Radiant floor heating problem

Dman

I have a closed loop radiant floor system that is tied to my existing hot water tank. It uses a heat exchanger. The floor is barely heating up and I think the source of the problem is the heat exchanger. It's a flatplate model fp3x8. The hot water enters one end of the heat exchanger and then is mixed with the return pipes of the radiant floor. The end of the heat exchanger that feeds the Supply pipes of the radiant is cold. I assume of the temperature of the pipe leaving the heat exchanger going to the supply pipes should be at least warm. The pumps are working as I can feel the water flowing. The water entering the heat exchanger is very hot. Do these heat exchangers fail? Are they easy to replace?

Jeffrey_Bruton

Last Time Working was....?

Dman:



You probably know your heat exchanger is a passive device (requires no power) and is a fairly simple component...so there is not a lot that can go wrong with it (no chance of electronic failure, power supply failure, etc.).



When was the last time it was working correctly?  Any noticeable events between then and now?



Is it a GEA brand?  If so what model is it (i.e. how many gpm is it rated for)?



Thanks

Jeffrey Bruton

Dman

Response

Thank you for the response. Yes I realize the heat exchanger is a passive device. It's a flat plate ( now GEA) device model fp3x8 , 8 gpm. The issue is intermittent , last night we got home and the floor was cold. This morning it is warming up. The only difference is I cranked the thermostat to 74 C ( I am in Canada) . I can feel warm water flowing through the pipes. Last night I could not feel that. The system definitely does not deliver the heat it used to. I also noticed the pump situated before the heat exchanger is corroded. But having said that when the system is on I can feel that pump working, when the problem persists I can feel that there is not any warm water leaving the heat exchanger side.



Do the heat exchangers plug up with rust/junk?

kcopp

Yes they do.....

Brazed/ flat plates are especially prone to that happening. How is your water quality? How big in the area heated? How big is the circ on the tubing side and what are the loop lengths?

Dman

More information

Water quality is very good. We live in a big city so it is well managed. Area is about 300 square feet , I do not know the loop lengths but the room is 28 x 11 feet and there are 3 loops. I did notice there is corrosion on the first pump just before the exchanger.



Thanks for your support.