https://www.googlenestcommunity.com/t5/Nest-Thermostats/No-Power-after-installing-Power-Connector/m-p/649883#M126544 <P>I just purchased a Nest Thermostat. I have a heating only controller with 2 wires. This works, but there are issues due to no C wire. I purchased the Power Connector and installed. However, after this was installed, there was no power to my thermostat at all. I checked all the wires 5 times, and they are correct. The C wire was hooked up to my COM port (I have a Taco SR503 board), but there is no power with or without this hooked up.</P> Thu, 17 Oct 2024 00:38:12 GMT dubby25 2024-10-17T00:38:12Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/No-Power-after-installing-Power-Connector/m-p/649883#M126544 <P>I just purchased a Nest Thermostat. I have a heating only controller with 2 wires. This works, but there are issues due to no C wire. I purchased the Power Connector and installed. However, after this was installed, there was no power to my thermostat at all. I checked all the wires 5 times, and they are correct. The C wire was hooked up to my COM port (I have a Taco SR503 board), but there is no power with or without this hooked up.</P> Thu, 17 Oct 2024 00:38:12 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/No-Power-after-installing-Power-Connector/m-p/649883#M126544 dubby25 2024-10-17T00:38:12Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/No-Power-after-installing-Power-Connector/m-p/649902#M126551 <P><a href="https://www.googlenestcommunity.com/t5/user/viewprofilepage/user-id/606218">@dubby25</a>&nbsp;</P> <P>The Taco valve controller is notorious for being a pain to use.</P> <P>Your best option is to use an external 24Vac transformer and wire it like this.</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="2022-03-01_173137.jpg" style="width: 330px;"><img src="https://www.googlenestcommunity.com/t5/image/serverpage/image-id/53596iF8C540F9611E7167/image-size/medium?v=v2&amp;px=400" role="button" title="2022-03-01_173137.jpg" alt="2022-03-01_173137.jpg" /></span><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="2022-04-06_182952.jpg" style="width: 326px;"><img src="https://www.googlenestcommunity.com/t5/image/serverpage/image-id/53595i6F5BD15712DCF7E2/image-size/medium?v=v2&amp;px=400" role="button" title="2022-04-06_182952.jpg" alt="2022-04-06_182952.jpg" /></span></P> Thu, 17 Oct 2024 03:08:23 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/No-Power-after-installing-Power-Connector/m-p/649902#M126551 Patrick_Caezza 2024-10-17T03:08:23Z