A trip to ND turned up this boiler installation when a man asked if I wanted to take a look at his son's heating system. I will point out that I do them a little differently.

[Linked Image from electrical-photos.com]

Back-up Heat Source: [Linked Image from electrical-photos.com]

Fan/Coil Unit: [Linked Image from electrical-photos.com]

Main Circulating Pump (permanent wiring):[Linked Image from electrical-photos.com]

Primary Heat Source Pump (temporary wiring):[Linked Image from electrical-photos.com]

Domestic Hot Water (also permanently wired):[Linked Image from electrical-photos.com]