Burnham 203 boiler error 24 at limit

JohnJay1

Hi there,

Can anyone help me. I recently piped a Burnham 204 boiler with primary/secondary.

Installed 3-way mixing valve.

Have a 15-58 pump on primary and a 26-99 on secondary. 6 zones total. 1" piping from boiler to manifolds. 1/2" infloor loops all existing.

Boiler seems to overheat and over shoot tripping an error 24 at setpoint of 165.

Can anyone point out issue here? Here is a pic of the boiler piping.

HVACNUT

That's not P/S piping. Why is it needed? Those circulators are pumping into each other. The "Boiler" circulator is probably just moving water through the boiler without picking up any system water. Repipe.

EBEBRATT-Ed

looks to me like the 3 way valve is bypassed with another pipe

JohnJay1

Please Help

JohnJay1

How is it not primary/secondary piping?

The boiler pump is pumping through the primary loop.

The system pump is pumping into the the radiant infloor manifolds pulling from the mixing valve coming off of the closely spaced tees?

How is the three way mixing valve bypassed?

How should I correct this ?

hot_rod

Is it piped like this? If so you do have a primary secondary. The boiler is within one loop, radiant via close tees.

Is there a second air purger that the expansion tank connects to? The secondary loop is the one with the expansion tank connected.

That looks like a Caleffi 521 valve, so that 26-99 should flow 5,6 or more gpm.

Looks like some radiant in the slab near the boiler? Are the upper zones in a slab also?

Both pumps turn on together? via a zone control? It sounds like maybe the boiler pump is shutting off and causing the over-shoot.