Burner Question?

With a high limit, it's all or nothing. The high limit switch is only there in case of a malfunction so the water doesn't get too hot. Once tripped, a high limit must run to stone cold before it resets. The fuel pressure and burner nozzle determine the running temperature. A panel mount or in-line thermostat could be installed fairly easy if you wanted the option to control the temperature.
 
Thanks for the feedback guys. My system has a high limit switch but I have never tested the water temperature.

Russ, what should be a normal operating temperature without having a thermostat? Does can the fuel pressure be adjusted to increase the temp?
 
Russ, what should be a normal operating temperature without having a thermostat?
180° - 200°is usually the preset temperature.


Does can the fuel pressure be adjusted to increase the temp?
you can get a 20° adjustment range playing with the fuel pressure. Don't go too far, though, especially with a 12 volt burner. If you adjust up too high, the fan may not be able to supply enough air to keep it from running rich. If it runs rich, it will soot up.
There, too, the air shutter will have to be adjusted for the new fuel pressure. There's a fairly narrow band between too rich and too lean.

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"sustainable" heat vs. ADJUSTability

What regulates water temperature from burner if there is no adjustable thermostat?

SEVERAL things control temperature..
a few are mentioned above, but here's how I explain it in a general context..

Look at it as a fire-ball with a coil of water over it..
the bigger the fire, the more heat you can get in the water.
And.. the incoming temperature and FLOW allow a net increase in temperature..
the lower the flow, the higher the temperature..
..all with the Same SiZE fire.

as a separate issue, the fire-ball is chosen by fuel pressure,
and burner-nozzle size. once there, you has to give it "enough" air to breathe,
and suffice it to say, too much air is a whole added "can-o'Worms"
.. kinda like facillitating a drunk. Eh? :alcoholic:

For a "controlled system" with a defined function..
We "choose" a particular flow-rate for our system,
and relative to INcoming water temp, we add a "fire Ball",
of size efficient to run with "stability"..
You DON'T really want it to shut down, in the middle of running,
or the temperature gets a "mood swing."
Now, why would you want to make your machine a "moody-girl". Eh?
So,
a temperature-limit switch is the SAFEST control when chosen at
"slightly" over the expected working temperature of the system.
We call that a "tight safety". Same as we choose a fuse on an electrical system.
When you use a adjustable temp control, you can "force" the temp down, but she get's all moody..
the lower you force the temp down, the bigger the mood-swing in temperature.
And, the less "accurate" your temp control,
the more she acts menopausal and bipolar. Eh? :jester:

Now stop laughing.. I'm serious here..
the tighter you keep control over yer equipment,
the less likely you will have to take any "extra heat",
and the more "sustainable" your "relationship".

I figure to some of you,
are going to realize you have an issue of temperature control, but others..
this also means you also should throw condoms in your tool box.
 
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