Radiant heat question

Re: Radiant heat question

PostBy: Scottscoaled On: Tue Jan 17, 2012 12:07 am

I was looking for the supply and return from the boiler. But yes, the flow should be away from the mixing valve. The valve next to the mixing valve should be open to allow the cooler, allready mixed water to flow back to the boiler. I don't see the path. ;)
Stoker Coal Boiler: EFM 520, 700, Van Wert 800 GJ 61,53
Baseburners & Antiques: Magic Stewart 16, times 2!
Coal Size/Type: Lots of buck
Other Heating: Slant Fin electric boiler backup

Re: Radiant heat question

PostBy: LsFarm On: Tue Jan 17, 2012 12:57 am

I'm using a 15-58 3 speed pump on low to circulate hot water through 6 x 300' loops of 1/2" pex.. unless the pipes are plugged somehow, then the pump is adequate. This is in my house.

In the shop, I'm using a Taco 007 to circulate water through 800' of 3/4' plastic pipe.

The next pump up from the Taco 007 is a 0011, for the red pumps, Grundfoss, the next one up that is equivalent to the Taco 0011 is the 26-96.

I'd gut that mixing valve, and check the flow on each loop in the floor. And check how it works then.

Greg L
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Radiant heat question

PostBy: CapeCoaler On: Tue Jan 17, 2012 1:00 am

Where is the other manifold...
Is just valves, maybe a squished fitting, another mixing valve?
Check the entire path for other issues...
There may be other issuse based on what we see here... ;)
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Re: Radiant heat question

PostBy: Ops164 On: Tue Jan 17, 2012 3:13 am

This sounds like a flow problem to me as well. I've worked on a couple of radiant problem jobs, and one thing yo can do is close the return valve, leave the supply valve open and open the drain valve to see how long it takes to get hot water thru the system.

With 180* going out and 80* coming back you should be able the feel the floor with your hand and find the choke point. If the entire floor is cool I'd think it'd be something running bassackwards...

Stove/Furnace Make: Harmon
Stove/Furnace Model: Mk III

Re: Radiant heat question

PostBy: chevymatt On: Tue Jan 17, 2012 7:47 pm

Well thanks to everyone here I think I've got the biggest problems solved. The circ pump was def feeding opposite than it should be. I took the pump off and checked to make sure the propeller was working and not jammed up. I then rotated it 180* so the pump is now feeding the 1" Pex and coming back in the 1/2" Pex. I turned 3 of the 4 returns off and bled the system till I got warm water back out. I still need to replace the mixing valve but hopefully my garage/ apartment won't freeze up and break pipes again. Thanks again everyone
Stoker Coal Boiler: AHS S260