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NO comm on my heating sytem

Mrjones
Community Member

I have an oil furnace heat only with 4 zones - 1 for hot water and three for heat.  I have 3 theromstats that i replaced with Google Nest. They each have Red and White wires only.  Low Power. SO i bought 3 google C wire power connectors.  My furnace has a ARM842 that all my thermostat wires go into.  I bought a AC 24 volt transformer C wire adapter (AC 24 Volt 0.5Amps) and connected it to one of the google power adapters and it worked.  I then connected it to all 3 power connectors and it doesnt work. I suspect maybe it is not enough power ?  i connected it exacly like the photo in your post and in the google booklet.  only difference is i connected all 3 C wires from the goolge adapter together with one of the power cables from the transformer with a wire nut and then did the same with all of the reds - 3 red zone wires, each with its own wago with a wire to the google adapter and a pigtail to the transformer power wire.  so 3 reds together with the wire on a wire nut.   Is my transformer under powered ?  if i get a different one will all be ok?  any other way to do this ?  again my furnace has NO comm or C connection.  

Argo ARM842

 

@Patrick_Caezza

4 REPLIES 4

@Mrjones 

Which Nest thermostat do you have?

Is this your valve controller?

00379566.jpg

For multiple Nest thermostats it's best to use a 24 Vac 40VA transformer. A 0.5A might work, but not reliabely.


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Mrjones
Community Member

@Patrick_Caezza   hi thank you for the response.  I have a nest learning and 2 Nest Thermostats (white with mirror face).  I ordered a 24Vac transformer with 40VA so when that comes this weekend I will swap it out.  Hopefully that works.   Your photo is not the exact same as mine.  I do not have the two connections on the top right corner and the two left boxes are inline on mine 6 across not staggered like in your photo. The labelling however appears to be the same.  

I dont know how to post a photo. My valve controller is the ARM842, voltage 120V 60HZ, 20VA, relay switching action DPST,Thermostat current 0.83, single phase motor rating each circuit/control 120V AC = 1/3HP, 240V AC=1/2 HP  

 

 

@Mrjones 

You can post a picture like this.

Camera icon.jpg

Sorry about posting the wrong image. I did a search for it, and that's what came up. This looks to be the correct one, yes?

ARM842.jpg


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brokkolo
Community Member

@Patrick_Caezza 

Jumping in the discussion as I have the same situation with 5 nest and 5 power connectors, and the same board (actually 2 of them)
I wanted to know if this wiring configuration is correct (removing the jumpers in the power connectors)

https://imgur.com/xi1Om6A 

(sorry but i'm not allowed to upload images)

thank you