concrete ? I once had a property that I was selling where the Owner was told that the Boiler had a crack in it and water was entering the combustion chamber. He was told to buy a New Boiler. It was probably a continuously leaking air vent - we'll never know. After using the sealant for 2 weeks, and replacing all water (and a few minor components) No Crack. No new Boiler. It's been about 10 years and the mysterious boiler crack has not re-appeared.

Just a thought before you get brought up on arson charges.

Regarding your 2nd Floor Zone, did you look for the bleeder valve up there on the 2nd Floor? That vent in the Garage isn't high enough to help the 2nd Floor.

I'm not a Steam Fitter or Boiler Technician; just a Real Estate Broker who's sold a thousand homes that had various problems before and after the sale (plus many thousands of others that I tried to sell). They're all different.

 

Well... maybe yes, maybe no... as usual, "it depends"...

on how fast the water is moving at that point.

If the velocity of the flow is high enough to keep the air moving along with the water, then no, that bleeder won't help. Chances are that with the location of the pump just below, your flow at that point will be pretty quick, and the bubbles will keep right on moving.

I probably should have elaborated a bit when I posted the pic, and your confusion is justified...

That little graphic applies a bit more to a baseboard run on an upper level, to illustrate the physics of how air can block flow in a baseboard run. The bigger piping close to the boiler won't 'act' the same, and any air near that vent will most likely float back up to the upper reaches when the boiler stops.

 

NJ Trooper, much clearer now. "Air collecting primarily around the baseboards" makes a lot of sense according to the diagram and what you have explained. Those are "THE" highest places in the system by several inches and quite a distance from the circulator. That's where most of the gurgling and sloshing noise emanates from - baseboards on the far side of the house from the boiler, but I've also found major pockets at the bend near the circulator.

Vermont, thanks for the advice concerning the sealant. In response to your question concerning other vents, I checked all of the baseboards thoroughly long ago and there is no vent. Sounds I should consider adding at least one and checking it a couple of times per year for water leaks.

The system runs fantastic right now. Air seems to be the prime enemy, but I haven't purged any for a week and no gurgling or major sloshing.

As for leaks, I'll have to get a better system of air purging installed, do some pinpoint troubleshooting, but sounds like a strong possibility. Hopefully this spring I will have things pretty well sorted out. Maybe I can find a sealing additive.


Thanks again

 

I think most of the guys on here would frown on the use of a boiler sealant, and I'm not sure they would actually get out into the system itself and do the job... they can tend to clog things up too... but, as a last resort I guess it could be justified.

If you do install an automatic variety, I would recommend that you leave the cap screwed down and you wouldn't have to worry about it leaking... then every now and then loosen the cap for a day or two to let the air out and close it again. The alternative would be to use the small 'coin operated' manual vents, but these wouldn't give the luxury of opening the cap and walking away for a few days...

 

I'm a frowner too ! In my business, there are many dwellings that are "sold to the insurance company" for even stranger reasons. But those perpetrators don't bother to broadcast their intentions on the Internet.

Also, most Boiler Sealants (like Liquid Plug) will only solidify in the presence of air. So, IF Bone's leak is encased in waterlogged concrete, it probably won't seal there either. But if it's allowing that much water to escape, then it should also be making itself visible on the floor. Before investing in above floor baseboard, maybe someone could isolate those pipes and perform a pressure test to verify the existence of a leak in the suspect area.

It's too bad that we can't hire a Consultant like Clark Kent who could employ his X-Ray Vision to look into pipes and see all of the mineral deposits and identify the air blockages and also see through floors to observe heating fluid escaping under pressure. For me, being able to look through snow, ice, and earth to see frozen subterranean waterlines would also be helpful. But I'm told Clark Kent is just a Fictional Consultant. So I sometimes just have to pretend that I can visualize what's going on inside these hidden areas.

 

I think I still have the 'X-ray glasses' that I bought from the back pages of a comic book back in the mmphifffftiessss... (muttered uttering to disquise my real age!) I wonder if they still work? I was really disappointed that they didn't work as advertised, but the little girl next door was relieved.

I think in one of the earlier posts Bone had said that there was a 'damp spot' in one section of the house, but I could be dis-remembering the specifics...

I grew up in one of the Levitt 'clone' neighborhoods where all the homes were built with black pipe radiant embedded in the concrete. It took about 40 years for the systems to start failing due to leaks in the slab, but they did, one by one... some of the early failures were repaired by jacking out the concrete to expose and repair the pipes... what a nightmare!... only to find that a month or a year later, it leaked in another spot. Then, the neighborhood all realized the only way to repair was to install baseboards, or forced hot air.

The original construction did not include any insulation around or under the slabs... one nice 'plus' to that was being able to get an early start on the vegetable garden via a heated 'grow frame' nestled next to the foundation... another was never having to shovel snow off the concrete porch stoops... an early snow melt system.

But I digress, WAY off topic!

 

Okay, forget x-ray vision. I found a link that provides interesting information about repairs to slab installed radiant. I pasted in key points, but here's the link if you want to read in its entirity. Any thoughts? Almost sounds too good to be true.
Services | Radiant Heat Leak Detection and Repairs


"Because of the "closed-loop" environment there is absolutely no electrolytic degradation of the copper tubing. The only reason for leakage in a copper radiant panel system is excessive stress. As all concrete slabs crack, if the tube crosses the crack and enough stress or movement is placed on it, over time the tube can anneal and split."

(what about systems that freeze due to power outage?)

"...copper radiant panel homes we repair today have on the average 1-5 leaks."

"With our advanced equipment, we consistently locate the smallest of radiant panel leaks, one drop of water or less -- to the spot the size of a dime, no matter at what depth the tube has been installed."

"most insurance companies will reimburse you for approximately 90% of the cost of the repair as "non-plumbing" work"

"the average cost to locate and repair most radiant panel systems is $1,250.00 - $2,500.00."