What's the best way to wire up 2 boilers, circ pumps, service switches, etc.

[velvetfoot]

Two boilers, pellet and oil; installing pellet now. Currently, circulating pumps and thermostats fed by oil boiler power. Will be adding two boiler pumps. How should I wire it up? There's a switch now near the oil boiler that turns everything off. There's an emergency switch at the top of the stairs that turns everything off. The pellet boiler will be on its own circuit.

The oil boiler breaker will have to be on whenever the zone circs are running, so that breaker will have to be on, even if I want to take that boiler out of service, if the pellet boiler is still running. I guess I could just unplug the burner or wire up the local switch for that instead of taking everything off line. Each of the circs currently have a switch as well.

I guess I'll run another circuit up to the top of the stairs and add another switch for the pellet boiler. The zone circ pumps will still have power when only the pellet switch is thrown. Maybe a double pole double throw switch for both?

I'm still plumbing but my mind wanders.

What do you think?

 

[Clarkbug]

I use an STSS controller that uses an aquastat to trigger if I want the burner on my oil boiler to fire or not. It interrupts the signal from my zone controller to the burner terminals, and holds them open. Could be fairly simple to wire up with some relays if you feel like tinkering. I might have the wiring schematic kicking around somewhere if you want it.

 

[velvetfoot]

Thanks. I haven't gotten near that far, though the last time I read about it was months ago and I forgot it all.
I was just thinking about the power supply, not the controls.

 

[Clarkbug]

Ahhh, Ok.

I think you are Ok with your current setup for the oil boiler, since anyone who services it will want everything near it turned off. You can add another switch to separate the pumps from the burner if you like. You can also run the shutoff to the top of the stairs, but I dont think you need to worry about having the pellet switch kill the zone circs also.

 

[velvetfoot]

OK, thanks. I might add a switch for each new pump.

 

[maple1]

When I had my oil/wood combo, I added a simple switch to just my burner. Just surface mounted it to the side of the boiler. That way I could prevent my burner from kicking in when the wood side got temporarily down (or the box loaded up with coals - a frequent occurance) but everything else in the system was still up & running. I usually had it switched off all winter - unless we were going away. Also had the typical red switch at the top of the stairs that would kill everything - problem with that is it killed everything. Circ pumps and their controls are a good thing to keep active most of the time.

 

[velvetfoot]

Well, that cleared things up for me.