Wi-Fi thermostat with tekmar (260)? Has anyone done it?

JohnNY

Hello all,
I need to control a system pump and boiler pump with a cast iron boiler. That's a 260 to me.
Client wants a wi-fi thermostat (Red Link?) to work with his iPhone.

I've never coupled these two pieces before.
I assume I'll need a relay between the stat and the heat demand on the tekmar. Seems convoluted to you too?
Any help is appreciated.

JStar

Honeywell R8845U. We use this relay to interface all of our wifi tstats. It has a dedicated Common terminal, a control fuse, and three sets of dry contacts.

JohnNY

Thank you, Joe.
I was inclined to follow a schematic like this one without the relay, but I do like having options.

SWEI

JohnNY said:

I assume I'll need a relay between the stat and the heat demand on the Tekmar.

No need for a relay there.

JStar

I thought that the Boiler Demand sent power out and should not have voltage applied to it....?

SWEI

As long as the stat can close a relay, shouldn't need isolation. If for some reason the stat has a TRIAC instead of a relay, it gets a little more complex.

JohnNY

Boiler demand requires power in. 20-280v.
Can be make or break via a thermostat or other switch, but I often like to set it up with a constant demand and let it work off WWSD.
Every job is different....

SWEI

Gotcha. 24 VAC from pretty much anyplace you can find it will work since it's essentially zero load.