Nest Learning Thermostat

[Thomas7168]

Frustrated !!!!

simple 3 wire installation 

Common 

R

W

if I touch r and w together boiler fires 

if I connect nest to wall in the proper places on base plate 

nest shows heating but hot Water radiator boiler does not fire. 

how can this be ? Doesn’t the nest just complete the circuit between the R and the h ?

why wouldn’t the heat fire. 

no error messages on the nest. 

please help 

[Patrick_Caezza]

What type of heating do you have? Boiler with radiators, Boiler with zone-controlled valves?

Can you post a picture of the current thermostat's wiring?

If there is a Valve zone controller, can you post a picture of its wiring?

[Thomas7168]

Good Morning 

Thanks for your help. 

So I got the boiler to fire. T-stat wires were the issue. 

However. When I connect my C wire it shows red. I have never had a c wire connected before. I was able to use a spare wire to bring a c wire up to the Tstat 

It’s a zone valve hot water radiator system 

Burnahm 

It has a 24v transformer/relay Honeywell power center at the boiler. 

When I use a meter at the tstat and also at the boiler to test across the

Rh and C I get 24v however when I connect the C to the base the c shows red and I get an error message. 

When I disconnect the C the tstat works fine. 

I would like the C connected because of all the issues I read about operating the Nest without it. 

Any suggestions? 

[Thomas7168]

 

[zoeuvre]

Hi there, 

Thanks for posting here in Community @Patrick_Caezza, and I'm sorry for the late reply. 

Nest Learning Thermostats can typically work without the need for a C wire because they can draw power from your system's heating and cooling wires. However, can you help me with what the power error message that appeared on the Nest Thermostat display while the C wire is connected to its base? 

I'll look forward to your response.

I appreciate the help, @Patrick_Caezza. 

Best,

Zoe

[Jake]

Hey Thomas7168,

I wanted to check in and see if you managed to see Zoe's post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.

Best regards,
Jake

[Jake]

Hey there,

I wanted to check in, and let you know that I will be locking the thread in 24 hours.

Best regards,

Jake