Thermostat Clicks But Heater Does Not Start

Welcome back to Kung Fu Maintenance!

Wanted to tell you, show you, about one I had the other day. What happened was right at the end of the day I saw that there was a work order for a no heat call. Went and checked it out.

The hydronic valves were turned off and turned those on. Came over to the thermostat and turned it on but nothing turned on.

I could see. the flame signal here. Much like this one. Now usually when you do it you will hear the little click when it turns on. On that particular one I did hear the click and that kind of signified to me that the thermostat was working.

I turned the fan to on. The fan kicked on. I turned the A/C on and the AC kicked on. Turned it to cool and auto. Lowered the temperature down and everything kicked on there right away.

So I knew at that point that it wasn’t the service door switch. Didn’t know what it was but what I did was pull the cover off.

Now before I do that I want to show you the little click. I will raise my temperature up so the heater will turn on a little bit.

You hear that click?

That’s signifying that my unit is getting ready to fire up as the heater has now been signaled to turn on.

But underneath. I will show you here. What you have got is your red cold jumper and the red hot jumper wire. That fatter red wire that is back there. I got kind of lucky and noticed right away that the insulation part, even much like it is here, the insulation portion was up inside the screw port.

So All I had to do was loosen the screw a little bit. Move the wire down a tiny bit so that the wire was actually making contact with the screw port so we would have continuity.

And that’s all it was. The screw instead of clamping the wire down was clamping the insulation down. Insulation was making contact so that the heater wasn’t turning on even though it was sending the call for heat from the thermostat. It wasn’t being transmitted through the hot wire so.

Nice easy fix. Thought I would show it to you guys. Hope it saves you some trouble.You know. It’s rare but these are the things that happen and a little bit on the troubleshooting that happens.

Obviously if a wire is not making contact there things are not going to turn on. And one other thing I had checked on this which should be checked when a thermostat is not working. One thing to check on theses is the jumper pin or the switch setting.

This one has a little switch down here where right is for gas heating and left is for electric heating. That particular one was set for electric heating which is common to all of my other units for hydronic heating. So it wasn’t that.

So again it was that insulation that was blocking. So that the wire wasn’t making contact on the RH wire.

Anyway. Thanks for watching!