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Techmar 400 into Lochinvar WHN199 wiring help!

jmoar Member Posts: 20
edited October 2022 in Radiant Heating

Issue #1: I am installing a Tekmar 400 controller into my WHN199 boiler. The install paperwork shows the controller connecting onto terminals 33 and 34 of the boiler and another set of wires going from 19 and 20 (Heat/Loop Demand 1) to the Stage 1 inputs on the 400 Controller.

I currently have two wires under the 19/20 terminals of the boiler and when i called Tekmar for help they could not answer it. I talked to two different people at Tekmar and one person told me that i need to use terminals 37/38 on the boiler and not 33/34 like my paperwork shows.

Needless to say, I really need some help or clarification on this. Not sure if i run a jumper across the one set or disconnect the current wires under the 19/20 completely and just do it like the diagram.

Issue #2: My system is installed with a DWH pump, a boiler pump and system pump. When i move the pump controls to the 400 there is not a control for the system pump. I have read that it should turn on the same time the boiler pump activates, but i cannot find that in the Tekmar literature anywhere. Can anyone tell me what to do? i'm assuming that I move both pump control hot wires to the same single wire on the 400, but i need to be pretty clear before i do all the final work and fire it up!

Thank you for any clarification for sure!