tdkkart
Well-known member
The boiler that he is using is the same one I have(mine is 14KW), and it is activated by the water flow only. Thermostats control the pumps, the boiler sees the water moving and turns on. very simple and reliable.
MY home made radiant hydronic floor setup saga.
- Thread starter JohnnyMac
- Start date
Per your recommendation , ordered 2 of these.
Over my head on how these will be different, but we'll see. you obviously have a better understanding than me.
https://www.supplyhouse.com/Grundfo...YpAr_uOdK2Bk6k77wu8NEjInld6MjpWoaAvOpEALw_wcB
thank you,
I didn't pay any attention to the pumps either. You need high head pumps for floor heat and also for these tiny high efficiancy boilers. At a given pressure the 1558 Grunfos will pump twice the pressure of the Taco 007.
All, thank you for your help and support to this point. Was out of town so just getting back to it.
I'm struggling to get the floor loops warm. Does initial heat cycles usually take days?
Boiler loop(post boiler) is HOT 140+F. It's calling for heat and working as it should.
Boiler loop pre Boiler is cool. Only 50F degrees.
Ambient temp has only been in the 40's for last few days.
Is the cool ground temp just making it too hard to get heat in the concrete? Is it just super cooling my hot water from the boiler loop?
No air in system. Pad is insulated. Flowing well. Even replaced the pumps as suggested.
Any advice would be great!
I even closed off some loops...seemed to gain a little, but not much. Maybe put the floor loop on a lower pump setting to force more hot water in??
Thank you!!
I'm struggling to get the floor loops warm. Does initial heat cycles usually take days?
Boiler loop(post boiler) is HOT 140+F. It's calling for heat and working as it should.
Boiler loop pre Boiler is cool. Only 50F degrees.
Ambient temp has only been in the 40's for last few days.
Is the cool ground temp just making it too hard to get heat in the concrete? Is it just super cooling my hot water from the boiler loop?
No air in system. Pad is insulated. Flowing well. Even replaced the pumps as suggested.
Any advice would be great!
I even closed off some loops...seemed to gain a little, but not much. Maybe put the floor loop on a lower pump setting to force more hot water in??
Thank you!!
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like2wheel
Well-known member
According to your gauges at the manifold, there is no hot water going out to the floor.
Looks like it reads 40° at both ends of your loops.
Is the primary circulating pump turning on?
Looks like it reads 40° at both ends of your loops.
Is the primary circulating pump turning on?
Yes its running. The flow meters are at 3/4 deflection.
I closed all the loops, and opened 1 at a time. At one point I had the lower gauge at 70, but I opened 2 more loops...and apparently overnight it sucked the heat out of it.
Both pumps have to be running, as the flow meters (the open loops) are 3/4 deflection down, and it's getting a hot water call on boiler loop, which is only flow activated. I think anyways??
I feel like I'm missing something stupid.
19D2P
Well-known member
You still have no insulation In the building.
For comparison I have a 40x60 like you. It’s 5” thick with 2” XPS under, 3” at the perimeter going 24” down and 24” horizontally. I turned my system (18K Thermolec boiler) on when the slab was 10F to warmup the building as much as I could to help the CCSF application. After 8 days the slab could not get over 40F due to the heat loss into the uninsulated building.
Applied the CCSF and in 36 hours slab went from 40 to 62.
For comparison I have a 40x60 like you. It’s 5” thick with 2” XPS under, 3” at the perimeter going 24” down and 24” horizontally. I turned my system (18K Thermolec boiler) on when the slab was 10F to warmup the building as much as I could to help the CCSF application. After 8 days the slab could not get over 40F due to the heat loss into the uninsulated building.
Applied the CCSF and in 36 hours slab went from 40 to 62.
19D2P
Well-known member
I agree with @like2wheel the ”secondary” loop feeding the floor is not pulling anything from the “primary” boiler loop. If temps on supply and return are identical, and matching the ambient, the floor is recirculating the same fluid over and over.
19D2P
Well-known member
If it was my system, I’d close the valve at the closely spaced T’s and within two minutes if the supply manifold the temp gauge goes up, you know that’s the issue.
I guess I thought at least the pad would warm....the concrete isn't even remotely trying to warm.
It's getting sprayed in a few months. For the simplicity of the thread I may have stated it was already done. Sorry for my fib there.
I guess I'm shocked to learn the pad won't even get Luke warm without the building being insulated.
If I close all the loops off, but 1, it gets warm down to the manifold and goes to 70 degrees. I can do the same with moving the t to closed.
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Possibly!
What was the floor temp when you started? Consider you have a roughly 100,000 pounds of concrete to warm up, plus no building insulation. Plus the boiler is sized for a building that is insulated, a finished building. The floor will never get warm. It may get 10-15 degrees about ambient temperature, but the cold air will draw all the heat out.
Right now with no insulation you have basically a snow melting loop and snow melt needs 100 BTU per square foot, or about 4x the BTU your boiler will produce.
19D2P
Well-known member
I was just giving you a data point. My ambient temps were 10F daytime so a Delta T of 30F was all it could do. You have the advantage of higher ambient temps.
I think the system isn’t working correctly though…
Okay taking your follow up info I believe your floor (I’ll call it secondary) loop has all the flow through the CST junction. I base it on:
1) the temp after the boiler is 140 but the gauge below it shows water only at 50ish meaning there is no circulation through that loop
2) supply and return manifolds have identical temps showing flow through the floor loop with no injection of heat.
3) closing the closely spaced T sends heated water to the manifolds.
If you watch that video on primary/secondary by Caleffi I think you can find some ways to improve the function of your system.
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American Locomotive
Well-known member
I agree with 19D2P that your system is not working correctly.
You have an 88°F temperature delta across your boiler, which is absurd. The boiler having a leaving temperature of 140°F is a red flag by itself. That's the maximum temperature the boiler can produce, suggesting the boiler is actually bumping up against an internal limit and modulating to stop from exceeding that temperature.
With your Grundfos circulator set to high, you should have roughly 3 GPM of water flow through your boiler. 3 GPM @ an 88°F temperature delta is 132,000 btu/hr, or 39KW, which obviously isn't possible. So something doesn't jive here. The only way you are going to get a temperature delta that high with that boiler is by having very low flow.
Either your pump is running on "low", or there is a huge restriction somewhere.
You have an 88°F temperature delta across your boiler, which is absurd. The boiler having a leaving temperature of 140°F is a red flag by itself. That's the maximum temperature the boiler can produce, suggesting the boiler is actually bumping up against an internal limit and modulating to stop from exceeding that temperature.
With your Grundfos circulator set to high, you should have roughly 3 GPM of water flow through your boiler. 3 GPM @ an 88°F temperature delta is 132,000 btu/hr, or 39KW, which obviously isn't possible. So something doesn't jive here. The only way you are going to get a temperature delta that high with that boiler is by having very low flow.
Either your pump is running on "low", or there is a huge restriction somewhere.
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TurnipTruck
Well-known member
I first fired the hydronic system in my insulated 24x60x14 Quonset on a Halloween, probably 20 degrees out and a little snow. The 100k btu boiler ran for 23-24 hours before the call for heat (55*) was satisfied. The walls were foamed to R21, the floor had R7. (21 years ago)
Regarding your system:
if the boiler is bumping against the hi limit then the pump is working but could be bigger or is fighting a restriction. I don’t know the rated delta P across the boiler but you have 7 psid, seems reasonable to my unschooled eye.
What is the total flow through the floor manifolds? Does it change when the boiler circ is off? Does the indicated flow double with half the loops on? As an experiment I would run each single floor loop one at a time overnight to thoroughly purge air and compare flows looking for flow rate differences. Maybe gunk got in some loops.
Regarding your system:
if the boiler is bumping against the hi limit then the pump is working but could be bigger or is fighting a restriction. I don’t know the rated delta P across the boiler but you have 7 psid, seems reasonable to my unschooled eye.
What is the total flow through the floor manifolds? Does it change when the boiler circ is off? Does the indicated flow double with half the loops on? As an experiment I would run each single floor loop one at a time overnight to thoroughly purge air and compare flows looking for flow rate differences. Maybe gunk got in some loops.
like2wheel
Well-known member
Full disclosure; I am a complete novice with this. I don’t even have my own system plumbed up yet. But I don’t understand how insufficient building insulation could cause this problem.
He has 140° leaving the boiler, but even if he closes the valve between the closely spaced tees, he only gets 70° at the hot side of the manifold? That’s a lot of heat loss in a few feet. And and with it open, he has absolutely no Delta across his loops?
And If he closes down his loops, wouldn’t his leaving and return temperature have to be almost equal?
Almost seems like he has no circulation on the primary loop, and the temperature is just migrating by conduction up the piping from the boiler.
He has 140° leaving the boiler, but even if he closes the valve between the closely spaced tees, he only gets 70° at the hot side of the manifold? That’s a lot of heat loss in a few feet. And and with it open, he has absolutely no Delta across his loops?
And If he closes down his loops, wouldn’t his leaving and return temperature have to be almost equal?
Almost seems like he has no circulation on the primary loop, and the temperature is just migrating by conduction up the piping from the boiler.
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American Locomotive
Well-known member
The fact that you can get the boiler return pressure gauge up to 26 PSi with no increase in the supply pressures indicates you have a restriction in the boiler somewhere limiting flow.
Try back flushing the boiler.
Try back flushing the boiler.
Will do. That Makes sense.
Kezorm
Well-known member
Yep. Floor loop seems to be circulating fine on its own (valve open in closely spaced tees). But you don't have any significant flow through the boiler loop. No heat getting injected into the floor loop. With the valve closed, you have a 10+ psi drop across the boiler. That thing is plugged up.
American Locomotive
Well-known member
The spec sheet in the manual goes up to 4.7 GPM. The manual states with a 12 PSI differential (which he was getting in the most recent video), there should be 4.2 GPM through the boiler.
That would be 185,000 BTU/hr or nearly 54KW with his temperature differential IF that much water were actually flowing.
That would be 185,000 BTU/hr or nearly 54KW with his temperature differential IF that much water were actually flowing.
Kezorm
Well-known member
Exactly. The flowmeters on the floor loops tell the real story - almost no flow through the boiler.
kj_mustang
Well-known member
Am I seeing air in the upper part of all the flow guages?
Video update.
Backflushed boiler, and I am in fact getting crud out of it. I now have flow through the floor both with the t valve open and closed, and through the boiler. Working much better
I think I need to actually flush the entire system at this point. The system sealer I bought for initial fill I suspect is my culprit.
I'm getting small gel like balls with hard solids in it. I don't know what else it could be. I blew out the lines with air before all the pex was laid, and obviously built the system from scratch.
You guys with the blockage suspicion were dead on.
Working great now, but i suspect its just going to keep clogging until i flush/filter the entire thing.
maybe i can add one more filter of some kind before the boiler thats easier to clean than the strainer.
Backflushed boiler, and I am in fact getting crud out of it. I now have flow through the floor both with the t valve open and closed, and through the boiler. Working much better
I think I need to actually flush the entire system at this point. The system sealer I bought for initial fill I suspect is my culprit.
I'm getting small gel like balls with hard solids in it. I don't know what else it could be. I blew out the lines with air before all the pex was laid, and obviously built the system from scratch.
You guys with the blockage suspicion were dead on.
Working great now, but i suspect its just going to keep clogging until i flush/filter the entire thing.
maybe i can add one more filter of some kind before the boiler thats easier to clean than the strainer.
The goop, my strainer, and by mesh bucket strainer catching goop when I empty it. The product was base hit II. What junk that garbage is. Since I fought the npt fittings sealing when air testing....thought it was a good idea. Obviously not.
This small passage in the boiler is probably where it gets stuck.
This small passage in the boiler is probably where it gets stuck.
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I was wondering about that, but didn't bother with the math. The supply temp of the boiler shouldn't be more than a few degrees over the return temp.
I just ran the numbers quickly, yep, its is plugged up! At about 1.5 GPM through the boiler at full output to get a 90 temp rise. If it were getting full water flow, one chart I saw showed up to 6.5 GPM, it would have 20 degree rise. 4.7 GPM at full output will get about 28 degree rise.
Did you replace the boiler? You mentioned blowing some **** out of it. Sounds like you need to flush it some more!
American Locomotive
Well-known member
Magic sealing stuff should never be used, as it causes problems just like this. There is a reason why multiple people said not to use it. You will know when you have your boiler flowing well by the temperature differential.
Assuming all 19KW is going into it, at 3 GPM, you shouldn't have more than a ~40°F temperature differential between the supply and return on the boiler.
Assuming all 19KW is going into it, at 3 GPM, you shouldn't have more than a ~40°F temperature differential between the supply and return on the boiler.
I agree. I just need to keep straining/flushing. I thought I got all the junk out of it the first time, but apparently not.
Yup, lesson learned.
I missed the part about the sealer.
I wonder if a whole house filter wouldn't help to get the sealant out of the system. Install it right before the boiler instead of the Y strainer.
Of course you would need to find one that can handle the water temp.
https://www.amazon.com/dp/B0167FZCP4/?tag=atomicindus08-20
It will take forever to get all the sealer out of the system running normally. Even if you flush it I wonder if you would get it all. Plus you will have to replace the glycol.
On a side note I find it shocking how that boiler has such small passages and will plug up so easily.
I thought that same thing about the filter.
In the one video you can see how small that crossover pathway is. I backflushed the entire system, and emptied it. And flushed with distilled water. Completely, 100% replaced the fluid with non diluted cryo tec 100.
This guy seems like it would be easy to plumb in on the return side of the boiler. I can't see my temps on that side getting too high. Or the one you found if I have the room.
SimPure 40/200 Micron Spin Down Sediment Filter, Reusable Whole House Sediment Water Filter, Pre-Filtration System for City/Well water, 1" MNPT + 3/4" FNPT + 3/4"MNPT, BPA Free https://www.amazon.com/dp/B082174CB9/?tag=atomicindus08-20
It's working now, but I am still getting a little stuff out of the strainer I'm amazed how much trouble that junk made.
The only debris in the system now can be what was missed by 2 flushes, forward and backwards, and replacing 100% of the fluid.
I may still throw a filter like that in line. It's very minimal what I'm getting out of the strainer, but the fact it's any, shows there is still some residual somewhere. Be it small.
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billybaru13
Member
- Joined
- Oct 27, 2021
- Messages
- 5
Good read here. Are you able to set the boiler to any temperature you want? I dont see any sort of temp mixing valve in your setup.
Hey, you can turn it up or down on the boiler. So that's how high the boiler operates. The wall thermostat is what dictates if it kicks off and on to regulate air temp. If that makes sense.