Radiant floor needs upgrade

[Johnnys Shop]

this set up was built in 2008 (fall)
I was going to use a tankless water heater.

Plumber talked me into going with this high efficiency 151 litre tank. Both are for propane

Well the water heater has started leaking. last spring the Pump burned out from no water. The air release cap on top ( silver cups forget their name) came off and water oozed out. this happened through out the winter. no where near consistent enough for it to be a leak in the pipes. because it could be weeks or even months then it would need about a litre or two. other times half a litre. I would fill up the black pipe and run the pump till the water level stopped going down.

so in short I did not like the system it was expensive to run. The water heater would run 2-3 hours a day the pump would run every 2-3 days or longer. The heater would sometimes run for long long times to try and keep up with the pump. you needed to keep the water at max all the time for this system to work. he did say he put the pump on the wrong side or wrong direction something like that. The pump runs cold water into the heater. by the expansion tank. there was glycol in it. but i guess over the years it was diluted or maybe there was not enough to start with.

Hopefully that all makes sense I am on medication so the brain is not always firing on all cylinders.
I have severe arthritis and without the radiant floor heating I am pretty much useless that form of heat allows me to work and I need to get it going again.

 

[Johnnys Shop]

Is anybody able to help me. I pumped out the tank. it started really peeing all over the floor as i was pumping it out. lots of light blue and brown rocks came out and were easily crushed like powder. I am guessing from the water heater corroding.

I live in central Alberta Canada. shop is 624 square feet. it has a vapour barrier below then 2 inch insulation. the pad is overkill 8-10 inches deep on sides and 6 in the center. one hair line crack near the front where the door is most of the time it is impossible to see.

 

[Sureshot]

Not sure what help you want but I think you need a mixing valve so the water heater can stay up at temp, you need a low level cutout so the system shuts off if the level goes low or the pressure drops, and you need to figure out where the pump will work the best.

Do you run this all the time or just when in the building?

Is the thermostat on air temp, slab temp or water temp?

You also need to find out about the glycol. I would have thought a water heater would last forever with proper fluid.

 

[BadgerBoilerMN]

The problems you are having are 100% design/installation related. A "tankless" water heater is only as good as the designer and he will have to be good to make a tankless work.

Does this unit heat space and DWH?

 

[Johnnys Shop]

Not sure what help you want but I think you need a mixing valve so the water heater can stay up at temp, you need a low level cutout so the system shuts off if the level goes low or the pressure drops, and you need to figure out where the pump will work the best.

Do you run this all the time or just when in the building?

Is the thermostat on air temp, slab temp or water temp?

You also need to find out about the glycol. I would have thought a water heater would last forever with proper fluid.

Thank you Sureshot.
there is no mixing valve, no low level cutout, this runs all the time This is my work shop.

The thermostat is air temp which I did not think was the best.

I do not remember or have the jug the glycol came from. I would of thought the water heater would of lasted a lot longer then it did.

 

[Johnnys Shop]

The problems you are having are 100% design/installation related. A "tankless" water heater is only as good as the designer and he will have to be good to make a tankless work.

Does this unit heat space and DWH?

Thank you I thought i was a ill equipped design. This unit only heats the slab. there is no water supply going to my shop. I wish there was but there is not.

 

[BadgerBoilerMN]

Do you have a heat load for the space?

How big is it?

 

[Johnnys Shop]

Heat load?
space is 24x26 feet
i only heat during the fall till spring. it would of been the last few days here till about may

 

[jlckmj]

It is hard to tell from your pictures if the piping is correct on your water heater. I have a similar set up to yours and it works very well. You can see it in the following post somewhere.
Look through the link and read the descriptions of the various set ups, and you will start to get an ideal of what will work and what will work better. If that does not answer your questions, do a search on radiant heat here on the board and you will have hours if not days of reading ahead of you. Good luck

http://www.garagejournal.com/forum/showthread.php?t=49557

Jim

 

[Johnnys Shop]

okay well plumber came out today
here is what is wrong with my current system
a) its a water heater in our climate thats a no no. probably caused to much condensation and the whole tank is rusted out.
b) do not use distilled water, no sure why but it causes problems
c) It is possible the pump was flowing the wrong way so where the hot water should of been exiting the cold water was entering.
D) was not under pressure just atmospheric

Solution
115,000 btu boiler, a air separator and pressure gauges, and more glycol then what was in originally.

cost of original installation not including pex. 2400 cost to hire a better company to fix problems and do it right the first time 4000. potential savings a year in excess of 1000 dollars.

Getting back to work while having severe arthritis.... Priceless

it could potentially take my 2x300 gal tanks a year down to maybe 1/4 or perhaps even less.

 

[Sureshot]

Sounds like you found someone knowledgeable. Good Luck.

Where in central Alberta do you call home?

 

[HoosierBuddy]

So...do I understand this correctly:

- The first unit did not have make up water?

- The second won't either?

Phil

 

[Highbeam]

So...do I understand this correctly:

- The first unit did not have make up water?

- The second won't either?

Phil

It seems that most systems do not have make up water.

 

[Sureshot]

I have run for 13 yrs without makeup water. I pressurize the system enough to get it to fire and then wait until up to temp and top up the pressure if necessary. If pressure up before firing the expansion tank doesn't have the capacity and the pressure relief will let fluid go.

If you have no leaks why do you need it continually topped up?

 

[Johnnys Shop]

I live out by Rocky Mountain House.

He is going to put in a oversized Expansion tank. Which helps on closed systems. so i am told

I needed to top it up because the air release caps were coming undone and would ooze water. before those started going never needed it. and the tank was rusting out.
I asked about putting in another pressure gauge so i can monitor it better.

 

[HoosierBuddy]

I have run for 13 yrs without makeup water. I pressurize the system enough to get it to fire and then wait until up to temp and top up the pressure if necessary. If pressure up before firing the expansion tank doesn't have the capacity and the pressure relief will let fluid go.

If you have no leaks why do you need it continually topped up?

You have to have some sort of plan when it does leak.

That's like saying "Why does it need a TP valve" if the temperature and pressure are fine?"

Phil

 

[Highbeam]

If it leaks and you lose pressure, then you add more water.

 

[Rookie2]

what type of glycol ? why is the leak from the air bleeder white ?
you have to use boiler rated glycol ! I have a home built 40'x60' with a 175000 btu gas boiler, distilled water with 50% glycol and i top it off once a year and no city water.(50% GLYCOL IS even too strong for pumping and transferring heat)

Also did you use an oxygen barrier type pex ? if not your system will take air in thru the pex tubing and mix air into you water/coolant.

how would a water heater sitting on a heated floor rust from condensation ?

Thats all i can think of, my system has been up and running for over ten years.

Good Luck !

 

[Sureshot]

I very rarely have to bump the pressure. Usually on start up as it has lost the pressure due to cooling down. I monitor the pressure all the time and if it is down at all and I am going away for an extended time I will bump it as a precaution.

I use a Red Lion effluent pump so it will not overpressure the system. I have the pump rigged with sediment valves and wash machine hoses. I also keep 50/50 glycol on hand. I do have two boilers to look after. I have been thinking of adding a filter system so I could circ the system fast and filter the glycol. Not sure if it is worth it though. Should have had it the first year or chased everything with raw water and air before filling.

 

[Highbeam]

how would a water heater sitting on a heated floor rust from condensation ?

!

Gas water heater. Products of combustion are water and co2. Water in the exhaust is steam and when that steam hits the cold heat exchanger it condenses. So lots of water will condense on the exhaust side of the heat exchanger in a water heater set to floor heat temps.

Now, it's not just water condensing. Water with all that co2 makes a nice batch of carbonic acid. The acidity of this condensate will eat the mild steel water heater fast and cause a leak. Before the leak shows up as water, there is a good chance that the corroding steel will cause the burner to burn dirty and make lots of nice carbon monoxide.

 

[Rookie2]

maybe he needs to raise the water temperature to 180 and cycle the circulator pump with a thermostat. I heat 2400 sq ft by operating my boiler twice a day for 1.5-2 hours each time.

 

[Sureshot]

I would run the water heater at temp and use a mixing valve.

 

[Johnnys Shop]

I ran the water heater at top heat. no temperature on it just set it to Hot.
not sure what the glycol was. as he put it in. I will look into my pex piping, about the oxygen. that is the first i have heard about and something to check out.

 

[Rookie2]

Boiler antifreeze is the only antifreeze to use, car antifreeze in more than a 50% mix can turn acidic when in contact with high temperatures.

Wirsbo has a lot of information on design etc.

 

[Sureshot]

Given the Ops location he should be able to buy premixed pails of 50/50 glycol. Check with an oilfield chemical or mud supplier. I get mine from Prairie Mud and they have a shop in Lacombe. Many others in the area. Might want to phone ahead for price and they will mix what you want.

 

[chevelle64]

okay well plumber came out today
here is what is wrong with my current system
a) its a water heater in our climate thats a no no. probably caused to much condensation and the whole tank is rusted out.
b) do not use distilled water, no sure why but it causes problems
c) It is possible the pump was flowing the wrong way so where the hot water should of been exiting the cold water was entering.
D) was not under pressure just atmospheric

Solution
115,000 btu boiler, a air separator and pressure gauges, and more glycol then what was in originally.

cost of original installation not including pex. 2400 cost to hire a better company to fix problems and do it right the first time 4000. potential savings a year in excess of 1000 dollars.

Getting back to work while having severe arthritis.... Priceless

it could potentially take my 2x300 gal tanks a year down to maybe 1/4 or perhaps even less.

I am far from an expert, I did my own system with the help of Radiantec. What stands out to me is the need for 115,000 BTU. My garage is 26 X 32 X 14 and I've been heating it with a 30,000 BTU water heater for 5 years now with no problems. I keep it at 60 degrees all winter long. It seems to me that 115,000 is way overkill. Good luck with getting it all worked out .