Radiant design question

ALH_3

It sounds as if a check valve may be stuck open or not there at all. What about the DHW recirculation line?..if there is one. As soon as the heating system pulls the water heater down does it switch back to DHW production and heat it up? bouncing back and forth from heat to DHW Any possibility of a schematic drawing?

Turning the water heater temperature up isnt really a solution as it doesnt really address the problem of the tank losing heat to the system. Turning the temperature up also increases heat loss during standby and makes the boiler work harder to satisfy the tank.

-Andrew

Phil Yarbrough

Radiant/DHW problem

Hi all.
I ran across a radiant system heating a basement with a 75 gal water heater. It serves domestic water and tied to radiant with a heat exchanger.
The problem is when unit is heating the radiant, the water temperature in the tank drops enough that domestic water isn't hot enough for showers and such.
I've been assigned the task of solveing the problem. My first thought was to turn up the temperature on the tank as high as it will go and add a tempering valve to the domestic side. I would appreciate any ideas.

Phil Yarbrough

Flow

Thx for the reply. I'm includeing a hastily put together diagram. The raidiant is controled by a relay that turns on the pumps. No check valves, no DHW recirculate. Just an aquastat to turn off source pump at 120 degrees.

I assume whats happening is that starting with 130 degree water, The radiant is pulling tank temperature down to uncomfortable level for Domestic use. and recovery isn't quick enough to compensate.

Any further ideas will be greatly appreciated.

Thx again Phil


--------------------------------------------------------------------------------

Nron_9

add a three way thermsotatic valve to the radiant side it will slow down your heat transfer and help prevent temp swings