Troubleshooting floor heat

[Tpoppa]

I just replaced the bearing assembly on the circulator pump on my floor heat system. The seal in the bearing assembly developed a steady leak that lost at least 2 gallons of antifreeze. I probably lost another 1.5 gallons of antifreeze when I pulled the pump. I do not know how much antifreeze is in the entire system.

I refilled it to a level that looked right and let it run for 2 days. The level dropped over those 2 days. I'm sure that was partly due to air in the system and antifreeze moving into the elevated expansion tank.

I there a more scientific way to determine the amount of antifreeze to fill a floor heat system? Should you fill when warm or cold? Any advice is appreciated.

 

[dogwasher]

You would have to get a idea of how many feet of tubing was laid out under the floor and the size of the tube, then you could get a good figure on how much the system takes. If you have the original drawings and come up with those figures I can tell you how much glycol you have in the system.
I would fill it up again and see where it is tomorrow to see if you have another leak. How are you checking the level? Do you have a torpedo styles fill tank with sight glass mounted high above the boiler?

 

[car washing systems inc]

If you have an tank with a sight glass mounted on the side of the heater, turn the pump on without the heater on. You should have a mark on the sight glass fill to the line, put the cap on the tank start the heater.

 

[Tpoppa]

I don't believe there is any sight glass.

The only way I can check the level is on the highest horizontal pipe in the system. There is a gate valve that I can open to visually inspect the level. When I open the gate valve it usually releases a bit of pressurized air. btw, my system usually runs around 5psi.

 

[2Biz]

My boiler has a vertical fill pipe right at the pump inlet and I had the same issue as you. I couldn't tell if the system was low or not. One of the guys here on the forum advised me to do this and it worked great.

I extended the fill pipe (2.0") with PVC about 2 feet. I attached a clear pvc line to the outside of the 2.0" pipe by drilling and tapping the pipe and by attaching elbows and barb fittings. I also put a ball valve on top with another clear pvc hose coming off that. With the pump running, put the hose in a gallon jug of antifreeze, and it will draw antifreeze into the sytem...And since I have lines running in the trough, this is the easiest way to fill the system without making a mess. The line on the outside shows me at a glance that the system has antifreeze in it. I don't know if this will work for you, but it worked perfectly for me.

 

[robtl]

I just replaced the bearing assembly on the circulator pump on my floor heat system. The seal in the bearing assembly developed a steady leak that lost at least 2 gallons of antifreeze. I probably lost another 1.5 gallons of antifreeze when I pulled the pump. I do not know how much antifreeze is in the entire system.

I refilled it to a level that looked right and let it run for 2 days. The level dropped over those 2 days. I'm sure that was partly due to air in the system and antifreeze moving into the elevated expansion tank.

I there a more scientific way to determine the amount of antifreeze to fill a floor heat system? Should you fill when warm or cold? Any advice is appreciated.

Give us more info on the "elevated expansion tank" is it a bladder tank or steel horizonal tank at the highest point......the expansion tank should never be filled with just system liquid, it should have a coushion of air at the top half to two thirds trapped there.
Also how are you filling the system?

 

[Tpoppa]

Give us more info on the "elevated expansion tank" is it a bladder tank or steel horizonal tank at the highest point......the expansion tank should never be filled with just system liquid, it should have a coushion of air at the top half to two thirds trapped there.
Also how are you filling the system?

The expansion tank is a bladder tank (I believe) that is located above the rest of the system.

I am filling it through a vertical fill tube that is at the highest point of the system. I know some air was trapped in the system when I pulled the pump. I am still seeing some bubbles coming up through the vertical fill tube.

I have been slowly topping it off each day with a few ounces. I guess it's possible that there is a leak somewhere else in the system, but I really don't think that is the case.

Is there a good way to purge air? Is there such a thing as overfilling?

 

[robtl]

The expansion tank is a bladder tank (I believe) that is located above the rest of the system.

I am filling it through a vertical fill tube that is at the highest point of the system. I know some air was trapped in the system when I pulled the pump. I am still seeing some bubbles coming up through the vertical fill tube.

I have been slowly topping it off each day with a few ounces. I guess it's possible that there is a leak somewhere else in the system, but I really don't think that is the case.

Is there a good way to purge air? Is there such a thing as overfilling?

OK if the expansion is a bladder tank not to much worry about overfilling,,,,,Like i said before there needs to be air trapped in the top portion of the regular tank if it is a closed system.
Topping off the system with antifreeze thru the vertical fil tube is ok and running the system circulating the water will vent the air to the high point and can be released by hand over time after running awhile.
To make sure the expansion tank is a bladder tank there should be a sniffer valve (tire tube valve) made in the shell somewhere.
good luck,

 

[2Biz]

A pic of the fill tube and sight gage I made. You can see the coolant is about 2" from the top of the tubing. Quite easy to make...

 

[dogwasher]

Not sure if I need to re read this but did we figure out if this is a expansion tank or a Bladder tank?(Or called a Extro tank)
Can you supply some pictures?
If this system is piped correctly(probably not..) there should be a air scoop piped in. If its a expansion tank it may be piped so the air bubbles rise up into this tank.
I understand your explanation of the vertical line with a tee so you can open the line and top it off but normally you should have some sort of holding/fill tank with sight glass all mounted up a bit higher than the boiler..this tank would also act as your expansion tank.

 

[dogwasher]

great a picture I will take a look

 

[dogwasher]

A pic of the fill tube and sight gage I made. You can see the coolant is about 2" from the top of the tubing. Quite easy to make...

Great idea Tbiz. I like that idea, especially if the forum member change the PVC to 4" and then raise it up a few feet.

 

[Tpoppa]

Update on this: My floor heat system is working really well. Refilling was a PITA with lots of trail an air adding small amounts of glycol and purging air. 8oz seemed to make a difference between not enough and too full.

 

[Earl Weiss]

Did something similar for my trough heat. Simply put a 1/2 in valve at the top of the fill tube and then above that Bushed it up to 4" Easy to pour in that way.