Problems with Radiant Floor System

Gordy

Sorry about the extra commas seems my thumb is hot, and the digitizer picks it up as I cross over the comma key to hit space bar.

Mark Eatherton

Remove the flow check out of the pump. Unnecessary restriction, may also be fouled with solder balls etc. I believe it is located in the pumps outlet. Also, glycol is a poor heat transfer fluid. You may be experiencing micro steam flash at the heat exchanger. To eliminate this you need to induce a surfactant to break up the surface film at the heat exchanger fluid interface. The PONPC is the point where the expansion tank is connected to the system. it stands for Point of No (mechanically induced) Pressure Change. The system pump should pump away from the expansion tank, otherwise all kinds of problems will arise.


ME

Gordy

Dawn dish soap....just a little.

smuth10

If I am ready this correctly I think you are saying my current setup is correct and the pump location should not be changed, right?

I woke up this am and checked on the hwh and it was shutoff with error code 991. I posted the error code details below, but it seems like there are too many possibilities to help me anyway. I tried powering it back up and it sounded like a freight train, I thought it was going to come off of the wall. I shut it down. When I got home today I ran the pump for a while to clear out any air. I then let only the circ pump run for a while and I could hear air collecting in the hwh so I ran the pump for a while longer and then did the same with the circ until i could hear no air. I started everything up and it ran great for an hr. No vibration even, but it did not last long. Either the sprio or something else is drawing in air or I am just unable to get everything out for some reason. I am pretty much at a loss. Is it safe to cap off the spiro while it is running to rule that out?

Warning for the “991” error code
・Check for the proper supply gas type.
・Check if there is any blockage in the intake air and/or exhaust. Refer to the “Venting
instructions” in the Installation manual.
・If the water heater is installed as a direct-vent system, check whether there is enough
distance between the intake air terminal and the exhaust terminal. Refer to the “Vent
termination clearances” in the Installation manual.
・Check the total vent length. Refer to the "Venting instructions" in the Installation manual.
・Check the altitude/elevation of area of where the water heater is installed. Refer to the
“High-altitude function” of Section D and change the DIPswitch settings.
・Check if there is grease and/or dirt in the burner (Part #101) and the fan motor
(Part #103), especially if the water heater has been installed in a contaminated area.
・Check if there is dust and lint in the heat exchanger.
・Check the manifold pressure of the water heater.

smuth10

Mark,

Yes, I removed the check valve when I was installing the system. I had read they can be a problem. Early on I was having flow problems, but I removed the filter and I now get a consistent 18-1.9 gpm on the medium setting, which is where I should be.

I am going to try adding dish soap to the system and run it again tonight if I have the chance. I have about 13-14 gallons of solution in my system. Will 1 or 2 oz of soap be enough?

Gordy

1oz in a small system like yours. Run the pump on constant circulation for a day.

Have you checked, and confirmed all possible related issues to the error code?

The air separator should not suck air into the system....unless it's sub atmospheric pressure at that point. You are pumping away from the x tank. But the end of the line is a high pressure drop HX.
This could be enough to drop sub atmospheric by the time it gets through the HX, and back to the air separator. I doubt it.

You have to think like air.... Think about all the places you would like to hang out if you were an air bubble in water inside a pipe. The HX in that type of hwh has a lot of places to trap air. Remember it's designed to run under city, or well pressure. 45psi on up to 60, or more. As I said before air stays in solution better under higher pressure, and flow is much greater under open system pressure.

I understand your need for glycol in the system, but with glycol comes baggage. As been said heat transfer is less, and it's harder to pump.

smuth10

Should I only run the circulator pump or can I leave the hwh on as well?

I have checked everything but the last 3. Not sure how to do those.

Do you think increasing the pressure to 40 psi or so would help?

What's strange is that sometimes it will start up fine and run without noise for an hr or 2 and other times it will sound so bad I have to shut it down. other times the noise isn't too bad and I know it will run ok for a day or so when it sounds like this. Makes me think there is something wrong with the hwh

I put a couple of table spoons of soap in and it is still making the noise, but it looks like you are saying it could take a while to work. What else can I do at this point to get rid of the air? You guys do this stuff for a living and I am sure you have installed a closed system with glycol before. What would you do at this pint if you were me?

Gordy

Just run the circulator get the suds in the system mixed. Burp the air sep once in a while.

I did not ask but is the x tank charged to the system psi? Did you check the tank pressure with it isolated from the system?

Gordy

Your only moving 1.9 gpm. Divided by 4 loops less than 1/2 gpm per loop. So not a lot of velocity there to move air quickly around the system.

smuth10

How do you burp the spiro? Thought it did this by itself. Maybe that is the problem.

I was thinking the Wayne pump would remove the air with its velocity, no?

I did not check the psi of the expansion tank, but the manual said it is charged to 12psi which is approx what my system is running at. I have tried raising and lower the system pressure and neither has helped. the x tank should only have air in it, correct?

At this point Gordy, I am ready to fly you to Michigan and pay you large sums of money to fix this. This shop is my career and if it is too cold in there I cannot work and it is bad for all of my machines and wood. I need to get this working

Gordy

Patience........

Gordy

The spiro vent has the capacity to trap air closed. Just open it to burp the air out every so often then close it. You may have to add more fluid as air is removed depending on how much is still trapped.

You should eventually get less, and less air to the point you get none. May take a while.

At least if you close the vent cap you can eliminate that as a possibility of sucking air into the system.

Jamie Hall

The expansion tank should have some water in it and some air. If it's all air you will find that air might get from it into the system. Do you know if it is the sort with a diaphragm or bladder? They have been known to fail before now.

Mark Eatherton

Gordy, that Spiro requires a threaded cap or ball vale to close it off. Smuth, in going back to the picture you posted, I see what appears to be two automatic air vents connected to the S&R manifold. If that is correct, close both of those off. It is possible that you are sucking air in through the return manifolds air vent. The pump is not in the PERFECT location, but it should still work.

What percentage of glycol did you induce into the system, and how exactly did you guarantee proper percentage. Anything greater than 30% is unnecessary. Anything less than 30% won't contain enough corrosion inhibitors, and corrosion will result. You could be making your own air by boiling the glycol.

In looking at the piping arrangement, I can't see a good way to be able to use a charging pumping to allow you to force purge the system, but then again, my eyes are getting old, and perspective is not perfect.

As has been noted, it is very important to properly check the air charge of the expansion tank with ZERO pressure on the water side. Based on the board that is holding the expansion tank up, that could be a difficult task, but you will need it accessible moving forward anyway, so might as well check it now.

If the tank is not properly charged, and the diaphragm is not working as it should, all kinds of strange things can happen.

Increasing the operating pressure is OK, but shouldn't really be necessary. Typical fill pressure is 12 PSI in your slab on grade application.

When you are force purging, you want to flow no more than 2 circuits at a time, rotating opening and closing from one side to the other. As you are force purging, I assume you are pumping back into a 5 gallon bucket. Keep the end of the hose immersed, and keep running until no air bubbles are rising up from the hose end. If you keep getting air, something is not right, and it is possible that you are sucking air in from one of those vents on the manifolds. Once done, close the return going into the bucket, and charge the system up to around 15 to 18 PSI if you can. If your pump doesn't have enough cajones, you may have to "top off" the system with city water pressure, but be careful not to send in too much water or dilution may cause issues with the glycnoids.

Another thing you might try is to stretch a ballon over the Spirovents outlet and see if it becomes inflated. If it does, your Spirovent is pregnant.... (JUST kidding) An inflating ballon is an indication of incomplete purging.

Also, as previously noted, glycol puts down a film on the heat exchanger that will cause all sorts of noise issues (boiling sounds, howling, moaning etc) The use of TSP will break this film up and quiet down the system as a whole, but would suggest you get everything else corrected before resorting to that.

Persistence is a virtue, patience is a necessity.

I can check and see f we have any members in your near vicinity tomorrow. Not sure where Steve Ebels is, but if he's close, he's a sharp hydronics cookie.

ME

smuth10

Jamie,

This is the tank I purchased
http://www.supplyhouse.com/Amtrol-101-1-15-Extrol-Expansion-Tank-2-Gallon-Volume-2556000-p

smuth10

Mark,

First, let me thank you, Gordy and the others that have taken the time to help me trouble shoot this. I can't thank you guys enough, truly.

Right now I have the hwh shutoff and I am letting the circ run the solution with 1oz soap through the evening.

Mark, let me try to answer your questions the best I can.

I have been using a 1\2" cap to close the spiro when I run the Wayne pump for filling\air purging

Both of the air valves on the manifolds have always been closed and were on there when I pressure tested the lines to 100 psi for the inspection.

I bought a 5 gal bucket of 100% propylene glycol and mixed in 10 gallons of water into a garbage can and then used this solution to pump into the system. I will take a pic tomorrow of the glycol I purchased and post here.

12 psi is what I started out with, but the manufacturer told me to keep raising it 5 psi at a time until it stopped to keep the glycol from boiling. I went to 30+ and it never stopped.

That is the procedure I have been using except I have been doing one zone at a time. I was getting recurring air in the system before I capped off the sprio vent when filling the system. I am not getting any air coming out now after just 5-10 minutes. My Wayne PC4 pump has no problem bringing the pressure up to whatever I need.

Great idea, I will do this tomorrow. Now I just need to find a balloon.

That would be great. I have pretty much exhausted my abilities and as I said before, I would gladly pay someone to fix this for me.

Mark Eatherton

Creating some back pressure on the return hose will keep the Spiro air vent from acting like a vacuum breaker, which is what you are dealing with. So, it sounds like you went in at 50% glycol solution, correct? That stuff is VERY viscous, and can create a lot of the problems you are dealing with as it pertains to boiling, slow flow etc. There are two ratings for glycol. One for burst and one for freeze. I always use the freeze, not the burst number.

I typically don't use antifreeze unless one of three conditions is present. One, possible loss of power or fuel (think remote mountain home that is not continuously occupied, and could lose fuel or heat, un-noticed)

Two: Snowmelt (Duh...)

Three: Structural preclusion and possibility of pipes being exposed to freezing conditions.

If yours is not one of these three, I wouldn't have induced glycol into the system. It represents ongoing maintenance and operational issues. If you MUST have glycol, you will need a larger pump than what you have to get the fluid moving in the proper manor, and actually may need to over pump the system to make all problems go away.

ME

smuth10

No, 5 gallons glycol and 10 gallons water so 33%. I have attached a pic of the chart on the bucket. It is called Super Noburst

I live in SE Michigan and the temps get down around 0 from time to time and we do go on vaca in the winter every year. The thought of coming home to burst pipes under my slab is why I have the glycol in there.

The pump seems to working fine with the 30%. I am getting 1.6 gpm with the low setting, 1.9 with medium and over 2 on the high setting.

I put the balloon on the spiro and started it up this morning. It is quiet right now so fingers crossed.

In your opinion would I be having this problem if I had used a boiler? Are they better with a glycol solution?

smuth10

Took about 2 hours but the noise is back

Brewbeer

Does the noise start when the tank reaches a certain temperature?

Maybe drain out the glycol and try testing it with straight water to see if that changes anything?

smuth10

Most times the noise starts right away, but sometimes it takes 15-20 minutes or even an hr or 2

It is supposed to 40 here tomorrow so I am going to try that

smuth10

I was in the shop tonight and noticed the heater was running and there wasn't any vibration. It was super quiet. After being in there for a few minutes I heard the exhaust fan(I think, some sort of fan) kick on and the noise immediately started. Not sure why I did not notice this before, but I think the fan usually kicks on with the hwh and that is why the noise is instant most of the time.

Could this be a dirt or dust problem? Seems like if it was a glycol problem it would do it all of the time and not have anything to do with the fan

smuth10

I put my hand over the exhaust and it shut the fan speed down to low and the noise stopped. What does this mean?

BobC

The blower may be unbalanced, it should be checked and cleaned if necessary.

Bob

Mark Eatherton

It still indicates a problem with excess glycol, poor heat transfer and steam flash occurring at the fluid/heat exchanger interface. The burner won't fire unless the exhaust fan is on, so all you were originally hearing was the fluid being moved through a cold/off appliance.

As soon as the appliance fired, the noise picked up. I supposed fan imbalance could be a problem, but with it being brand new, I seriously doubt it is any kind of dirt accumulation on the fan.

I am reviewing the I&O manual for this appliance, and have yet to come across the section regarding space heating use and he use of glycol. Not being familiar with the appliance, I don't know (but suspect) it is going directly to high fire on ignition, and will eventually modulate back. Still researching. Patience grasshopper, patience...

Quick test. Send the boiler into a call for heat. Once it fires, and starts rocking and rolling, turn the gas supply valve OFF, and see if the noise stops.Fan should continue running through post purge. If yes (noise ceases), then it is definitely a fire side issue related to the use of glycol. Your control should send you into a lock out condition, which you will need to reset. Won't hurt the appliance.

ME

smuth10

Mark,

The hwh is fired when the fan is on low and there is no vibration. I can see the flame and outside there is a small amount of exhaust coming out. The noise comes in only when the fan kicks on high. I will double check this today, but I am pretty sure that is what I am seeing

Mark Eatherton

In the voice of an NFL referee.... "After further review, the ruling on the field has changed..."

Based on the drawings, it appears that there is a crossover connection between the cold inlet and the hot outlet with possibly some sort of control valve placed between the two connections. The function of this (my assumption) is to "extend" the availability of DHW during peak loading.

In other words, a high boiler discharge temperature, combined with a cold water mix down = more GPH of medium hot water. During normal operation as a space heater connected to a slab, as the cold water is entering the appliance, its control sees flow, and a low temperature of discharge and low inlet temperature, so the bypass valve is closed.

As the return water and supply becomes warmer, the discharge from the heat exchanger becomes warmer, and the appliance thinks it needs to bypass between the cold and hot water lines to temper the water down. When the bypass is opened, flow through the actual heat exchanger drops, and viola, steam flash and associated noise/jumping occurs. Glycol significantly compounds this heat transfer/steam generation problem. Eventually, once the appliance settles in to a given space heating load, you will hear strange moaning sounds and something that sounds like whales in heat. That is the effects of glycol on the heat transfer process. You can verify this by closely watching the pressure gage on the appliances outlet. If it is jumping and bouncing at the same time as noise is generated, your experiencing micro-bubble steam flash.

As it pertains to their mechanical drawings, they are not even right. In their combo system (they don't even show an application for space heating only like you have, and as such may void the warranty on your appliance due to misapplication) they have their pump pumping towards the PONPC. Never a good idea. Ideally, hydronically speaking, beginning with the return fluid coming back from the manifold, the fluid should go through the air separator/expansion tank (Spirovent), then through the pump, then into the boiler, then out of the boiler and into the supply manifold. Piped this way, the pressure generated by the pump will always be the highest in the combustion device, and negate (but not eliminate) the possibility of steam flash occurring during NORMAL operation. So, if you want to set the system up perfectly", you should re-pipe it. It will probably work the way you have it set up, but it still isn't ideal and problems can be expected. While you are at it, throw a ball valve in before the pump, with a drain cock on both sides of the ball valve to assist in fill and purge.

The appliance has probably never been approved as a space heating only appliance, hence the reason they don't even have a drawing showing it in that application. It is approved as a combo space heating/DHW heating appliance, but NOT as a space heating appliance only. For the benefit of those reading this thread that are considering using it as a combo appliance in a potable water setting, I DO NOT recommend it.

Think Legionairres disease, pontiac fever and a whole host of other nasties.

You need to go through the manual, and by the way, sounds like you may have fuel supply issues based on the fault code (991) that you are citing. That warrants a call to the manufacturer and is probably going to require more technical expertise and tools than you have at your avail.

You should also try turning the set point up (dip switch settings) to a higher temperature to keep the bypass valve closed.

Based on years of experience, and not trying to denegrate you or your application, but these appliances are made for a LARGE differential in temperature across their body as a whole. Water comes in a 40 and leaves at 115 degrees F for example.

When applied as a space heating appliance, you will rarely see more than a 20 degree F rise, and the appliances control thinks it is overheating the water and will shut down, creating a burner short cycle condition. Short cycles are only good for circus clowns

Go back through the manual, making certain that all dip switches are appropriately set based on your application. If you haven't already, change the set point to the 140 degree F option.

If that fails, resort to the 888 phone number to the manufacturer. no one knows that appliance like the manufacturer. And check your fuel supply.

ME

Gordy

Mr. Meyagi has spoken. Makes sense. Don't know what's up with the dyi sit you got the idea from. If they are having issues or not as such. Same hwh?

smuth10

Whales in heat, that is exactly it. I can hear the fluctuation on the hwh standing next to it. Up and down. Does this add air to the system?

Yes, I will probably re-pipe it as you say. I already have the ball valve in there with the two gate valves for filling, but they are after the pump. I take it you are saying they need to be moved because it is not the best location?

I know what you are saying about the hwh not meant for this application. I just don't understand why so many others have the same setup as me and do not have problems. I guess I am just lucky.

I have someone coming over this weekend to test the gas pressure for me.

I will try 140 and see what happens

Here is a link to many setups similar to mine using the Takagi hwh's.
http://www.garagejournal.com/forum/showthread.php?t=49557

At this point my choices seem to be to change over to water only or to purchase a boiler. I am assuming boilers are rated for glycol use? What would you suggest as I really don't think not using glycol is an option for me until I have a backup generator installed.

Thank you again Mark and Gordy!!!

Mark Eatherton

If you pipe it such that your charging pump pushes water into teh inlet of the circulator, the pressure capacity of both pumps will give you some extra umph to push the syrup around the circuits, and get it purges better/quicker.

I tried looking at the pictures in the GJ site, but required me to join, which I am not interested in. I'd just get frustated by alleged "experts" on the site misapplying hydronics :-) Probably one big difference is your use of the glycol. As soon as you can get it out, the better your system will operate.

As far as purchasing a real boiler is concerned, that's really your call. As it is now, I seriously doubt you have any kind of warranty based on thier warranty statement. So long as it works to your needs and expectations, and is safe in operation, you will probably be OK. Consider it a "throw away" boiler.

Any boiler can work with glycol, just not up to the specs considered for water. And as has been stated, glycol comes with some fairly ugly baggage (viscosity, exchange, maintenance, extra enegy consumption, and noise). Use only when necessary, and then at as low a concentration as possible. More is not better with glycol.

Let us know how turning it up went. I rarely recommend that, but in your case it may make all the difference in the world. You still might want to consider contacting the factory. Sometimes, they have dip switch configuration settings that are not included in their manuals that may create a work around to your problems.

Also, the flame height is directly proportional to the fan speed, and confirms my suspicions of micro bubble steam flash.

Good luck.

ME

smuth10

Not really sure what to do here. I would love to tear everything out and replace it with a boiler, but don't think I can swing the cost right now. That leaves me with switching over to water.

I have an email into the manufacture with some questions about this unit being rated for radiant heat only, glycol and a few other items. I tried switching to 140 degrees and it is not working. Followed the instructions per the manual and tried several times. It will not go past 120 degrees. Hopefully there is something wrong with this thing and I will be able to return it. If so I may just get a boiler.

What boiler manufacture do you use for your installs?

Difficult question, but if you were in my situation would you use glycol or not?

Gordy

Do you intend to keep the space conditioned? If yes move to next question.

Do you have frequent disruption, and or lengthy power outages? If no move to next question..

Do you leave town for extended durations frequently during heating season? If no

Then ditch the glycol.

smuth10

I am leaning towards doing just that. We hardly ever loose power here.
We only leave in the winter for maybe one week. I am going to look into a backup power supply for the time being, but I have a portable generator if it goes out while we are home.

I did not have time today, but I will switch over to water tomorrow and let you guys know how it goes.

Can't thank you guys enough. I really appreciate all of the time you have spent on this. Cheers!

Mark Eatherton

If you have a telephone line out to the garage, http://www.controlproductsonline.com/freeze-alarms-c-16-l-en.html

It is ALWAYS a good idea to have a friend go by your home and or shop just to check on things. Hoses break, and stuff happens. Having someone check on it will give you peace of mind, and might not cost you more than a nice dinner for your friend.

When you blow the glycol mix out (use compressed air), save it in case you decide to put it back in later.

ME

Mark Eatherton

smuth10 said:

Not really sure what to do here. I would love to tear everything out and replace it with a boiler, but don't think I can swing the cost right now. That leaves me with switching over to water.

I have an email into the manufacture with some questions about this unit being rated for radiant heat only, glycol and a few other items. I tried switching to 140 degrees and it is not working. Followed the instructions per the manual and tried several times. It will not go past 120 degrees. Hopefully there is something wrong with this thing and I will be able to return it. If so I may just get a boiler.

What boiler manufacture do you use for your installs?

Difficult question, but if you were in my situation would you use glycol or not?

As the director of a non profit org that promotes radiant heat (Radiant Professionals Alliance.org) and has boiler manufacturers who are my members, I can't afford to recommend one appliance manufacturer over the other, so I will abstain from answering that question and let some of the contractors who frequent this site make recommendations for you.

I think you know my thoughts on the use or non use of glycol. It has it place.

ME

smuth10

So the 140 degrees worked. Where am I sending the scotch?

It started to vibrate as it started up and as soon as it got to temp the noise stopped. I turned it up so it would run for a while and not a peep. Still not sure I understand why a higher temp would help glycol boiling, but it works. The higher speed on the fan never even kicked in. Are there any downfalls to running at 140? I noticed the return temp is still around 90 so I now have a 50 degree difference instead of 30. I don't think it runs long enough now to be any closer. The shop heated up in no time today.

I also had someone test the gas pressure and it is right where it should be.

I may still remove the glycol down the road, but for now I have a warm shop to work in.

Thanks again to everyone here for all of your help!!!

Mark Eatherton

I suspect it has to do with the bypass closing and keeping the flow across the heat exchanger at max flow, with no bypass.
Send the scotch to Mr. Holohan, who makes this forum possible. We are here to help.

You may have to turn your room thermostat down, otherwise your slab may overdrive the room temperature due to the higher operating fluid temperature.

ME