thermostat troubleshooting

12-27-12, 11:28 PM

hi,
decided to replace old mercury thermostat with Honeywell TH2110D1009 Pro 2000 Single Stage 1-Heat/Cool Thermostat from amazon.com (sorry not allowed to paste links apparently).

Old thermostat had only 2 wires (R and W = so only heat, no fan).
Connecting new thermostat was a breeze the problem is the heat does not start. Had a couple of calls with Honeywell customer service and i am still not sure what's going on.

So if some one can explain what i am seeing :
1. Using a voltage meter, i am measuring ~ 25 VAC between R and W. According to Honeywell, the thermostat i bought only works with 750ma so that's why it does not work and i have to get a 24 VAC one. That some what makes sense.

2. If i by-pass the thermostat and manually connect the R and W wires directly, which is all the (mercury) thermostat is doing anyway at the end of the day, the heat still does not turn on. So i am very confused.

3. I checked the fuses box. The apartment has a gas furnace in the basement ( i think it's one for heating and hot water) and hot water is working fine.

any help is appreciated,
thanks in advance

Daox · 12-28-12, 03:04 PM

It doesn't really make sense, but does it work if the old thermostat is hooked up again?

12-28-12, 03:12 PM

you are right - it does not. but the sure thing is if i connect the lines manually, the heat furnace should have fired up and it definitely does. I have a technician come to see it in a couple of hrs. I think the hot water and heat may be separate.
I discarded the old thermostat (a bit careless) but there is no way it would have worked either given that direct connection does not work now.
thanks for you reply

Daox · 12-28-12, 04:53 PM

Quote:

Originally Posted by pipodnmy

but the sure thing is if i connect the lines manually, the heat furnace should have fired up and it definitely does.

Alright, I'm getting a little confused. In the first post you said manually connecting the wires didn't turn the heat on, but now it seems it does?

12-28-12, 05:34 PM

Quote:

Originally Posted by Daox

Alright, I'm getting a little confused. In the first post you said manually connecting the wires didn't turn the heat on, but now it seems it does?

sorry, i meant "it does not". the repair man was very shady, touch a few things on the furnace and it is working.

Daox · 12-28-12, 05:40 PM

Well, its good to hear its working. Did he explain what he did?

12-28-12, 05:44 PM

that's the shady part. he said he just fixed some part but his english was very bad and combined with his attitude did not understand much of what the problem was. i know he did not much in a few minutes but that's all.

12-27-12, 11:28 PM	#1
pipodnmy Guest Posts: n/a	thermostat troubleshooting hi, decided to replace old mercury thermostat with Honeywell TH2110D1009 Pro 2000 Single Stage 1-Heat/Cool Thermostat from amazon.com (sorry not allowed to paste links apparently). Old thermostat had only 2 wires (R and W = so only heat, no fan). Connecting new thermostat was a breeze the problem is the heat does not start. Had a couple of calls with Honeywell customer service and i am still not sure what's going on. So if some one can explain what i am seeing : 1. Using a voltage meter, i am measuring ~ 25 VAC between R and W. According to Honeywell, the thermostat i bought only works with 750ma so that's why it does not work and i have to get a 24 VAC one. That some what makes sense. 2. If i by-pass the thermostat and manually connect the R and W wires directly, which is all the (mercury) thermostat is doing anyway at the end of the day, the heat still does not turn on. So i am very confused. 3. I checked the fuses box. The apartment has a gas furnace in the basement ( i think it's one for heating and hot water) and hot water is working fine. any help is appreciated, thanks in advance Last edited by pipodnmy; 12-27-12 at 11:31 PM..

12-28-12, 03:04 PM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	It doesn't really make sense, but does it work if the old thermostat is hooked up again? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-28-12, 05:40 PM	#6
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Well, its good to hear its working. Did he explain what he did? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-28-12, 03:12 PM	#3
pipodnmy Guest Posts: n/a	you are right - it does not. but the sure thing is if i connect the lines manually, the heat furnace should have fired up and it definitely does. I have a technician come to see it in a couple of hrs. I think the hot water and heat may be separate. I discarded the old thermostat (a bit careless) but there is no way it would have worked either given that direct connection does not work now. thanks for you reply

12-28-12, 05:44 PM	#7
pipodnmy Guest Posts: n/a	that's the shady part. he said he just fixed some part but his english was very bad and combined with his attitude did not understand much of what the problem was. i know he did not much in a few minutes but that's all.