Radiant heat disaster
Greeting folks,
I am in severe need of some help. My wife and I are currently renovating a home with in-floor radiant heat. I am attempting to put the system back into working order. Unfortunately, I cannot sort how the previous owner had this hooked up. I have been able to reconnect the in-ground lines into the manifold with minor issues so far. The most challenging portion is sorting how he had the outside boiler connected. The two red and two white 1in pex running through the wall and held in place by the spray foam run outside to a concrete pad where they end. The boiler that had been there was removed years ago and it is unclear if he had a pump at the boiler.
Any help or insight anyone could offer would be greatly appreciated.
Note: the white PVC is for potable water and not connected to the system at all.
Comments
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The fact that it has been decommissioned would make me suspect that it wasn't working when it was taken out of service.
There are so many stories of people who just build heated floors without designing them. They figure it's gotta work. Actually, it doesn't. There's a good chance that with a system like this even if you get it back working as designed, it's not going to work that well.
I don't see any zone valves, which makes me wonder how it was controlled.
Even though you've hooked it up, I would start by blowing compressed air through each loop to make sure it's not obstructed, and to make sure you have the loops matched up properly. I would want to know the length of each loop and where it goes. If they're not labeled I don't know how you figure out where they go. You could figure out the length of each loop by pumping water in with a pump and measuring how much water it takes to fill it.
Once you figure out what you've got under the concrete, we can talk about how to figure out how much heating you need and how to configure it.
What kind of heat are you considering? The fact that the old boiler was outdoors makes me think it was wood or something weird like that. That's another warning sign.
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We were told that the system did work previously but the system was drained when the previous owner moved about 30 minutes away and did not want to return on a daily basis to fill the coal/wood boiler (and the fact that the neighbors constantly complained about the coal smoke). The building sat empty for several years and was used as cold storage. From what i can tell the zones are controlled by thermostats which run pumps through relays, the three black boxes on the wall.
Fortunately, some of the lines are labeled as to the zone they run to/return from but does not include length. Ill work on blowing compressed air through the lines. When we are able to run water through the lines we are going to attempt to map the lines and label them by using a thermal imaging camera.
At this point I have purchased a wood boiler that will be delivered next week. I am starting to fear that i jumped the gun on that a bit.
Thank you again for your time.
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you might build a test gauge to fit onto that Pex and test one loop at a time, 60 psi will show a leak quickly. A test gauge on one end, shark grip cap on the other.
Or get a gauge like this with a female hose adapter. Screw it onto the drain valves on the end of the manifold and isolate the loops to test one at a time. That will be quicker than taking every loop off the manifold.
Any idea where the loops run to?
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Looks pretty normal.
Circulate water though the exterior red pipes (so your wood boiler needs its own pump) and run the pumps to heat. You wire your thermostats to the black pump relays, these also have 24V supply if your thermostat needs it.
The plate HX can also be used to heat your hot water, depending on which direction your flow your boiler water, it can be priority over floor heat. No controls, but shouldn't need any.
Once you get it plumbed up and running, check the temperature setting on the mixing valves since you don't know what they are set for.
The white pipes might have been for a dump zone for the wood boiler.
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Pressure testing the loops is an excellent idea, basically you want to be as sure as you can be that it's going to work before investing time in it. My standard test kit is a pair of Sharkbite washing machine hookups:
Put one on each end of the PEX. At one end put an RV blowout valve to connect to your compressor:
At the other end put a pressure gauge. If you want to let it sit for 24 hours you can close the valves on the Sharkbite fitting.
The reason I ask about controls is it looks like all of the zones are on the same manifolds with nothing between the manifolds and the loops. So all of the zones are on or off together. What is the heated space like? Is it all one big room or a lot of little ones?
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Honestly, just start over. Leave the pumps, heat exchanger, and mixing valves (and maybe the copper and manifolds if you don't care about looks or functionality) but throw everything else away and start fresh. Wood boilers are almost always piped wrong and this is no exception. The underground lines (assuming they are the same non barrier tubing in the picture) are filled with groundwater now and will give off more BTU to the earth than the building. Dig them up and bury a single set of good foamed lines such as Thermopex, Rhinoflex, Insulpex, or Logstor. Nothing else is worth burying. You're going to need to flush everything to get the atmospheric crud from the previous boiler out of the lines, and to do this properly you'll need an additional heat exchanger (unless you don't want domestic hot water, which is the function that this one was previously serving, then you could reuse it for the radiant) and pressurize the whole radiant system with the appropriate closed loop components and piping.
The old wood boiler had a pump (or two) on it which circulated 24/7 through that heat exchanger on one loop and the white tubing on a second loop. Those two tees to the left of the heat exchanger allowed either of the two right zones to draw hot water from one through the mixing valve(s) and return cooler water back into the other as some sort of primary/secondary loop but it's very poorly executed. I do these wood boiler systems quite often and if this were my job, I'd throw away every component besides possibly the pumps and heat exchanger.
What make/model wood boiler did you order?
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So @GroundUp , just to clarify, you think the infloor loops need to be junked too?
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I think this is a bit of an over-reaction. Just because the original build used plastic and sharkbites, it doesn't mean it wont work. All the bits are there. Not pretty but will work.
I do agree about the underground insulated pipe, wrong insulation can get saturated with water over time making it ineffective. If your wood heat is cheap, not a big issue, you can look at it as free snowmelt.
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The loops behind the sink are labed as they go to the second floor of the residence. The other sections I assume go into the concrete for the garage and first floor of the residential section.
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I ordered a central boiler edge 760. From your feedback my assumption that the previous owner was intoxicated when he installed the system may have not been far off.
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Nothing overreactive about it. I never said anything about the plastic or shark bites, nor that it wouldn't work. I said it's piped wrong and should be started fresh to have a proper system.
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Meh, it's a lack of knowledge more than anything. I've seen hundreds of OWB systems installed by "professionals" that look worse than this. The biggest thing with OWB is that most owners are burning wood to save money, so they often end up hiring the cheapest plumber they can find or do it themselves with some guidance from their uncle Bob's dog's neighbor's brother in law and they end up with a clusterF like you have on your hands. The beauty of hydronics is that it's very versatile and even the crappiest of installs will still move heat from one place to another, but almost never are these OWB systems done correctly and yours is no exception. If you want it hacked together, it wouldn't be tough to make a few connections to what you have and make it work. If you want it done properly, starting over is your only option.
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I can only assume you're attempting to be facetious, but it's not working.
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Not facetious at all. Just not sure if when you say "throw everything else away" you're including that. Because I agree that the OP is probably better off assuming that nothing on that wall is going to be of use. But it seems that if the in-floor coils aren't leaking or crimped they're pretty hard to screw up.
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@DCContrarian it's painfully obvious that I didn't suggest he tear up his floors. Furthermore, I quite literally stated that the manifolds, etc could stay as-is if he doesn't care about aesthetics.
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Lets objectively look at what is wrong with the setup.
1.The two loops share the same takeoffs so they are not hydraulically de-coupled.
2.Open system, no isolation.
3.Questionable underground piping.
1.This is a non-issue if the pumps have an IFC.
2.Most of the bits there don't care about oxygen. The pumps will rust. Sample of one, but I have cast pump on well water and going for over a decade, so they might be replacement item every 5 or 10 years. Wood boilers are maintaince, so that is not a huge item. The cost of doing this properly (HX,pumps, feed, regulator, expansion tanks) is many times more than the cost of budget pumps. You can also replace pumps with brass/stainless when they fail.
3. If your fuel is cheap, replacing that is not worth the cost of digging plus pipes. Doubt that juice is worth the squeeze.
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Looks like it had a plate HX for separation? Or is that a DHW HX?
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
That's for DHW
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have you pressure tested the system?
Ran water through to determine what line is supply and what one is return?
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