Is this boiler option worth using?

cnmdesign

Header Sensor - When this sensor is installed and enabled, the boiler will attempt to maintain the target water temperature in the header rather than in the supply.

Where the system flow rate varies widely, the use of a header sensor allows the temperature of the water being sent to the radiation to be more accurately controlled. Using an Alpha2 on the secondary.

Page 83

https://www.ecomfort.com/manuals/K2_Installation_Manual.pdf

Thanks

hot_rod

If that is a water tube type boiler it probably holds about a gallon of water. By adding a hydro separator or low loss header you will add some fluid capacity to the system.

In this example the piping and separator could triple the volume the boiler "sees" Provide a small amount of buffer for the boiler. The sep has a sensor well port near the top specifically for that option.

Some installers add that sensor down stream of the sep on the system supply piping to get an exact SWT to the system for control and ODR accuracy.

cnmdesign

<blockquote class="Quote" rel="hot rod"

Thanks for reminding me. My system does have a Caleffi 4n1 all ready installed.

This is the required sensor, which one will work best, the short or long or neither?

http://www.furnacepartsource.com/honeywell-32003971-003-single-element-sensor-assy-42/

If you go back up to the manual on page 82 you can see what looks like a two screw terminal. So should I get the long one with two wires, and if so, will it fit? If I have to get the short one with three wires, which one should I not hook up?

To me, it looks like both are included in the order. What do you think?

hot_rod

Here is the well Caleffi offers for those Seps. It should accept most all of those 6mm sensors that are common with mod cons these days. Note it is a straight thread and seals with a gasket.

Installers tell me a 1/2 npt well will work with a few extra wraps of teflon tape

Really, only the tip of those sensors need to be in contact with the well. When you cut one open the actual thermistor is at the very tip, similar to a thermocouple in a water heater.

Use a short well as there is a mesh inside the Sep 4 that a long well might not fit.

Here is the sensor and well that comes with Lochinvar boilers. add a 1/2 bushing if the well is a 3/8"
They also include a reducing sleeve if you use a typical off the shelf well, like Honeywells with a 1/2 ID hole.

I've also found if you fasten a sensor to the outside of a copper pipe with a stainless hose clamp, and INSULATE around it, it will read exactly the same as one in a well. The copper is an excellent conductor.
I've seen wells installed in copper tube pin hole from excessive velocity flowing across them, plus they add some pressure drop.

A well in a tank is the best way, for copper tube, strap it on is a workable option.

Here is a method I use for solar work when a sensor needs to be installed on a collector, use an electrical lug with a hose clamp.

cnmdesign

<blockquote class="Quote" rel="hot rod"

Thanks for the info, but back to my original question.

Is this option worth taking advantage of?

Thanks

hot_rod

cnmdesign said:

How much control accuracy do you want, or need? There is no question that positioning the sensor closer to the load will have faster and more accurate control. If the cost is minimal, why wouldn't one do that?