No Heat, Jumper Cable Came Loose

RyanNYC

Good Afternoon,

I have a Slant Fin Galaxy GXH Steam Boiler. When installed there was a jumper cable put in I believe to bypass the vent damper. The jumper cable came loose and I was wondering if anyone could help me figure out how to jumper this to get the heat back.

The 4 wires in the harness are yellow, purple, red and blue.

Yellow is going to 'R' terminal on the transformer
Purple is going to 'C' terminal on the transformer
Red is going to the roll out switch
Blue is going to the thermostat.

There was jumper in place between two of these wires and it falling out I have no idea which way the jumper needs to be arranged.

I appreciate the help in advance, thank you

pecmsg

Why was a Safety bypassed?

RyanNYC

The damper was never installed 

EdTheHeaterMan

If you have the 4 pin plug you jumper 2 & 3 Here is the wiring diagram of the plug however I do not know if this is looking at the male or female end. So if you jumper 1 & 4 you will have a dead short and then you will let all the smoke out of the transformer. So I would use a fused jumper using an automotive 3 amp fuse and some spade connectors.




In your case it appears that your Red and Blue are the ones that would be connected to 2 and 3 ...but electric is colorblind and things may be different. So, use a fused jumper so you don't need to buy a new transformer.

pecmsg said:

Why was a Safety bypassed?

I don't look at this jumper as bypassing a safety switch if there is no damper, there is no "closed damper" that needs a safety switch.

Here is a discussion on vent dampers from January of this year several diagrams all indicate the 2 and 3 posts on the 4 pin connector are the safety switch for when the damper is closed and the flame should no operate. https://forum.heatinghelp.com/discussion/182805/ruh-roh-boiler-wont-fire-w-new-auto-vent-damper-on-auto https://forum.heatinghelp.com/discussion/182805/ruh-roh-boiler-wont-fire-w-new-auto-vent-damper-on-auto

mattmia2

It would be red and blue if they go to other safeties(the rollout switch and the t-stat). The switch on the damper would be in series with the other safeties.

RyanNYC

Thank you guys so much. I have re-attached the jumper and Heat Is ON!

MikeAmann

Nice idea with the fuse in the jumper ED.
.....let all the smoke out of the transformer. LOL

EdTheHeaterMan

MikeAmann said:

Nice idea with the fuse in the jumper ED.
.....let all the smoke out of the transformer. LOL

Mike, you may want to get one of these.


I was tired of burning up fuses while trying to find short circuits on control wiring. This works great with alligator clip ends on the wire. I had a 3 amp and a 5 amp floating around my "electric" tool box. The box full of meters and jumper wires and and my ECM motor tester. in the lifetime of fuses I burn out diagnosing control wiring, I could have purchased 20 of those circuit breakers. (maybe more like 100 if you count the transformers I smoked before I started using fuses)

mattmia2

You could use a light bulb as a thermistor to limit current as well.