[Candide08]

This may take a bit to explain - but:
- I have two new thermostats, a Honeywell Vision Pro 8000 and a White Rodgers 90 Series (1F97-1271). These are both touch screen and appear very similar.

My system is heat only, and until recently I thought it was a standard system. I have a 24v system that fires an oil burner.

Here is the issue:
I replaced the old stat with the Honeywell and it is working. I had to put the RED wire on the Rh (heat) contact and the YELLOW wire on the W (relay) - nothing is on the COMMON contact. If I wire it with red on Rh and yellow on C it does not fire the boiler.

If I wire the White-Rodgers (WR) this way it simply does not work. The heat never comes on.

I tried wiring the WR with the red on the Rh and the Yellow on the Common - and the stat works, it clicks on, it says the heat is on, but the boiler never fires. I tried jumping from the common contact to the W relay contact - but the stat clicks on and off continuously.

Why is the White-Rodgers stat not working?

Thanks in advance for all replies.

[hvac1000]

((I replaced the old stat with the Honeywell and it is working))

So what is your reason for messing with the white rodgers thermostat?


http://www.white-rodgers.com/wrdhom/.../0037-6664.pdf

If you attach the Red and yellow together your boiler should come on. If it does and you reattach the wiring to the RH and C terminal the unit should work.

NOTE go through the INSTALLER/CONFIGURATION MENU and change settings to suit your system. Especially item number 4 (Pick Heat Only setting)

[Candide08]

I am splitting the current heating zone to add a new zone.
I wanted to move the Honeywell to the new zone and have the WR for the existing zone.
Either way I need both stats.

If the wires are crossed the boiler does come on.
However if they are attached to the Rh and C on the WR the stat clicks says "stage1" - but the boiler does not come on. I have picked heat only from the installer config menu.

Sort of a side question - if I connect the Honeywell as Rh and C the boiler does not come on, the yellow has to be connected to the W contact for it to work. Why does it not work with the C contact?

Thanks for the reply.

[NorthernHeat]

((I replaced the old stat with the Honeywell and it is working))

So what is your reason for messing with the white rodgers thermostat??


http://www.white-rodgers.com/wrdhom/.../0037-6664.pdf

If you attach the Red and yellow together your boiler should come on. If it does and you reattach the wiring to the RH and C terminal the unit should work.

NOTE go thru the INSTALLER/CONFIGURATION MENU and change settings to suit your system. Especially item number 4 (Pick Heat Only setting)

If yellow wire is the heat control voltage wire do not connect it to common. If that version of visionpro requires voltage from the transformer instead of batteries you do not have enough wires from the furnace.

R goes to Rh you may or may not need a wire to common (ie. Battery powered) and if yellow goes to the W terminal on the furnace that needs to go to W on thermostat.

[Candide08]

I measured the voltage across the wires and it is 28.8 volts AC.
This activates a hot water - oil burner system w/ circulator pump.

The VisionPro is working, the boiler fires, and maintains heat.
It has the Red connected to R (which is factory jumpered to the RC terminal).

The WR stat also has the Rh jumpered to the RC terminal - but when I connect the yellow wire to the W terminal it appears that the thermostat itself does not work - the backlight does not come on, it does not click and activate "stage 1" (heating).

If I move the yellow to the C terminal the stat appears to work, the backlight comes on and it activates "stage 1" like it it trying to turn on the burner - but the burner does not fire.

Either way the burner does not fire and there is no heat with the WR thermostat.
I am trying to determin if the stat is defective or just not compatible with my system.

Thanks...

[biggsie]

I think the one thing that comes to mind is programming not set to call for heat

Can you use a meter to test the thermostat -- RC to W and RC to G

Should have continuity on both circuits -- Let me know how you do

[Candide08]

RC to W does not have continuity, Rc to G and Rc to C does have continuity.

But when I am doing this the display does not show "stage 1" - as it would if it were calling for heat. The only way this stat shows "stage 1" is when yellow is on the C terminal.

[Candide08]

Ok - this was getting strange, so I removed the batteries from the WR stat and reset the unit.

I entered in the program and heat only settings, connected the red to Rc and the yellow to W - and it is working.

Thanks to all for your time and replies.