I just purchased a totaltouch P286-1300 which I know is a little bit of over kill for my system, but I like the way it looks. Anyway, I just a simple two wire baseboard gas heating system. When I connect the wires the screen lights up and comes on just fine. When I use the system the thermostat continually clicks on and so does the furnace. I checked the website of the thermostat and it said I need to use a common wire for a gas furnace. I traced the wiring to a honeywell aquastat relay type L8I48E. The wires are connected to terminals TV and T. There are W and Z left untouched with just a jumper in between them connecting them together. I don't see where a common wire would be connected unless its just supposed to be grounded? I Don't know! Any help would be greatly appreciated! Thanks!

Scott

I found the Aquastat manual here: http://customer.honeywell.com/techlit/pdf/95-0000s/95-6940.pdf

Right now, I'm too tired.

Hahaha! Damn, I looked around for that too! Thanks! Maybe that can lead my way

I still don't get it... what is the common wire supposed to be connected too?

There are 2 wires come off the transformer furnishing the 24 volts. One goes directly to the thermostat commonly called the hot. Often it is blue. (Oops! That should have been red) The other connects to the one side of all the coils in the relays and is called the common. Often it is blue.

For more info, see the sticky at the top of the forum here.

Z = Common (Black)
Rh = TV (Red)
W = T (White)

All right, thanks guys, I will give that a try

Z = Common (Black)
Rh = TV (Red)
W = T (White)

right now Z is jumpered with W, should I remove the jumper?

No.

Thanks, that seemed to fix my problem!

I probably should have explained how I got the answer and you probably should have rated me. You still can.

The schematic was tough to find. That info is always useful. Your stat bridges T and TV. Basically there needs to be a switch there. Thermostats don't have isolated contacts, they switch one side of the 24 V transformer. For heating, the side that would be connected to the transformer would be Rh which can be TV or B3 on the aqqustat. I chose TV becase that is indeed a T-stat wire.

Now we need the other side of the switch which as to be T and this corresponds to W on a heating stat. So, now we have one side of the xformer going o Rh (TV ) and coming out on W (T).

Now common is easy. It's the other end of the transformer. The closest terminal to the transformer is (Z). TP and W are ignored because there are jumpers to Z. The jumpers may or may not be used in your situation, therefore (Z) is the safest choice.

I was tired and sleepy so I couldn't think clearly, but I at least was able to post the diagram. You tried and that's why I'm posting the reasoning behind the choice.

KISS