I just installed my TrueSTEAM 12 gal humidifier with the Vision Pro IAQ thermostat with EIM on my single stage HVAC system. The thermostat and HVAC system work perfectly together as well as the outside temperature gauge is working correctly. My problem is with the TrueSTEAM...The service light flashes 7 times after I hit the "go" button to initiate steam production.

The installation manual I have and followed is 69-2285EF which can be found here under the literature tab: Honeywell Air Cleaners, Commercial & Residential Filtration Systems & Purifiers. -TrueSTEAM Humidification System

According to the manual, the 7 flashes denotes that the HVAC power is not present which is not the case since everything is working properly except for the TrueSTEAM. The TrueSTEAM is plugged into a dedicated 20A circuit, so that shouldn't be a problem.

Because I want the fan delay option turned on, I wired everything according to the diagram on page 21 of the installation manual ("Option 3: VisinPRO IAQ Wiring with Fan Delay" at the top of the page). DIP 4 is down and the installer setup #0374 is set to 3. I think the problem is with the R wires but I'm not sure. Inside the TrueSTEAM the R terminal is factory jumped with the RT terminal and inside the EIM the R terminal is factory jumped with both the RC & RH terminals. Should these jumpers be removed to clear this service error?

I would appreciate some direction on this matter before I start a trial and error method. Thanks!

 

The jumper stays in place on both unit.

Do you have a meter to check for power at R on the TrueSTEAM?

 

thanks for replying.

I do have a meter to check. Do I check it between the R & C terminals and am I looking for around 24V?

 

Yes, you should be seeing around 24 volts at R and C at the TrueSTEAM.

If you don't see power, then make sure the wires is tied up on EIM R's and C.

 

The R wires aren't twisted together at the EIM but are snug in the terminal if that is what you meant. Testing across the R's and C of the EIM, I get 29V. When I tested the TrueSTEAM across the R & C terminals all I got was about 3V (there is no C wire hooked up on the TrueSTEAM per wiring diagram in original post).

 

Humm.. I wonder if someone forgot to add the C hook up in the drawing..

Hook up the C..... and let me know what happens.

 

I'll try it tonight and let you know what happens. Thanks

 

I'm finally a happy camper...your suggestion of hooking up the C wires between the EIM and TrueSTEAM was the answer!

I've looked through at least 3 different (current and older) versions of this installation manual and none of them had the C's being hooked up together between the EIM and TrueSTEAM.

I'm crossing my fingers that everything keeps working!

Thanks a bunch Jay!

 

Glad to hear it's working.

Not sure why it was left out, you need Com to complete the power path...

 

I had the same issue... It's 2 years later and the docs still don't show that connection. Thanks for the info!