Best Of

We all first tried just replacing the motor , learn from our mistakes .. :)

Either way should work, although having relays in series is just more stuff to fail. However it keeps the boiler wiring consistent with the OEM drawings.

With all the detective work you guys have done on my behalf, I kinda feel like I've let you down ordering a replacement part 😂

You need to know your meter…. on my digital meter 000.0 ohms means no resistance. Closed circuit. For an open circuit my meter would read OL which was translated from the infinity symbol (∞) on the old analogue meters in the original instruction manuals. But that was back in the day when old farts were converting from analogue Simpson multi meters to Digital stuff and they thought we needed to be told that ∞ = OL.

I ordered a replacement from Supply House. Will arrive tomorrow

relay is bad. once one contact welds it can hold the other contact closed or it could be a broken spring or dirt making it stick.

@109A_5 Great Video! I believe the opposite happened to @FrankMaraschino's relay. The contacts are not open like in the video, but they are closed or welded together so they do not open when the coil is not energized.

I just thought of a fix for this that will not need any parts. If you use the 5 and 6NO on the SR501 to do what that general purpose relay is supposed to do.

Diagram to follow:

Since all the CR1 contacts on the problem relay do is connect Y to R on the Transformer terminal board, then we can just use 5 and 6NO to connect R to Y on the transformer terminal board. The SR501 is already doing what the CR2 contacts are supposed to be doing, just use the SR501 to do both jobs.

It is easy to do… Just take the wire that is connected to G on the transformer terminal board and place that wire on Y on the transformer terminal board. Very simple fix…. Just remember to leave the CR relay out of the socket.

For proof of concept of @EdTheHeaterMan's no parts required fix, remove the 'CR' relay and jumpering R to Y should have control of the boiler. R to Y closed boiler fires, jumper removed R to Y open the boiler shuts down. Seems promising since the boiler did not fire with the 'CR' relay removed.