Taco sr502 and honeywell w8665e
I'm trying to hookup a honeywell w8665e wireless thermostat receiver module to a taco sr502 relay for a heat application. I'm really unclear on how it should be wired. I'm thinking that the zone 1 thermostat on the sr502 should wire to W zone 1 and C on the w8665e, and that I should wire R on the w8665e to the 24VAC teminal on the sr502. Taco doesn't really seem to have any docs that show use the 24VAC terminals of the sr502, they just say it can support 24VAC in or out. I'm not sure if the sr502 can power the w8665e or if I need an external 24VAC transformer. - Mac Nobody? I've contacted Taco and honeywell both - no answers yet... - Mac I am not real familar with that thermostat but looking at the wiring digrams it looks like you need a relay between the transm9itter and Taco control. You can use the SR50X 24v power supply for the isolation relays and the transmitter. I'm guessing that I need the relay because both the sr502 and the w8665e both put 24vac onto the thermostat connections. Is that right? made it work - just the sr503 and the w8665e, no other transformers or relays. I'll put the details in the next post... - Mac I hooked my w8665e to zone 1 of the TACO sr502, and assigned my t8665a to zone 1 of the w8665e. Leave all the w8665E dip switches off until everything is wired up. SR502 COM connects to w8665e C SR502 24VAC connects to w8665e R Next are the actual thermostat connections. I'm designating right from left because if I flipped the connections on mine, the circulator came on and stayed on. SR502 TT (left) connects to w8665e W (zone 1) SR502 TT (right) connects to w8665e RZ (any RZ works) Get your actual T8665A thermostat ready to go. Turn on the W8665E dip switch for zone 1. The red light for zone one flashes. Turn on the fan on the T8665A. The w8665E finds it and assigns it to zone 1. The green light on the w8665e flashes, then all the lights go out. When the W8665e is idle, waiting for the t8665a to tell it to do something, none of it's lights are lit, so there is no indication that it's powered up at all. - Mac [edit: I think I misunderstood what Mac was saying when I wrote this... see revised drawing and post below] Mac, I don't think that's right ... You should have no wires from the 8665 going to the TT on the 502 panel ... The TT terminals on the 502 should go ONLY to the boiler, where the thermostat would connect. The way you've got it connected you are running the risk of burning out the transformer in the 502 and/or the boiler aquastat. Which aquastat is on your boiler ? You've got the C to C correct. The R to R is also somewhat correct... I say 'somewhat' because: Technically, the ZONE inputs on the 502 contain an R and a W terminal, although they may not be labeled such. Do you have a voltmeter ? Set it to measure 24VAC. Put one lead on the C terminal. With nothing connected to the ZONE inputs, measure each ZONE terminal. Apply power to the 502. You will find 24VAC on one each of the ZONE terminals, and ZERO volts on the other. The one that you find ZERO volts on is your W terminal, and that's the one that should connect to the W on the 8665 . You can connect the R from the 8665 to EITHER the R terminal on the 24VAC power terminals on the 502 OR any one of the R terminals on the ZONEs ... I can't imagine how the way you have it connected is working at all ... other than perhaps bypassing the 502 and backfeeding the aquastat. In any case, it's wrong, and you should correct it. Where's Jay11 when ya need him ? He's the expert on those t'stats ... ohhh JAY! where are you ? I believe this is how it should and may be wired: Does this look right to the rest of you gurus ? NJ, I agree with what you have drawn up on there. Did you draw that out? YOu did a good job... How did you do it? Photoshop ... use the tool in Adobe to copy image to clipboard. Paste as new selection. Then, the eraser tool to take out what you don't need, and the draw line tool to add the connections... Oh, and the text tool to add annotations where needed. goes pretty quick once you get the motions down. Thanks for checking this out! I wanted to be sure... Ok, Cool.. I have to reload some software on my computer.. The hard drive crashed!! I agree with NJ Trooper. I too think there is a risk of burning out a transformer (probably the aquastat's) as it is wired. I just looked at Mac's last message again and I don't think I understood what he was trying to describe ... At first I thought that the terminals he was referring to as the SR502 TT terminals were the output to the boiler ... I'm pretty sure he was referring to the ZONE INPUTS now. I think he meant that he connected W on the 8665 to the left hand ZONE IN terminal which must be the 'W' terminal on the SR502 (I edited my schematic to reflect change). However, the wire from RZ to the 'right hand TT' (or ZONE IN) terminal is a redundant connection and not needed, but won't harm anything. In the 8665, the RZs are all internally jumpered to the R. In the 502, the 'right hand TT' terminals must all be 24VAC, or R, and this would explain why the circs ran when the wiring was reversed. I'm revising and re-uploading my drawing... so, Mac, if you come bac, I think my drawing shows the way that you have it wired, (with the exception of the extra wires from RZ to 'right hand TT' which I've left off my drawing), yes ? I dont know if the wiring is the same (or similar) for the HW W8665e compared to the Taco ZV406. But the terminals on the ZV 406 for the zone valves cannot be used for the TT terminals on the SR 502. They provide power to the zone valves. I have a ZV 406 wired to a SR 503. Wired this way allows the zone valves to close when there is a priority call. http://s168.photobucket.com/albums/u...trolwiring.jpg (Edit) Nevermind. For some reason I was thinking that the W8665e was a zone valve controller. Yes this is what I did - except I have the redundant right hand TT to RZ in there. I was unaware that it was not needed. Thanks a really nice schematic you made! Thanks for the help. - Mac Originally Posted by NJ Trooper I believe this is how it should and may be wired:
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