Stack relay issue

Preston1

I have an old oil fired steam boiler with a Honeywell Type RA117A stack relay unit... Getting power to the ignitor but no power to the burner motor... Guessing I have to replace the stack relay unit... As a temporary fix, can I attach the burner motor wire to the ignitor contact? Thanks for any advice...

CTOilHeat

In a RA117A stack relay the ignition terminal de-energizes after the flame has been proven. So, no, this may cause the burner to light but wouldn't keep it running.

Are you measuring the voltage at the burner or on the "3" terminal of the relay?

Here is a manual for the relay, for reference.

http://inspectapedia.com/heat/Honeywell_RA_116A-RA117A-RA817A_Manual.pdf

Steamhead

If you're not going to replace the boiler, I'd upgrade to a modern control if the burner has a mounting for a cad cell. The RA117 has an excessively long trial for ignition (70 seconds to shut off the burner if it doesn't light) as opposed to a modern control's 15 seconds.

What burner is on that boiler?

CTOilHeat

Agree with @Steamhead.

Honestly anytime a stack relay is removed from service, the world is a slightly better, safer place.

Paul S_3

i agree to with @Steamhead i think stack relay is very dangerous ....ive seen the take minutes to lock out..... and ive seen them blow flue pipe off the boiler

Preston1

Thanks for all the input / advice... I had a friend come over and he found the bad circuit board connection on the stack relay... Back up and running... Replacing the boiler this summer making the world a safer place.... I just need to get 2 more months out of it....

HVACNUT

Replacing this summer. That's what they all say.