Thermostat Spark

[Mo]

I have noticed a flash (like a spark) coming from our thermostat. I have noticed it only at night probably because it is easier to see in the dark. It has only happened a few times. I don't know if it has always done this and I haven't noticed or if there is a problem. Do themostats produce a spark occasionally when the heater kicks on? Is this an indication that I need to call a repair person? What could be the possible causes of this if it is a problem?

Thanks in advance for any information anyone can provide.

[sonc]

This is normal, no problems..

Hvac mechanic

[Mo]

Thanks for responding. Can you tell me what is causing the spark?

[Hube]

As Sonc said, "no problem"... the Thermostat ( 24 V ) is like a SWITCH, it has similar contact points. When a electrical charge is bridge across a contact gap, there can be a "spark". This is the electrical voltage doing its job. If you remove the cover plate on some wall switches (110 V ) and turn the toggle off and on a few times, you will sometimes see a slight spark. This is common. Hube

[Mo]

Thank you for the information. I've been a homeower for over 20 years and have never noticed it before so I thought it was unusual. And my son noticed it during the same time period I did which I also thought was an odd coincidence. I vacuumed out the thermostat thinking perhaps dust build up might cause it to short out. We had the thermonstat replaced about a year ago and I thought maybe whatever had caused it to go bad the first time was happening again.