Barcalounger Job

Alan (California Radiant) Forbes

I'm calling this job the Barcalounger job because it's surely going to push me into retirement. It started out with areas of the house that weren't heating (ceiling radiant) and I'm still mired in that problem; the thread is here.

Another part of the job had to do with thermostats that were no longer communicating with the heating system. They were either cut during a remodel or somehow got severed or separated. We replaced them with Honeywell wireless thermostats and we installed three of them. Each thermostat has its own Equipment Interface Module (EIM). When the module receives a call for heat from the thermostat, it closes an end switch which is wired to T-T terminals at a Taco zone valve control. The 3 Honeywell wireless zone have this designation on the zone valve control.

Zone 1 - Living Room
Zone 3 - Master Bedroom
Zone 6 - Boy's Bedroom

Here's what came up: When zone 1 calls for heat, zones 3 and 6 light up as well. Zones 3 and 6 thermostats are not calling for heat. When I remove one of the T-T wires from zones 3 or 6, the call is still there. Furthermore, the end switches on the EIM are open for zones 3 and 6. In addition, when I remove the end switch wires from T-T from zone 1 EIM and jumper T-T, only the zone 1 lights up.

The first photo shows the EIMs. The red light on the left one shows a call for heat. The second photo shows a wire removed from zone 3 T-T and still yellow and red lights are on for that zone. The third picture shows EIM wiring.









When I left for the day, I turned thermostat 1 off. But when I went down to the boiler room, zones 3 and 6 still showed lights when the corresponding thermostats were off. By that time, I was pretty much finished for the day energy wise and went home only to get a text at 10pm that it was 80 degrees in the bedrooms.

Maybe @Joe Mattiello or @SteveSan can chime in on this one.

Sylvain

I guess each pair Thermostat/EIM has a different address.
Is it possible that the house next door uses the same thermostats with the same adresses?

mattmia2

Sounds like whoever removed the thermostats wired some zone valves together somewhere.

SteveSan

@Alan (California Radiant) Forbes Thanks for reaching out.

Are these t-stat just two wire stats ( I only see wires going the TT ). Do they need a common? If so, R goes to the right T and white going to the left T. Com would go to the number 1 zone valve terminal for that zone. If no common is needed, might just need a resistor across the W-C terminals. Ours is a 1000ohm 1/2watt.

If you have any further questions, please give Taco Technical Services a call during normal business hours Mon-Fri 8am-5pm EST 401-942-8000

Mustangman

You are dealing with more than 1 24v transformer. It behaves like another 24 v source may be crossed up somewhere. In the directions they want multiple EIMs mounthed at least 2 feet from each other. That is first step to take.

ratio

Alan (California Radiant) Forbes said:

Check the wiring on the EIM. It looks like you've got the zone panel connected to W & Rh, it shoudl be W to C.

Alan (California Radiant) Forbes

Rh and W gives me what I need, i.e. an end switch closure. Also, this is what Honeywell recommended.

But what I'm realizing is that it's not a dry contact. It took me awhile to figure out what I had done wrong:

I had wired Rh and W to the T-T terminals on the Taco zone valve control. I've always wired the T-T terminals to an isolated end switch, be it a thermostat or a dry contact. Polarity doesn't matter. But here, I had wired the W terminal on the Taco ZVC to the R terminal on the Honeywell EIM so that the W terminal was picking up a closure signal even when there was no call for heat.

@Mustangman hit the nail on the head, but I had to figure it out on my own. Thank you!

ratio

It's not dry with the R <->Rc <-> Rh jumpers installed. Pull one or both of them to make the Ys & Ws dry.