Radiant floor heat problem

[gayler]

I have a problem. The company that put my system in used automotive type antifreeze. This would not be a problem, but our water is extremly hard. The system works very well when it works but the scale build up will cause coolant not to flow at times. Could I add scale defense or another simular product as I do to my hot tub and swimming pool to help out? Without it I plug the filters in both very quickly.If I need to drain the system and use RV antifreeze what can I flush the system with to clean it out? With RV antifreeze what concentration do I need? If adding water to it with RV antifreeze Should I use distilled water? Sorry for so many questions and thanks in advance for all help!

 

[mypov]

I am not sure what product you could use to descale the build up - but I'm sure if you searched google for an answer regarding products that descale mineral build up would serve you well - something that comes to mind is CLR, but I don't know if that would be the best product....

While reading your post the immediate thought that came to mind was using distilled water should've been the FIRST thing the company resorted to when filling your boiler system. Glycol is the stuff to use for these things, but again I am surprised to hear the installation company did not use distilled water in the first place. Should you not clean your system I do see many problems to come in the future.

 

[Fastback]

How many gallons does the system hold? If it is not a huge amount I would consider draining it and filling it with RV antifreeze.

 

[gayler]

I'm very dissapointed with the company that did the install. This system uses a 50gal water heater. I actualy plumbed it in because the company wanted like another 1000 dollars to finish the system. They gave me a diagram and I plumbed it acording to the diagram. The first night it ran it blew out ten gal of antifreeze on my floor. I called them and they said to trim a couple of inchs off the dip tube on the cold water inlet of the heater. After trimming it several times I finally took it out and never had that problem again. This system also has no air scoop, I'm told this is not correct also.

 

[gayler]

How many gallons does the system hold? If it is not a huge amount I would consider draining it and filling it with RV antifreeze.

The heater holds fifty gal plus what ever is in the tubing. The garage is 30x40. I will drain, flush and refill if I have to but money is tight.

 

[Fastback]

Well, most pro's will tell you to use the specific stuff for radiant, but I looked at the ingredients and could not see much difference between the RV antifreeze and the standard propylene glycol that you get in 5 gallon buckets for more money. Right now is the time to buy RV antifreeze in bulk, check big box hardware and run it straight with no dilution.

Did you need to strap the heater elements together or are you hitting the delta you want with the heater unmodified?

Also, while you have it apart put an air scoop or spirovent at the high point of the system but before the pump, you want the pump to siphon fluid past the separator, not push it past.

 

[tdkkart]

I'm very dissapointed with the company that did the install. This system uses a 50gal water heater. I actualy plumbed it in because the company wanted like another 1000 dollars to finish the system. They gave me a diagram and I plumbed it acording to the diagram. The first night it ran it blew out ten gal of antifreeze on my floor. I called them and they said to trim a couple of inchs off the dip tube on the cold water inlet of the heater. After trimming it several times I finally took it out and never had that problem again. This system also has no air scoop, I'm told this is not correct also.

GASP!!! Professionals screwed up your radiant system?? I don't understand, I wonder how BadgerBoiler and a couple other people will explain this??

Anyway, there's no reason you cannot use RV antifreeze. I would use it in as low a concentration as you feel comfortable with in your climate. Ideally plain water would give you the best heat transfer efficiency, but if you're like me, I'd rather not have to worry about my system freezing after a massive ice storm knocks out our power for several days.

Distilled water, if you can get sufficient quantities of it would, be ideal. Otherwise any anti-lime product should at least help, the heat being the biggest issue that'll draw the minerals out of the water and make a mess of things.

 

[gayler]

Well, most pro's will tell you to use the specific stuff for radiant, but I looked at the ingredients and could not see much difference between the RV antifreeze and the standard propylene glycol that you get in 5 gallon buckets for more money. Right now is the time to buy RV antifreeze in bulk, check big box hardware and run it straight with no dilution.

Did you need to strap the heater elements together or are you hitting the delta you want with the heater unmodified?

Also, while you have it apart put an air scoop or spirovent at the high point of the system but before the pump, you want the pump to siphon fluid past the separator, not push it past.

Thanks for the reply! What do you mean about strap the heater elements together? This uses a 50gal natural gas water heater.

 

[gayler]

GASP!!! Professionals screwed up your radiant system?? I don't understand, I wonder how BadgerBoiler and a couple other people will explain this??

Anyway, there's no reason you cannot use RV antifreeze. I would use it in as low a concentration as you feel comfortable with in your climate. Ideally plain water would give you the best heat transfer efficiency, but if you're like me, I'd rather not have to worry about my system freezing after a massive ice storm knocks out our power for several days.

Distilled water, if you can get sufficient quantities of it would, be ideal. Otherwise any anti-lime product should at least help, the heat being the biggest issue that'll draw the minerals out of the water and make a mess of things.

Thanks! What concentration do you think would be OK? It doesn't get much below 0 degrees here. Does reverse osmosis take minerals out also or just distilling?

 

[tdkkart]

Thanks! What concentration do you think would be OK? It doesn't get much below 0 degrees here. Does reverse osmosis take minerals out also or just distilling?

Check the container label or manufacturer for concentrations, some is meant to be mixed, some is run full strength. Also consider that the system is under pressure which changes the requirements.

I don't know enough about reverse osmosis to comment. We use distilled water in all of our water cooled machines at work(PC board milling and drilling equipment), using the distilled water allows us to avoid scale and buildup issues without using any additives. We have our own distiller.

 

[Fastback]

Thanks for the reply! What do you mean about strap the heater elements together? This uses a 50gal natural gas water heater.

Sorry, I should have guessed that. For some reason I was thinking electric.

 

[gayler]

Well I got the tank drained and four of the five curcuits drained by isolating the heater tank and using compressed air to blow through each curcuit. The last one is plugged! I got it moving once but it took a lot of pressure to get it moving. I didn't feel comfortable using any more pressure so I stopped. I think I'll try filling that curcuit with vinegar and see if it will disolve it. If I get cleared I will fill the system with water and two gal of Muratic acid and let it pump through for about thirty minutes and then flush. Will a concentration of 25 to 1 be too strong? Will it be to acidic to drain in a gravel driveway?

 

[anthony666]

it's a very slim chance that a stone got into your tube, more likely that the pipe kinked during construction .. neither one will clear chemically

most likely scenario is you just cant develop enough volume of air to push the water/antifreeze mixture out

hook up a garden hose to that loop and flush it out that way

 

[gayler]

it's a very slim chance that a stone got into your tube, more likely that the pipe kinked during construction .. neither one will clear chemically

most likely scenario is you just cant develop enough volume of air to push the water/antifreeze mixture out

hook up a garden hose to that loop and flush it out that way

Can't be a small sone. It's a closed system. Tubing is not kinked beacause it orinaly worked. This system was put in about ten years ago. My shop air compressor puts out plenty of volume and pressure, I just wasn't comfortable putting 125psi into a system that normaly runs about twenty psi.

 

[anthony666]

Can't be a small sone. It's a closed system. Tubing is not kinked beacause it orinaly worked. This system was put in about ten years ago. My shop air compressor puts out plenty of volume and pressure, I just wasn't comfortable putting 125psi into a system that normaly runs about twenty psi.

brother you'd be surprised about the stuff that get's into pex pipe during the construction phase despite due diligence on your part .. stones from gravel work are pretty common in the grand scheme

ive pulled cigarette butts, screws, pebbles, wasp carcasses, baby mice, pounds of sand and all kinds of things out of systems that have worked fine for years

i was just stating that kinking or mechanical blockage would be the reasons, bar freezing, for not getting the water out .. i stand by my statement that you simply can't push all the water out of some loops with air pressure

please just trust me flush it out with plain water

 

[gayler]

Well I still have one loop that is plugged. I hooked up a garden hose to one manifold and another hose to the other manifold to drain in the alley. opened just the valve on the plugged loop.I left water pressure on it for about ten hours and still no flow. I'm thinking I will put some vinigar in to see if it will disolve the scale that is plugging it. I have used it many times to clean off the chlorine generater for my pool.

 

[tdkkart]

Well I still have one loop that is plugged. I hooked up a garden hose to one manifold and another hose to the other manifold to drain in the alley. opened just the valve on the plugged loop.I left water pressure on it for about ten hours and still no flow. I'm thinking I will put some vinigar in to see if it will disolve the scale that is plugging it. I have used it many times to clean off the chlorine generater for my pool.

I have a really hard time believing you have scale buildup inside plastic tubing. The first place I would be looking is in your manifold valves

 

[Sureshot]

I had mine plug off initially as well. had to use air pressure alternating from both sides and got it going. Filled veything with water and blew down again. Did it several times until everything was coming back clean then blew it down and added 50/50 glycol and distilled water from an industrial supplier. No problems in the ten years since.

 

[sneezer41]

what type of tubing was used?

A closed system should not have a problem with scale, as new water does not flow thru it as it does in plumbing. If non barrier tubing was used, it is probable that it is not scale but rust from your water heater, and any ferrous parts in the system. Cold pex oughta hold a ton o pressure.

 

[Fastback]

Do you have an electrical fishtape? You could bend the end into a small loop so it will not damage the line and try to push the obstruction a little?

 

[rlitman]

Do you have an electrical fishtape? You could bend the end into a small loop so it will not damage the line and try to push the obstruction a little?

That'll work to a degree, but after you've passed about 270 degrees worth of bends, that tape probably won't go much further. Radiant tubing goes up and back a bunch of times. Unless it's clogged right near the end, this isn't the answer.

 

[Milton Shaw]

Have you tried reverse flushing the blocked line. Ditto on the electrical fish tape. Use as much pressure as you have to to get it cleared out. Its useless now clogged up, can't be any more useless if it blows under pressure. But its unlikely it will blow as its encased in concrete. Is it possible someone drilled into it and put an anchor for something in the floor and blocked the tube. Its most likely a kink somewhere that has trapped scale, reverse flushing should take it out where adding pressure from flow direction will only make it clog worse.

 

[anthony666]

make sure it didn't get that loop turned off at the manifold

 

[Fastback]

That'll work to a degree, but after you've passed about 270 degrees worth of bends, that tape probably won't go much further. Radiant tubing goes up and back a bunch of times. Unless it's clogged right near the end, this isn't the answer.

I figure there is a good chance that a clog would happen at the first or last point of restriction.

 

[gayler]

make sure it didn't get that loop turned off at the manifold

Nope. Loop is not turned off.

 

[gayler]

Have you tried reverse flushing the blocked line. Ditto on the electrical fish tape. Use as much pressure as you have to to get it cleared out. Its useless now clogged up, can't be any more useless if it blows under pressure. But its unlikely it will blow as its encased in concrete. Is it possible someone drilled into it and put an anchor for something in the floor and blocked the tube. Its most likely a kink somewhere that has trapped scale, reverse flushing should take it out where adding pressure from flow direction will only make it clog worse.

Yes I have reverse flushed and no flow. I used compressed air and it will start to flow, but will stop again. This weekend I will cut the crimp clamps and pull the tubing off the manifold to check on both sides of the ball valve. I will also try the fish tape, and compressed air again at full pressure. I suppose worm drive clamps should work where the crimp clamps were, correct? There is also no anchors in the floor.

 

[SwampCat]

Try hooking vacum on it or to it???

 

[gayler]

Ok, so I haven't done any work on the plugged loop yet. I did buy some RV antifreeze.When I got home I read the small print and It says not to dillute it. It also says not to use in boiler systems. Keep in mind I don't have a boiler, just a water heater. It says it protects to -50F. It also says it contains Ethyl Alcohol, Glycol,Denaturants, colorant and water. What would be the dangers of using this in my system?

 

[anthony666]

well for a start ethyl alcohol is highly flammable which is kind of a no brainer about feeding it through a device that is full of flames .. alcohol also dries out seals and o-rings, like the ones in manifolds, pumps, boilers, water heaters, tankless units etc .. it's a solvent, which might be bad to pump through plastic pipes .........

i'd say you could get away with it for a while, maybe even years but it'll shorten the life of your system

you need propylene glycol

 

[pstnbly]

The alcohol will degrade the tubing

 

[anthony666]

let's revisit this whole thing

first .. if you have a scaling problem with your water you need to not use that water .. go to piggily wiggly and get some distilled water

second .. if you have one loop that's plugging up for whatever reason you are piped wrong and you have pressure differential issues .. you need either a primary loop with closely spaced tees or a reverse return

third .. if even AIR can't get through that loop it is plugged .. take the offending pipes off to isolate them .. try full city water pressure first .. if that doesn't work weld a half inch barbed fitting to a blow gun and give her all she's got .. if that doesn't get it moving then the last and most drastic option is chemical, a product like CLR ..

fourth .. steel yourself against the possibility that you're have to break up the floor

dude, post some pictures, there's a bunch of us on here it seems that do this for a living, take advantage of the free professional advice and pictures are worth a thousand words

 

[gayler]

Sorry no pictures, but I pulled the Pex off and the first six inchs was plugged solid with scale. I broke it up with a screw driver and thin blew it out with air. So now I think I will get it flushed real good and drain an d refill with distilled water and the proper antifreeze.