Tankless Heater (Radiant Heat Floor) recommend using this setup

[fir3ma5t3r]

As you see only the tankless heater temp control is there. (NEVER put the thermostat close to the hydronic system as it gets hotter unlikely the room temperature. I've seen a lot of people using boiler hydronic setup with the tankless which makes a short life on the tankless heater.


See how I followed the heatlink hydronic diagram for the tankless heater and I ended up paying $35 a month on NG leaving the supply temp at 110 and the return temp at 90-95 24/7 and I get around 70-75F in 30x22 shop with 2" insulated floors. I havent installed the outdoor reset just yet...trying to get it done this weekend hopefully.. Will keep you guys posted.















Even tho I'm new to this forum I took all my time doing a lot of research on the radiant heat floor so far the tankless heater has proven me its more efficient and remember the effectiveness of the system is dependant on the system being designed and installed correctly. Proper consideration of factors such as BTU loads, outdoor design temperature, indoor design temperature, room set-point temperature. ONce these factors have been considered and the system requirements determined then you'll be happy with the tankless heater

 

[tomroblee]

That looks like an interesting setup. I'm curious about a couple of things.

Where are you located? (I'm curious about the climate).

How often and long does your tankless heater run? (If your gas bill is only $35 per month, I guessing that the 70,000 btu heater can't be running more than a couple of hours a day. I'm just curious whether it runs a couple of minutes every hour or for a longer period of time every several hours.)

 

[tdkkart]

I get around 70-75F in 30x22

You workin in your skivvies or just sittin' out there watchin TV??
My shops floor heat is set at 55*, why is plenty warm if I'm actually working.

 

[83trekker]

Yes please more details on your setup. Thanks

 

[ketas47]

I have nearly the same tankless water heater ,navien 210a 17000- 18000 btu. 98 percent eff.(For infloor heat) I have a 26x38ft garage, 2x6 walls 2 10x8 doors and 1 service door and 3 windows insulated very well. It runs 1-1 1/2 hours maybe 1-2 times a day (20-30F degrees outside). Lately it been around 0 so it run 2-3 times a day.I keep it around 58 degrees F and is very very comfortable.My last bill(natural gas and electric) for my 2 story house and garage was $250. I think the garage is costing me about $40 to heat . I also have a heat exchanger hooked up to the water heater (I can turn the heater up to 140F when I use the heat exchanger)if I want to raise the temp faster for gatherings, nice option. Normally I set the water temp @ 110 with a return of about 85. I love the set-up that I have!!!! I went this route mainly from reading about similiar systems on Gj!!!! Installed everything myself from info from this site. Thanks for all the input GJ members. PS I started up system in Dec. so not alot of history yet. I live in Central Wis

 

[Dick in Wisconsin]

I live in Central Wis

I live in Grafton, so my experience should be as good or better than yours. Building 25x40 (1,000sf) in the spring. Have a surplus residential water heater to start out with. thanks for the information.

 

[fir3ma5t3r]

You workin in your skivvies or just sittin' out there watchin TV??
My shops floor heat is set at 55*, why is plenty warm if I'm actually working.

LOL, yeah just running 70F for another week to finish epoxy floor....I'm still new to my shop as its only 4 months old..

 

[fir3ma5t3r]

That looks like an interesting setup. I'm curious about a couple of things.

Where are you located? (I'm curious about the climate).

How often and long does your tankless heater run? (If your gas bill is only $35 per month, I guessing that the 70,000 btu heater can't be running more than a couple of hours a day. I'm just curious whether it runs a couple of minutes every hour or for a longer period of time every several hours.)

From Ontario & it runs 10-12 minutes every 3 hours if I keep opening door not sure how often it runs yet still new to this setup I built. Not sure if this has anything to do with foam insulation too as its sprayed full in foam insulation.(walls/ceilling and rim joinsts). Hate to say this but my walls are R6 and ceiling at R24 I find them to be good ENOUGH when it comes to foam product as it seals 100% and I keep my ceiling open (no drywall) as foam holds heat better then drywall from my experience as I did some test between two and notice drywall is colder probably cause I havent painted it yet??? still trying to figure out why........will upload shop pics soon so you guys get idea on the radiant heat floor

 

[fir3ma5t3r]

I live in Grafton, so my experience should be as good or better than yours. Building 25x40 (1,000sf) in the spring. Have a surplus residential water heater to start out with. thanks for the information.

NP... believe me this setup kicks in the *** as it was designed to work better with tankless heater as I see how it runs its too sickie.. I dont believe in using water heater and boiler setup on the tankless heater and its not really recommended but people did it.... hope they r happy with it though

 

[KPSquared]

How much did that setup cost?

 

[ketas47]

I see your running 2 pumps,Why? I have same tankless water heater and only 1 pump, Am I missing something?

 

[fir3ma5t3r]

how much did that setup cost?

$600.00

 

[fir3ma5t3r]

I see your running 2 pumps,Why? I have same tankless water heater and only 1 pump, Am I missing something?

One pump is for 3 ways mixing valve to go to supply (in floor) and automatically regulate the water temperature in the secondary circuit. You do need TWO pumps when it comes to tankless heater...

 

[KPSquared]

$600.00

For everything in that pic? I didn't even think you could get a decent heater for that.

 

[Rickcnc]

For everything in that pic? I didn't even think you could get a decent heater for that.

I'm interested on more detail as to where you sourced the material.

I had someone quote a condensing boiler installation, (I have the header and pex installed) the quote came in at $7400.00

 

[KPSquared]

I'm interested on more detail as to where you sourced the material.

I had someone quote a condensing boiler installation, (I have the header and pex installed) the quote came in at $7400.00

That's about the pricing I got as well. $7000 - $9000 just for basically what you see on the wall in that pic. . .

 

[fir3ma5t3r]

For everything in that pic? I didn't even think you could get a decent heater for that.

without tankless yeah $600.00 air seperator is $100, mixing valve $40, astro 30 pump $20 off kijiji and the 26-99 $250 plus fittings etc......

 

[fir3ma5t3r]

I'm interested on more detail as to where you sourced the material.

I had someone quote a condensing boiler installation, (I have the header and pex installed) the quote came in at $7400.00

your better off doing it yourself!!!

 

[tdkkart]

without tankless yeah $600.00 air seperator is $100, mixing valve $40, astro 30 pump $20 off kijiji and the 26-99 $250 plus fittings etc......

But what does the heater cost??
Some are quoting ridiculous prices for systems, what if you have an operating system, what the new boiler cost in the box??

 

[ketas47]

I am curious why you say you NEED 2 pumps.I have the Navien 210A on demand condensing water heater (Looks alot like yours but older, mine 2009 model)and I only use 1 pump and no mixing valves. The temp going infloor is 110*F and returning to WH is 80*F.,which is good temps for floor and heater,also pretty good Delta T. A very experienced infloor heat plumber recommended this set-up. The only thing I see different to other of on demand brands and the navien is i have a bigger pump. The plumber said I need the bigger pump (Stiebel Eltron,model cp3s26-110fc 1/6 H.P. 3 speed) because of the high head pressure on the Navien. My system is very simple and very eff. Also my system runs about 1 hour once every 15 hours,depending on outside temp. This longer run time is suppose to be better for heater,instead of short cycling. Ps Also looked @ 2 locally installed infloor systems and they also use 1 pump and no mixing valves.(they used Rinnia on demand WH) The reason I went with Navien is it is about 95-97 eff. and I bought it used(2yrs old) for $400 and am very satisfied with it so far!!!!

 

[fir3ma5t3r]

But what does the heater cost??
Some are quoting ridiculous prices for systems, what if you have an operating system, what the new boiler cost in the box??

Yeah.... got mine (NR-180A) off kijiji for $600... I think its priced at 1400 right now

 

[ponjohn]

Are you guys running public or well water?

I was told by several people that well water destroys the tankless heaters. You have to have them flushed once a year at 150-200 per.

I am looking adding radiant floor heat to my basement and under joist for main level ( ranch home).

 

[tdkkart]

Are you guys running public or well water?
I was told by several people that well water destroys the tankless heaters. You have to have them flushed once a year at 150-200 per.
I am looking adding radiant floor heat to my basement and under joist for main level ( ranch home).

Filling you system with distilled water should eliminate problems with scaling and corrosion inside your system.

 

[ketas47]

I used distilled water.

 

[ponjohn]

Where do you get 50 gallons of distilled water? (LOL)

 

[tdkkart]

Where do you get 50 gallons of distilled water? (LOL)

I bought 15 gallons one nite at Wally world, they had 50 available if I would have needed it.
It's like $1.19/gal, cheaper than gasoline.

Put 10 gallons on the wife's grocery list 5 weeks in a row, if she loves you she'll get it for you.

I took a clean 5 gallon bucket, drilled/threaded a hose barb in the side near the bottom and hook s piece of washing machine hose to it, which then hooked to little 110V Simer pump, and then another washer hose to the heat manifold.

Fill 'er up!!

 

[ketas47]

I was told that the water that comes out of a dehumidifier is considered distilled water, another option instead of buying it.(If this is true. I am sure someone will correct me if Im wrong.)

 

[Highbeam]

I was told that the water that comes out of a dehumidifier is considered distilled water, another option instead of buying it.(If this is true. I am sure someone will correct me if Im wrong.)

Not the same. The dehumidifier water is indeer water that was once a vapor in the air but while being condensed it was in contact with dust, pollen, and other junk floating around in the air. The water will be quite dirty.

 

[wedge40]

Where do you get 50 gallons of distilled water? (LOL)

If you're using a tankless heater and 1/2" pex you will need about 1 gal per 100' of hose.

Wedge

 

[NCtim]

Are you guys running public or well water?

I was told by several people that well water destroys the tankless heaters. You have to have them flushed once a year at 150-200 per.

I am looking adding radiant floor heat to my basement and under joist for main level ( ranch home).

I'd get a Freshstart prefilter from a hot tub or pool place online. Mine cost about $85 and is good for 10,000 gallons. I use it to fill the hot tub and will use it for my radiant heat. Hooks to the hose and filters everything out of the water.

 

[Fastback]

FWIW RV anti freeze is made with clean water and is not much more than water in the springtime, (and it also lubes) just sayin.