Floor heat question

[Dirt Buster]

For one of my self serve bays the radiant floor heat system has struggled the last couple winters due to a small leak underground that we have been unable to find. To combat this - we put a 15 gallon tank in our attic with a float to fill up the tank more if the fluid runs low. But with the system no longer being pressurized the taco pump 0011-F4 wasn’t getting enough flow to fire up the system well. So I installed a small transfer pump right after the 15 gallon tank to supply some pressure to the taco pump which is 20-25 feet away. That worked but the transfer pumps are not lasting. And I know they are meant for continuous use. Does anyone have any recommendations on which pump to use right after the 15 gallon tank? Can a taco pump run on just a gravity feed? I’m thinking to put a 007 taco right after the tank instead of the transfer pump but not sure if it will work

 

[PaulLovesJamie]

I know this isnt an answer to what you asked, but I used a slightly different solution to the same problem - I plumbed in an automatic fill valve. That valve adds water as needed, its purpose is to keep the system full at my specified pressure.
Note that my leak was slow, I was only manually adding water a gallon per day or so. Idk how much leakeage these valve can compensate for, but I imagine its a lot more than a 15 gal tank.
Less than $100 bucks when I did it, took me longer to figure out which one to order than it did to install. OK, thinking, probably more than $100 because I isolated it with ball valves, and iirc I put a small backflow prevention on it to guarantee the glycol couldnt backfeed. Still simple though.

edit: this isnt the one I used (dont recall the specifics), but heres an example, $97. The description says: "The 5350 series AutoFill automatic filling valve is a pressure reducing valve which when installed on the water inlet piping in closed hydronic systems will maintain system pressure at a set value, automatically filling up with water as required."

 

[Eric H]

Fast fill valve and a backflow preventer before the fill is the proper way

 

[Dirt Buster]

I know this isnt an answer to what you asked, but I used a slightly different solution to the same problem - I plumbed in an automatic fill valve. That valve adds water as needed, its purpose is to keep the system full at my specified pressure.
Note that my leak was slow, I was only manually adding water a gallon per day or so. Idk how much leakeage these valve can compensate for, but I imagine its a lot more than a 15 gal tank.
Less than $100 bucks when I did it, took me longer to figure out which one to order than it did to install. OK, thinking, probably more than $100 because I isolated it with ball valves, and iirc I put a small backflow prevention on it to guarantee the glycol couldnt backfeed. Still simple though.

edit: this isnt the one I used (dont recall the specifics), but heres an example, $97. The description says: "The 5350 series AutoFill automatic filling valve is a pressure reducing valve which when installed on the water inlet piping in closed hydronic systems will maintain system pressure at a set value, automatically filling up with water as required."

I appreciate the advice! I'll definitely look into this. My leak seems to sometimes be sporadic, but it is there for sure. I thought if I kept the system at a specific pressure then it was more likely to leak quicker vs. a low/non pressurized system. But I will look into this

 

[Dirt Buster]

Fast fill valve and a backflow preventer before the fill is the proper way
View attachment 12352 View attachment 12353

Thank you for the pictures and advice! I appreciate it

 

[Gary D]

I just wanted to chime in on this we had a leak that was like your and we used this stop leak and it worked!!

Amazon.com: Fix-A-Leak by Marlig for Swimming Pool Spa Hot Tub Leaks 32 oz,White

It is thick so stick the bottle in hot water for 15 mins before adding it to the boiler let the pump circulate with heat going for 6-8 hours turn off the heat and run 6-8 more hours with just the pump let it sit off for 24 hours to allow it to settle into the leak areas Then drain the system and refill with fresh water and glycol or antifreeze Worked like that for us and has been ok for the last month.
PS: If you have a large layout ( more than 4 bays) use two quarts

 

[washnvac]

To add to what Gary said..... I used that product at a location with a small leak. I did exactly what the bottle said. I poured two whole bottles in my expansion tank, and ran the circulator for 48 hours, with no heat. Then system off.

Then when floor heat season came around, I just turned the heater on as normal. I did not drain system at all. Product worked like a charm, to my amazement. 12 years, no issues.