I'm replacing a basic round Honeywell HEATING ONLY t'stat (without any switches) for a hot water system with a programmable digital to save energy. The White Rogers zone valves have three wires, white red and green. Is the wiring straight forward at the new thermostat end? Thanks Nick
Nick, there are probably just two wires at the thermostat end... likely a white and a red ... as far as the t'stat goes, shouldn't make any difference what zone valves are used ...
Have you removed the old t'stat yet for to take a look ?
I'm pretty sure that's what you'll find.
It's quite possible that your White-Rodgers zone valves require three-wire (SPDT) thermostats for operation. W-R made several such zone valves and they require the thermostat to close red to white to open the valve on a coll for heat and then to open the red/white connection and close red to the other color (in this case green) to close the valve.
If this is the valve you have then it will require a SPDT relay (with 24 volt AC coil) to be connected between the two-wire thermostat and the three wire valve.
Post back if you need more information.
Furd,
It is a 3wire White Rodgers zone valve #1311-102. There are three wires, red, white and green. The old t'stat had red-to-red, white-to-white and the green wire attached to the Y terminal on a Honeywell series 20 t'stat. It had no control switches.
Would you recommend a specific replacement or can I just pick one up at Home Depot that is a (SPDT) . The goal here is to replace the old analog with a digital so that I can program it for energy savings. Thanks. Nick (phone # removed for personal security reasons, PM Nick if you want his number)
Sorry, but I cannot recommend any particular thermostat. I doubt that you will find a suitable SPDT thermostat at any retail store so the easiest way to make a SPST thermostat work with these zone valves is to use an intervening relay.
You would need a relay with a 24 volt ac coil and SPDT (or DPDT) contacts to actuate the valve. One relay that would work is a Potter Brumfield model KRPA 11AG-24. You would also need the socket for this relay which is part number BDS08SS. These are common and readily available from several mail-order sources or from industrial electrical/electronic distributors in major cities. I give these examples of PB only because I am quite familiar with the products. There are several competing products and any one of them would work just fine as long as you have the 24 volt AC coil and a minimum of SPDT switching.
The thermostat ends up switching the relay coil and the relay contacts will operate the zone valve. NJ Trooper can probably make a wiring diagram better than I.
Here is the instruction sheet for the W-R zone valve:
http://www.partsguy.com/pdf/1311troublshoot.pdf
While you can wire up a relay as furd suggested, I looked at the Honeywell VisionPro ($$$) and FocusPro ($) thermostats and found that they are useable with three wire power open/close zone valves.
It's probably worth the extra bucks to pick up a t'stat that can do what you want without the extra work (and cost) of adding a relay... you'll probably break even in the long run.
On both the VisionPro series 8000 and the FocusPro series 6000 t'stats, you would set the SYSTEM TYPE (FUNCTION 1) to #2 and wire as shown. They don't show the W-R valves though, only their own series 20 valves (which are also power open/close), so you would have to be careful which wires connected to which...
Tags: white, rodgers, zone, valve, wiring, zone valves, volt coil, zone valve, open close, power open
