Nest E to 2-wire boiler

[Lokihome]

Old Honeywell thermostat RH230B 2-wire r and w.  Blue and green present but not used.  Try to install Google tech said attach all wires to new E.  Got thru install to NO POWER.  Checked wiring all tabs down in neat(fully engaged).  Suggestions please 

[Eitanros]

Hello @Lokihome, 

Thank you for reaching out to the community. I'm truly sorry to hear the thermostat is not receiving power after installation. I'm happy to help you!

To provide the most accurate guidance, I'll need some additional information:

• Attach a picture of your current wiring configuration.
• Attach a picture of your old wiring configuration.
• When you see "No power", is there any error code?
• Are the breaker HVAC system on?

Please, keep me posted. 

Best regards,

Eitan