DIY In-Floor Hydronic Heating System Using Water Heater 

A really good attempt. Here are some helpful tips... Water temp coming back to heat source should be 15 degrees cooler than going out. This way your heat source can keep up. Do this by closing your out going on/off valve a little at a time to slow the speed of circulation till the water comes back 15 degrees cooler. This gives the concrete time to pull the heat out of the water/ tubing. Slowing the circulation speed wont hurt the pump because they have an automatic bypass built into them. 2nd tip. You have way too much plumbing on the wall and its not insulated.(severe heat loss and inefficient) From where my hot water comes out of my hot water tank to where it goes into the floor is only 4 feet. Cooler water coming back out of the floor to reentry to the tank is 4.5 feet.(insulated) 3rd tip. Connect a water supply to the system with a backflow preventer in place with a 3 pound pressure reducer. Lower the pressure in the expansion tank to 3 pounds also. Why? because you want the pump to control the speed of circulation ( Not the city water pressure or the pressure from the expansion tank) and also, even though this is a closed system, water will disappear and you will need make up water. 4th tip. Scrap all the temp/ thermostat control stuff and buy a 120 volt 7 day 7 event programmable timer... I program my timer to turn the pump on and circulate a fresh batch of hot water 3 times per day for 2 hours each time. In between runs, the concrete constantly pulls the heat out of the water/tubing. As weather gets colder/ warmer , you can add or delete how many times the pump turns on. Follow these steps and you will have your system dialed in. Good luck.

Your reasoning about getting a hot water heater and saving money is spot on and I bet your water heater lasts a lot longer than 5 years.

Most important part of any job is. The prep. Great job!!

Nice work. I appreciate you taking the time to make this video. I look forward to assembling my system. This has boosted my confidence.

Love the video. I am also in Ontario, eastern. I am in the process of hooking up my system. I have a much smaller space, 600 sq ft. garage. I have my hot water tank already. This was very helpful.

Tinkering to find the sweet spot, your an intelligent dude! That same concept could be applied to every heating system, im still tweeking mine 5 years later, great info and demonstration of your heating equipment, you know more than any electrician i know! Great great video!

I sat down this morning and throughly enjoyed watching your video. And I read all the comments. I learned some things. I think you are to be commended for both doing this project and for posting it. Thank you. I am planning a system for my own house and will probably do a lot of what you did, or what was suggested in the comments. It works! Congratulations!

Great video I've had my system in for about 10 yrs with a single pole thermostat and always had control issues. My shop is 24x36 I'm just north of Ottawa. Thanks again great info.

I love getting to see people pulling off their grand machinations without significant compromise.

In both design of your system and in sharing it so clearly with so many other, you are a genius! Bravo! Live long and prosper!!!!

Excellent!! I have a friend in Alaska that is heating a 50x50 aircraft hanger with an in floor system such as you have and using a 50 gallon electric hot water heater to maintain. Now I know how it's done. Thanks

We used 3 tanks over 8 -9 years ago still running. Seems like we have multiple pumps too our wash bay and spray both are t shirt comfortable. Nice set up

The best video I have seen after watching 20 or so videos. Thanks!

My name is Tim I live near Peterborough Ontario. Just want to give a great big thank you for taking your time to explain this. you’ve done a really good job at simplifying this and it looks great.

Nice setup! Thanks for sharing.

I found your video while researching how to put a floor heating system in a house I want to build. I am trying to build something simpler. Thermosiphon, so no pumps. I will use my diversion power from my wind /solar power to run an electric water heater. After watching the video and reading the responses I will have to look into boilers. I thought small water heaters were expensive here until reading about how much they are where you live. maybe a water heater in a closed-loop system with glycol. I've read about using a mixing valve and an air bleed. Buried Pex tubing with shark bite fittings that are all above my earthen floor. Very informative video.

Thanks for making the video, excellent job with the installation and system explanation.

This has given me ideas to include in a out door wood boiler feeding a water mass to in ground heat. I was actually thinking of using straw instead of wood. Once or twice a day throw a small square bale in the boiler to heat the tank. Then using that to heat the house. 1000 gallons storage in a high insulated outbuilding or in home room.

Thank u for making this video. It’s what I’ve been thinking about doing but there’s not a good video explaining it. Yours is very informative. That’s a good looking system. Great job.

Great video of a very nice build. Excellent explanation too. 👍

Love that. Stapler contraption! My boyfriend and I work well together. Glad to see you and your wife working together. By the way, I am 62, my boyfriend is 73🥰😍

Nice job I will be installing a similar system with the addition of wood heat and use the water heater when I’m gone

Thanks for explaining everything!

A guy told me his floor got too hot for some reason and it heaved like a hi-way does in hot summer. Destroyed the floor and heating system. Thank you for this great video!

In floor heat is the best! I put it in my shop and the floor is 80 degrees F. Snow/ice melts off and vehicles are dry within just a couple hours. It's a different kind of heat than forced air. Much much better.

Nice setup. Ive been trying to figure ways to heat a 40x80 shop build for basically as little money as possible naturally and on the fence over wood, oil or gas. Radiant floor heat, radiant tube heaters, forced air unit heaters, a wood burner with waste oil drip and a heat exchanger and also a waste oil forced air or boiler systems. There's so many pros and cons to each setup im still not sure what i will go with but you gave me another option to think about. Thanks for the tour and explanation.

A very simple system, no mixing valve, zone valve, check valve, pressure reducer. Air scoop should be on upper section, pump mounted low, no black pipe. You proved the system works well to those who say it can't be done. Nice work!

I've had PEX in my garage floor since 2015 and I'm just now trying to get a system put together to actually have some heat out there. You've got some good info here, thank you. I picked up the same pump you've got and some manifolds, trying to figure out my thermostat and heat source now. I'm actually considering hooking up a used water heater initially to see how it works.

I have same to do in shop House is all done with boiler Same thing I don’t want to spend For another boiler for shop Great detail on video thanks

To help your water heater keep up you could install a tempering valve. The hot lead would be hot, the cold would be the return from the floor, and the mixed is what you send into the the floor. If you do that you can turn the heat way up to maximum on your hot water heater and set the tempering valve to 130deg or whatever you want it

In our previous condo we had installed a GE water heater. We heated the floor with the water heater and use it for all days use. Showers bath and hot water on the faucets . We had this system operated for 11 years and sold the condo last year , with the system still running perfectly. The G.E. Water heater is 60 gallon tank and is warranted by G.E. for 12 Years. The cost of the tank was that time with tax around 1000 dollars Canadian. Floors,walls and ceiling was heavy insulated. Lots of windows etc. 36 % of walls are glass. New owner very satisfied.

Just rewatching this. In order to keep HOT water stored in the tank (ie 160°) put a mixing valve on the discharge side of the tank connecting the cool return. 160° in the tank 80° return and 110 leaving the mixing valve to the slab.

I want to do this in my shop. Before I put the floor down we tie wired the pex to the mesh. From the bottom of the hole, plastic sheet, 2” blue foam, steel mesh, and 20’ sticks of 3/4” rebar on 2’ centers. Then wired down the pex in 4 loops as designed by the supplier. The pex is 1/2” red barrier pex made for heating. It has an extra layer of plastic coating to prevent air penetration. I joined all 8 ends together in series with a gauge in-line and added15 pounds of pressure in the pex lines for a few days before the pour 4-5” concrete. Then left the pressure in the line until now. My biggest issue is where to put the water tank since the garage has a 2nd floor and the gas chimney is an issue. I considered tankless, or electric (but I only have 50 amps in the sub panel out there). So after seeing your setup, I’m convinced the best way to go is with a power exhaust through the side wall. Good video! Thanks for taking the time to put it up.

Great job Jordan. I like your system. I moved from Eastern Ontario recently to Vancouver Island and I would like to build a shop with a similar system although I may use solar PV to heat the water. I like your detailed and well-explained system components. Thanks.

Good explanation and setup. Yeah a couple of repositioning of parts ive learnt from other videos but it works. Good job

Great looking system. I think the circulator is supposed to be mounted with the plumbing running vertically to prevent cavitation from air bubbles that cannot get away. I could be wrong though, Even so, great system.

Very nice job, injoyed it .going with it.

Thanks for the info. Hello from Winnipeg.

This is brilliant. Nice job.

Hey good on ya bud Nice video I’m in South Eastern Ontario Glad to see some Canadian dollars figures associated with it

Nice simple system! Nice to see someone come up with a hydronic system that isn’t over done. I also live in southern Ontario and I’m wondering how your setup worked during the latest cold snap we had. What you have here is pretty much exactly what I have designed for my shop, so I’m curious. Only difference is that I picked up an actual boiler for mine after listening to “experts” tell me HWH’s won’t work Thanks man! Loved the vid!

A complete list of the hardware that you used would be greatly appreciated (pump, timer etc...)! I also live in Southern Ontario and will be building a garage soon. Just looking through some of the comments others have left and all I can say is Wow! So many haters! For what it's worth, I am a fan. Great job. Also an update on the health of your system would make a great video, maybe shut up a few people that think they know better.

Great job Tks for sharing

good job man , I wan do this at my house this same system, for last 2 years I been told by one of the contractors locally here that I can't and it won't work so I been looking on youtube and web to find something and idea on how to anyway long story short I am so glad found this video and I just call him again and told him I need to talk hi thinks that I will go with his idea but I am gonna show your video that is possible to go with this system, acutely its possible to do what I wan

Great vid! Thanks

Interesting about the relationship between the heater tank and circulation. Never thought before that if the tank runs out it may try to heat the "water" forever which blows the efficiency in the trash. Something to think about.

Damn good job and very helpful!

Great video man

Good Video! I'm a Red Seal/Master Electrician as well and Red Seal HVACR Tech. You have built a great system and perfect for your shop like you said. All looks and works as you want. The one thing I noticed was you didn't have a maid"O"mist/air bleed on the high point of your system. You may have added one already, but could easily be installed on the return globe valve before the pump. Thanks for the video great work!!

I’m a electrical fitter in Australia and most of my fittings are missing face plates too🤔 I probably wouldn’t stress too much about what people say about the use of a hot water system, there will always be people that aren’t happy. I’d like to give solar hot water system a go. Here in Australia at the absolute coldest it would only get to 1-5 degrees C and that’s only for a few days a year. I just want a system to make it more comfortable for all year round use. (No excuses to finish those jobs in the shed😉)

Great video!

I have a similar set up in my detached garage in Minnesota and my water heater lasted 20 years.

Thanks for your input.

Very nice set up! I really like that you are in Ontario aswell... Hate when i see ideas, but they are being used alot more south then us. Makes you second guess if it would work here or not.

A hot water heater will last far longer in a closed loop hydronic system , especially with glycol, then used as a regular water heater. It's way better then a boiler, if your space is small and insulated enough. Just check your anode rod every couple years. The only thing I like to do is keep the pump a little lower because of air pockets. Nice clean install.

Just and FYI, air always finds it way to the highest point of your system, you should have you auto bleeder at the highest point of the system. I have worked with large hydronic systems were engineers have made this same mistake. So do not feel bad.

Everything I've read so far prefers the hot water heater systems over boilers - said to be significantly more efficient and WAY less expensive up front.

Good job The exhaust motor on that Hot water tank may have a port to connect a 3/8 th drain tube line with a p trap ( loop in the line ) To drain condensation water out of the exhaust motor , I could be wrong but I see the ports with yellow caps on your tank , Just trying to help I’m not an expert

My energy guru says that a hybrid water heater is cheaper to heat your floors than gas or oil. Depending on the homes heat loss will determing if you need a storage tank to make up the slower recovery time with hybrid vs gas.

I love some of your comments in the video and the overall system is awesome. What spacing are the tubes in the slab? Is that 1/2" or 3/4" pex in the slab? Again, great video and thanks for sharing.

thanks for sharing. do you have experience with these systems or was this your first time doing this sort of thing? what knowledge did you reference when designing this system?

Hey great video and set up. Im trying to do the same for my detached garage that is just over 600 square feet with 2 runs in the floor. First of all where did you get all the parts from? The pump. Expansion tank with that thing above it and the thermostat. I live in ontario as well about an hour north of toronto. I just bought a small 10 litre tank thinking that would be big enough but now im thinking other wise. Now with what Sir Lovey is saying about controlling the flow to get the return temp to 15 degrees lower could you not use an adjustable manifold?

Thanks.

JP - good informative video. Are you running the glycol through the hot water heater and through the closed loop system, or is water running through the hot water heater and there is a heat exchanger off camera that transfers the heat to glycol in the closed loop?

Great video. Could I email you with specifics questions? Thank you

Care to show the floor routing? How does it go in the floors?

Why a full cement slab floor vs. an integrated removable grate system that accesses to the pex tubing? You can wrap the pex in foam or narrow insulation batts into the grate channels. Maybe go further with some rubber removable tiles to cover the floor entirely? I understand the weight of what goes on the floor is a factor, but mixing the floor in rows of cement with alternating grates should disperse the focal points of weighted objects on to a larger surface floor area? Another function of these channels is 'if' you have a pex leak, the water can divert to the channels and not pool above ground. Just ensure you have an exit point on the flooring system going down hill and away from your structure.

Very impressive setup, and really helpful video. What is the BTU output of your water heater? I am considering a very similar system, however I need to use an electric heater (planned solar power in the future for my shop), and am trying to figure out the wattage heater I need. (30' x40' insulated shop w/16' ceilings)

Hi thanks for the video I very much enjoyed it.. One question I had was about the intermittent timer on the system. Why is that needed? My thinking is if the output of the waterheater is getting rather cold the waterheater will be running and the output will be warmer than the input. So it will be adding energy to the system. I'm thinking the timer just limits the heating capacity of the system.

What type and size of tubing did you run under the floor? My garage is only about 25p Sq ft, and we're building up a subfloor on top of the concrete. How many loops do you think I'll need under the floor? Thanks, this was one of the most helpful videos I've found in this. Thinking of going tankless for my project.

Thank you for the video. I wasn't quite understanding about how you avoided hitting any of the runs under the slab. Did you take measurements to know where you could punch into the concrete? Thank you for the reply in advance.

Low 60's in a garage is almost too warm if you're working. I prefer 55 or so if working in the garage. Now just sitting in a chair having a beer 65-70 is better. 😁

Other than a few code violations (I'm from the USA) the only major thing I would correct here is to get rid of the circulator timer as it serves no function. That's right, there no reason to shut down the circ as long as there's a call for heat. You will transfer more BTUs to the floor (even at lower water temp) with constant flow and cause less thermal cycling of the slab. BTUs delivered to the room will become a function of how long the burner runs. Since that's about 35,000 BTUs (based on heater size) then that's what you will get per hour no matter what the water temp is. You will probably find that lowering the heater temp down a bit might also be helpful. If there's a proper amount of pipe in the slab you should be able to heat the place with 100 - 110 degrees instead of 130 degrees. It will also be easier to maintain comfort in milder weather. The key to floor heat is to MAINTAIN temp. If you feel the urge to warm things faster you can always add a Modine style heater on another t-stat.

I live in Ontario as well. Nice low cost install. What pump Grundfos pump are you using? Where did you buy it?

Nice work , i am currently piecing together what i need to do a similar system in my 2400sqft shop , i have to use an electric hot water tank as i don't have natural gas hook up . Wondering if a electric hot water heater will be enough for my needs , I live on Vancouver Island so the coldest it gets is maybe -15c , I have been looking to size the circulation pump properly as well , the pump i am looking at is 8.5gpm. Would you add a mixing valve as mentioned in the comments? think it would be a benefit to my system ?

Best way for floor heat is to have a Floor Sensor to keep it from cooling down so much. Mine is Max Floor temp 20c. Room temp minimum 15c. Keep floor at 15c. Floor maxes at 20c so feet dont sweat however room could be lower temp with outside air (have makeup 240v Electric Heater for when garage door Opens to bring temp up faster, or if im working in there and chillier. Keep runs Under 200-150 Feet if possible. (foot runs are marked on the piping! Run outside perimeter on FIRST on runs, then back to manifold. Remember - Ball Valves are supposed to be ON OR OFF. Otherwise packing will wear over time. Hot water heat forever!!

Can you tell me the BTU rating of your water heater? I'm considering an electric water heater with solar pv panels.

Really nice setup, but you lost me at "tayco" I havent seen anyone go to a mexican restaurant and ordering a beef tayco with extra cheese 🤣😂 We have multiple of products from that company at work and everyone calls them Taco 🌮, we use their leak breakers and pumps, for every apartment, the pumps last 6+ years, the leak breakers we just started implementing, but so far, they work perfect 😎👍🏼

So one small logic mistake is shutting pump off. Just let the water heater run when heating up. The timer logic is wrong here. Just turn the water heater on and water heater will run continuously until slab is heated. Shutting off the water heater doesn’t save fuel. Either the water heater is big enough or not. 40k should heat slab. When you initially turn system on it will be cold and water heater will struggle shutting the water heater off in theory actually used more fuel. Let it “dump” and recover while recirculating.

Hey I did the same setup as you I'm not fully sure how to wire up the thermostat are you able to send me a picture

I really like this concept for the water heater, my question is the timer. Does the taco relay turn on the timer or the timer turn on the relay. These are 120v tank is 220 volts. Thanks again Gary

It seems like if you turned the temperature down on the water heater, then you could let the pump flow constantly rather than having to turn it on and off. Am I missing something?

Interesting that time out relay for 45 mins. every half hour to help tank heat back up before it starts circulating fluid again till you reach target temp then the whole system shuts down. Doesn't the floor cool back down after the 45 mins. kind of delaying the overall goal? I'm looking at installing a system like this in my basement and was considering an on demand hot water heater which would probably eliminate having to pause to reheat water. Do you have any data without that reheat option so as to compare costs between both?

Would a hybrid electric water heater 80 gallon work for this

Hey would you give me a complete list of material I’m about to put one in my 32x60 shop

Jordon, the Glycol you added to your system was it diluted at all or a 100%? Or should I ask can you run it as a mixture like 50/50 w H2O? Thanks and great video very helpful. I have everything together and will be installing before the winter hits here in MI.

Don’t you need balancing valves on the return manifold in order to have even temperature distribution throughout the space

Does this set up not require a header tank and a sight gauge?

Seeing there are lot of great comments here from others who have done this (and they are offering great advice and ideas) what I wonder is there a "forum" for in-floor system heating that I can join and learn from? If anyone knows of one please provide me a link -- Thanks

Has your tank held up over time. Could have done a condensing on-demand natural gas unit

Is the glycol in the tank? Thanks Gary

Thanks for sharing this video Jordan, I would to install a similar system, and to boot my Buddy has similar system and he is currently experiencing heat lost as the hot water tank is not big enough and runs out of hot water tank. Would you mind sharing what you used for Timer , relays, 24 v transformer and the layout of the configuration would be great. I would like to do the same thing and then help my buddy fix his fit up. Anything you can share would be greatly appreciated.

How's this system working 4 years on? I'm building a 1500 sf garage and planning something very similar. I have a very expensive on-demand NG boiler in a 10-year-old apartment building and it's already on its way out, so I will certainly be going with a HWT in my garage too lol.

Awesome video, thank you. Just curious, did you insulate underneath your concrete slab? I'm reading a lot of articles where concrete was poured directly onto 2 inch rigid foam insulation.

I wonder if you could just program a thermostat to run for 30 minutes, and then shut off for 30 minutes? If that seems to be what keeps your room comfortable, why worry about a temperature control. You could just turn down the temp of the water heater when the weather starts to warm up a bit. That would eliminate the need for the "override" timer. Just a thought.

Great video! Very helpful. A couple of question if you don’t mind. What diameter of PEX in the floor and portion beyond the manifolds? Also, what size pipe is that you used at the water heater?

good video; would have been easier to view/follow your implementation with less confusion if whole system was presented with some kind of plumbing diagram. Designing and installing a radiant heating system for an optimal performance is not for typical youtube viewers.

What size is your water heater? Gallons ad but? I'm heating a 1300 sf building in Montana with a 40 gallon 35000 btu water heater and it seems to cycle too often. I'm guessing I need more but in order to keep up better. Also, is there a chance that it would be cheaper with a bigger heater? If it can keep up better its may be more efficient?

were there any issues with the staples pulling out of the foam when the concrete was poured? Getting ready to build a garage here in a few weeks and i'm thinking about fastening methods for the pex.

With your Rheem water heater, what BTU is the tank and size of the tank, gallon wise? And , may I ask, what’s and average monthly power bill between Dec. and Feb.? I’m trying to figure which water tank to buy and Rheem has been in our choice list. Great video and thanks!!