hi my name is mike and i want to put a taco sr 503 relay on my weil mclain cg hot water boiler i installed the relay ran the wires from the pumps to the rely and ran the therms to the relay and took the 120 v off the switch but what do i do with the old relay that was originaly wired to the controls ,the boiler will not go on unless i keep this old relay wired i have to tie the 2 wires together to make it work then it fires up and shuts off at 170 deg and turns back on when it goes below 140deg what did i do wrong ,the 2 wires that i tied together are the green and the red off the old relay thanks any input would help

 

Did you read the instructions? It's the first diagram on left on the first page.

http://www.taco-hvac.com/uploads/Fil...ry/102-167.pdf

 

hey thanks but the instruction sheet from taco is for 120 v to the aquastat and all other controls the controls on the boiler are 24 v

 

No, yer reading that wrong...

The X1 and X2 terminals on the relay panel are a 'contact closure' and they will make contact when the panel calls for heat.

Measure it with a multimeter if you don't believe it.

 

hey nj trooper
so what ur saying is the x1 x2 will just complete my circut but what about the wires in the harness to the damper they are all together wired in to the old relay thanks

 

When you say 'old relay' , I believe you are referring to the boiler aquastat? A (probably) gray box on the boiler, (probably) Honeywell brand, about 4" x 6" ?

If so, you MUST keep that aquastat relay, and all it's wiring.

The 'green and red' wires you refer to... what terminals are they connected to on the boiler ?

Some pictures would help... free account / Image hosting, free photo sharing & video sharing at Photobucket / upload pics there / place link here for us to view your album

 

What is the FULL boiler model number?

 

the boiler is a weil mclain model cg -4-spon series 12
the relay i am refering to is just inside the panel on the left side it is a small package boiler it comes with the boiler it has the transformer atatched to it with a plug in relay the 2 wires that i am tying together come right out of the whole relay assembly and are marked with a tag [G] on one and [R] on the other both wires are black the old ther used to go to them

 

Older W-M boilers used this:



instead of an aquastat control, and the G - R terminals are the connections for the thermostat, which you said was connected to these.

Wire the X1 and X2 to those two wires, leave all the other stuff on the boiler alone.

 

yes sir that is exactly what i have i did what u said and it works perfect thank you so much