When I had my gas boiler replaced in 2016, the 110 VAC single pole switch that supplies power to the furnace was malfunctioning. Probably because it was 36 years old and in a damp and dusty utility room and was rarely used in its service life. Nevertheless, the plumber got a replacement single pole switch and replaced it. Of course he messed up the wiring because the box had extra wires in it and he got confused. He assumed it was a simple box with the load and line wiring and that's it. But it turns out my house has 2 switches to turn off the furnace. One is upstairs in a foyer. The other is right next to the furnace (the switch I'm talking about that he replaced).
So he got it wired to properly switch power to the boiler, but the upstairs switch became useless and now I want to fix it.
I haven't opened both switch boxes yet, but since the original switch was a single pole switch and not a 3-way, I'm assuming the builder who built this house put these 2 switches in a sequence so that both need to be in the on position for the furnace to get power.
So assuming where the line power is, this is how I plan on wiring the 2 switches with the furnace. First, if the line power is coming into the upstairs switch, then I will wire the sequence like this:
However, if the line power is coming into the downstairs switch (which I think it is) I will wire the sequence like this:
My questions to this community are:
1) Is it normal to have two switches on a boiler circuit setup with two single-pole switches in sequence? Why don't they use 3-way wiring? Code? The house was new construction in 1980 in northern New Jersey if you're wondering.
2) If my wiring diagrams are sound, I have two low voltage transformers to wire into that downstairs switch box. The thermostat transformer and a doorbell transformer. What are my options on wiring them in this following diagram:
Ideally I would like the thermostat transformer to shut off with the boiler. But I'd like the doorbell transformer to stay on. If that's not possible, then it's ok for the doorbell transformer to shut off with the boiler and everything else.
Thanks for your help in advance!