Burner Won't Start

lee_7

I don't like settings that high, not enough margin for steam being made. We set ours at 180/160. This is hot enough for dhw by immersed coil or indirect tank

Mike Bromley

Burner Won't Start

The subject is a little misleading, but I couldn't think of a better one.

I have an oil fired boiler that won't start when the temp drops below the low set point. It's not that it won't lite, it doesn't even try. If I press the reset button it fires right up. The boiler has a tankless coil for domestic hot water. With the hot water running the temp will drop to 160 and I can hear the Honeywell Aquastat trip. I watched the temp drop to 140 and still nothing. I did my usual single press of the reset button and it fired. If it helps, the aquastat is set to HI-190, LO-160, and DIFF-10.

Thanks,

Mike

steve_29

If you have to press the reset button on the PC it's not the aquastat.

Sounds to me it's locking out. You could have one problem or multiple problems.

Without actually looking at your system it's very hard to diagnois this problem, I'd suggest you call a professional.

As far as your setting they should be 200 hi / 180 lo you can leave the dif were it's at.

good luck

steve_29

It has been my experience that tankless coils perform best set at a 180 min . temp.

I also think Tankless coils are a very wasteful manner of producing DHW, due to the fact you must maintain high boiler temps all the time.

An indirect would certainly be a better choice