Wiring up a RIB relay

STEVEusaPA

Seem to be having a brain fart on this...
Want to use a relay (RIBU1C) to prioritize an oil-fired water heater over an oil fired furnace. Both have separate power supplies.
My thinking (see attached) is I wire the 2 red circled leads in series from the power supplied from the aquastat on the water heater. The 2 blue leads wired in series thru the primary control of the furnace.
Is this the right relay? If so, is this the right way to wire this?
Any help or guidance is always appreciated.
Thanks
Steve

billtwocase

Quick question Steve. Why are you prioritizing the water heater over the furnace? Is there a fuel or draft issue?

Ironman

The two reds are the relay coil and the two blues are the normally closed contacts. When the coil is energized, the normally closed contacts will open.
I'm not exactly sure what you mean by "wired in series thru the primary control of the furnace". I would hook the reds in parallel with the burner motor on the water heater and the blues in series with the "line" (black) feeding the primary on the furnace.

Robert O'Brien

The Long Island method is to break the TT on heat primary (assuming it has one) with the Blue/Yellow

billtwocase

I would also use "T-T". If you wire it in series with the motor, wouldn't there be a potential for it lock out on safety when switching over to the furnace? I might just be over thinking it.

Ironman

Robert O'Brien said:

The Long Island method is to break the TT on heat primary (assuming it has one) with the Blue/Yellow

billtwocase said:

I would also use "T-T". If you wire it in series with the motor, wouldn't there be a potential for it lock out on safety when switching over to the furnace? I might just be over thinking it.

That would be my first choice if it has "TT".

Bill,
If the motor is de-energized, power to the RIB coil is broken and the normally closed contacts make, energizing the furnace primary. I can't follow how that would cause a lockout, but maybe you see something that I don't?

STEVEusaPA

Thanks for all the responses. With our first cold snap, I was a little busy to respond/follow up.
@billtwocase‌...this is a new customer that had not had their 2 appliances serviced in 7 years. Based on how the flue pipes were installed (incorrectly), with two rotted flue pipes jammed into the chimney base, and reading a report on the tag about 'poor draft', I was concerned.
I was able to redo the flue pipes correctly, use a wye in place of a tee, change a 90 to a 45, and everything worked out.
Thanks also Bob & Robert, I'll save this for future use.
Steve

billtwocase

sounds like you saved some lives Steve. Always good work

billtwocase

Wouldn't it have been best to break at the primary for the HWH, and not the motor only? If the primary sends power to the motor, and no flame is established, it should lock out. I may still may be not following that particular wiring Ironman? If you have done this, and they both worked without lockouts, then I just learned something from you. Thanks

Ironman

Bill,
You're right. Hadn't thought about lockout. I was just thinking circuitry. Good eye.