Gas fired hot water boiler question

What make and model is the boiler. Many boilers have an aquastat for adjusting water temp.

It is a HydroTherm boiler but I don't know the model number. Our house is from 1963 and I assume it is from that year.

On the side of the boiler there is most likely a control box with line voltage and thermostat control wires within. Turn off the power, open the cover and there should be a small dial with temperature markings on it. There should also be a moveable pointer which designates the water temperature setting. If you are lucky, there will be information on the cover of this device... and yes it is an aquastat. Just curious, why do you want to lower the temperature? Most are set for optimum efficiency... maybe not 45 years ago.

Well my father in law keeps his at 180, ours was at 200 and said we should lower ours. I used a flathead screw driver and lowered it around 3 hours ago. But I did not turn off the power before I did that, it that a problem.

Nope. Just a precaution. Many a loose wire is hidden behind those covers. And 180 is fine... the boiler will most likely run longer, but the burners won't be on as much. If it heats sufficiently you will most likely save a bit on your fuel bill.

Thank you very much

Thank you very much

Thank you

You made the right move. Most hot water boilers(other than underfloor heat) are to be set at 180 to 190 (190 being max). 180 should work just fine, this is the standard.